: Fixed the egr valve myself



laurieH
01-08-04, 03:37 PM
HI,

I went ahead and took off my valve yesterday and cleaned it. I used carb cleaner and a wire brush and after working on it for about 20 minutes it came unstuck (there was a piece of carbon chunk lodged in it) and it works fine now. I drove the car last night and today and actually put about 50 miles on it with all thedriving I had to do and my engine light is off and car is running much better. I was surprised at how easy it was to remove and reinstall.

I have an appointment at our local cadillac dealership next week to do the carbon cleaning on my car. It is expensive but I figured I may have very well saved myslef more by cleaning this part and better get it done. I also am getting new sparkplugs there but am passing on the wires.

I realize I may have a carbon problem still ( I am sure I do) and hopefully the cleaning fixes this.

Someone wrote me about maybe the previous repair I had done may have casue this so I wanted to talk about that again. I found my reciept and will list the parts I got put on with that oil leak I had, I also have part numbers if thats needed but wont list that just yet.

lower crank case seals
oil manifold
oil pan gasket
front crank seal
valve cover right
valve cover left
timing cover gasket
front mail seal
rear main seal
Did they open something up here and not clean it??? Causing all this carbon debris to go into my EGR??????

I am not taking my car there again, I am only going to cadillac from now on. I am hoping after I get the cleaning done and new sparkplugs my car is running great.

I am upset wit myself for this major repair I had done. I always try to check around and get very involved when I have car problrms but when this one struck I had a lot going on that was more important and I just okd the work. I did have a major oil leak and couldn't drive the car and needed it fixed. I was referred to this mechanic by someone and I wish now I would never have gone here. If I was going to spent that kind of money I should have went to cadillac. I took my car to cadiilac for jut about everything else expect brakes (which I was told could really get those done anywhere by the cadillac man himself.) Well, anyway I am glad my car is running better and I will use the money I would have spent on the egr to get my car carbon cleaned adn new plugs. I think that sounds like a good investment.

Laurie

Logandiagnostic
01-08-04, 03:48 PM
As mentioned before. You really cannot avoid the carbon build up. EGR valves live in the exhaust stream. The valves will naturally get carboned up. Save your money and just plan on cleaning the EGR valve every 40-50,000 miles.

To help avoid carbon buildup. Drive the car harder once in a while. Full acceleration on a highway on ramp should fix any carbon problems.

Logan

ellisss
01-09-04, 01:42 AM
The valves will naturally get carboned up. Save your money and just plan on cleaning the EGR valve every 40-50,000 miles.Sorry, but I disagree.

My suggestion would be to do the cleaning once, modify maintenance and driving habits to reduce carbon build-up in the future, and forget about ever having to clean the EGR valve again.

I've offered those suggestions to dozens of Cadillac owners, and no one who has followed them ever seemed to need continual EGR valve services... or even the expensive engine cleaning ever again.


To help avoid carbon buildup. Drive the car harder once in a while. Full acceleration on a highway on ramp should fix any carbon problems.WOT runs do not unstick 2nd or 3rd piston ring carbon saturation, which is where the majority of Northstar oil comsumption comes from (leaks not included).

WOT runs do not clean clogged injectors.

WOT runs won't unstick a sealed by carbon EGR valve.

WOT runs won't remove carbon from EGR passages.

What WOT runs will do is to unstick a saturated 1st piston ring, as long as there isn't so much carbon accumulated in the ring groove as to completely hinder it's movement.

My opinions and suggestions are based on almost a quarter century in the industry, five years as a Cadillac technician, and over 1000 hours of GM training with 75% of it being Cadillac. The Northstar engine cleaning procedure that I'm hawking on here was derrived from manufacturer-based testing done on hundreds of test beds and field-tested on an equal number of Northstar motors owned by regular people.

Uhhh, not trying to 'shoot the messenger' here, either.

--
Ellisss.

ellisss
01-09-04, 02:19 AM
I went ahead and took off my valve yesterday and cleaned it. I used carb cleaner and a wire brush and after working on it for about 20 minutes it came unstuck (there was a piece of carbon chunk lodged in it) and it works fine now.
Good for you, LaurieH. The Northstar is an intimidating assembly. Kudos to you for rolling-up your sleeves and jumping in.


I have an appointment at our local cadillac dealership next week to do the carbon cleaning on my car. It is expensive but I figured I may have very well saved myslef more by cleaning this part and better get it done. I also am getting new sparkplugs there but am passing on the wires.
Another excellent decision. Don't forget the cookies or doughnuts. :bouncy: I'll say it again... dealership service writers and technicians who are on the receiving-end of kindness and good-natured gestures by car owners will take huge steps to service you (and your car) above and beyond the normal.


I realize I may have a carbon problem still ( I am sure I do) and hopefully the cleaning fixes this.
It will, but please remember that you should also modify your maintenance and driving habits to lessen the accumulation of carbon in the future.

Good fuel (Mobil or Chevron), an occasional can of BG 44K in a full tank of gas (maybe once or twice each year), always allowing the motor to reach operating temperature, and the occasional intake system cleaning (much less expensive than the engine cleaning you'll be getting) will do wonders to curb carbon build-up in your engine.

As Logan has stated... the occasional wide-open throttle run (done safely, please) will also remove some of the carbon accumulated in the top of all the cylinders.


Someone wrote me about maybe the previous repair I had done may have casue this so I wanted to talk about that again. I found my reciept and will list the parts I got put on with that oil leak I had,

lower crank case seals
oil manifold
oil pan gasket
The crankcase of a Northstar is in four pieces... the oil pan, the oil manifold, the lower bearing cradle, and the engine block itself. To replace the seals along the sides of the lower crankcase and the oil pan, a mechanic seperated the bottom three pieces of the engine from the block assembly. The entire powertrain should have been removed from the vehicle... and it's an expensive repair. (see my 'Hello' thread in the introductory forum to see a picture of me doing this.) There is little possibility that any crankcase carbon accumulation found it's way into your EGR system. More likely, the EGR valve passages were already dirty with carbon, and possibly the repair caused some carbon particles to dislodge and clog or stick the EGR valve.



front crank seal
valve cover right
valve cover left
timing cover gasket
front mail seal
rear main seal
All of that is nowhere near the EGR or intake system. Again, having the motor operated on so drastically probably disloged some carbon that was already present in the intake or EGR system(s).


Did they open something up here and not clean it??? Causing all this carbon debris to go into my EGR??????
Heh. They opened-up everything.

Would a decent mechanic have offered you the opportunity to spend the extra money on de-carbonizing the intake and EGR systems? Yes. Is it possible that they didn't want to scare you off with suggestiong that you spend even more money? Yes. Is it likely that someone thought if you had carbon problems later (after the expensive oil leak repair), that you would be back to spend more money? Yes.


I am not taking my car there again, I am only going to cadillac from now on. I am hoping after I get the cleaning done and new sparkplugs my car is running great.
That's okay, but if you can find a reliable, honest, and trustworthy shop that isn't a dealership... don't hesitate to give then your business instead.

I was a class-A Cadillac technician for five years. I've found that there are some dealerships that don't deserve people's money due to poor service. Likewise, there are independant shops that will rip you off to an extreme. You need to do the leg-work and find a reliable shop... although a Cadillac dealer will have access to better information and more specialized tools and procedures.

Good luck in the future, Laurie. Remember about the cookies or doughnuts.

:bouncy:

--
Ellisss.

Logandiagnostic
01-09-04, 05:39 AM
No cookies or dounuts for us please.

I guess we are in a situation where we have to 'agree to disagree.'

There is no sense in paying $2-300 for a decarbon job if she does not need it.

Her EGR tubes etc may be fine. If the code comes back....maybe then we can talk about the option of them needing to be cleaned.

Do you even own a car with a Northstar?

Do you even have one of these?

http://images.andale.com/f2/115/106/3768672/1056786545085_tech.jpg

This one happens to be ours.

Logan

Logandiagnostic
01-09-04, 05:46 AM
Yeah.......and this too. Please no 'in tank' fuel injection cleaners. It melts the insulation off the field windings on the fuel pump. Fast way to a fuel pump failure.

Logan

zonie77
01-09-04, 09:29 AM
I asked which gaskets they changed. I don't think they caused it directly (having the EGR apart and not cleaning). I think they pulled the engine to change the seals and the chunk of carbon came loose or got moved because of the moving . It might have happened anyway if you hit a bump hard enough.

ellisss
01-10-04, 03:32 AM
I guess we are in a situation where we have to 'agree to disagree.'
Agreed.


There is no sense in paying $2-300 for a decarbon job if she does not need it.
Okay, now can you tell me what about her situation has led you to believe that she doesn't need a thourough cleaning?


Her EGR tubes etc may be fine. If the code comes back....maybe then we can talk about the option of them needing to be cleaned.
"Her EGR tubes may be fine" isn't a statement that someone with plenty of Northstar experience should be saying. That is, instead, an opinion based on nothing but dreamy assumptions that have no factual basis in the reality of her situation... which by the way, she explained almost perfectly.

If her EGR passages were 'fine' then where did the carbon particle that was holding it open come from?


Do you even own a car with a Northstar?
Ohhh, I see. Now you're going to say that because I don't own a Northstar... I can't possibly know what I'm talking about. No, Logan, I don't own a Northstar. I have, however, spent a great deal of time in my life not only diagnosing and repairing them, but also receiving many hundreds of hours of Northstar-specific training. I've trained dozens of b- and c-class technicians on Northstar diagnostic and repair procedures. I've diagnosed, repaired, swapped, and torn-down/reassembled hundreds of Northstar motors.

Did you want to agree to disagree... or do you want to compare educational and work backgrounds? Pick just one, please.


Do you even have one of these?

http://images.andale.com/f2/115/106/3768672/1056786545085_tech.jpg
Do I own one? No, of course not. Do I have access to three of them? Yes. Have I sent in for repair or replacement more of them than you have had your hands on? Undoubtedly.

The Tech2 is a GM-specific tool. The scan tools I use are more generic. The shop I'm at now recently purchased three Snap-On MODIS units, one with a 5-gas on it. We also have a Fluke 867B.

I'm sorry that it (seemingly) makes you defensive to have someone disagree with the suggestions you tend to give.

--
Ellisss.

ellisss
01-10-04, 03:36 AM
Yeah.......and this too. Please no 'in tank' fuel injection cleaners. It melts the insulation off the field windings on the fuel pump. Fast way to a fuel pump failure.

Logan
Oh, that's rich. BG 44K harms fuel pumps?

... sure it does, Logan. :histeric:

Maybe it's because my suggestions are geared towards empowering the owners of Northstar engines against the need for constant return-trips to a shop (like yours, maybe?) for cleaning service after cleaning service.

--
Ellisss.

Logandiagnostic
01-10-04, 10:13 AM
We work for GM...so we do have a clue whats going on. And I dont mean at the stealership level.

I dont think she ever did mention the year car she is driving. The assumption is she simply has a EGR position code.

From the GM service manual....there is a EGR cleaning procedure-

"The EGR system should be inspected and cleaned whenever the EGR valve is removed, or during regularly scheduled EGR system maintenance. This routine inspection and cleaning will insure that the EGR system will function properly under all operating conditions. An EGR System Diagnosis should be performed if required by engine performance or engine driveability symptoms and no PCM DTCs are set . "

Now IF the code returns. I would buy into maybe having the cleaning procedure done. I suspect you are mentioning procedure TSB #02-06-01-009.

EGR valves by their very nature will collect carbon. I dont think I have ever seen a 'clean' EGR valve after some miles of usage. It would appear that you recommend every dirty/stuck EGR valve should have the engine decarboned. That simply is not the case.

As for injector cleaners. This quote is taken from a current Northstar enginner.....

" Save yourself the last bit of expense and grief and DO NOT have the injectors and/or fuel system flushed. You know how I hate any sort of flushing. If it is running good now, for get the injector flush. You do not need to introduce some harsh chemical cleaners into the injectors or fuel rail. Since any solvent will circulate around the electrical windings in the injectors you run the risk of damaging the insulation on the windings with solvents. Same for fuel additives or flushes for the tank. The gas circulates thru the windings in the armature of the fuel pump and solvents can damage the windings. DO NOT FLUSH. Leave well enough alone."

Logan

Stoneage_Caddy
01-10-04, 01:08 PM
whoa , does the injector cleaner thing apply to all GM products ?

i always thought windings were in a sealed enviorment where combustable matriels couldnt get in ? like in the injecotrs i thought the pintle rode in and out of a seal where the solenoid was behind the seal away from all the nasty stuff ?

ellisss
01-10-04, 02:10 PM
We work for GM...so we do have a clue whats going on. And I dont mean at the stealership level.
Cute. So, aside from collecting, repairing, and selling tail lamp assemblies... what else do you guys do?

http://www.logandiagnostic.com/


I dont think she ever did mention the year car she is driving. The assumption is she simply has a EGR position code.
Right. ... on a Northstar motor. She also posted about removing the valve herself and seeing that it was being held open by carbon. In my experience, 2 + 2 always = 4 ~~ and Northstars that get driven daily accumulate carbon to an extreme.

If you recall, my opinion was that carbon is a problem for all motors, and especially for the Northstar due to inherent design flaws. I also posted my opinions on how to effectively deal with carbon and change some basic habits (maintenance and driving) to lessen the build-up of carbon in the future.

My suggestions are effictive, simple, and originate in common sense. As far as I'm concerned, they have been proven in real-word situations. The customers that I have dealt with in the past, who I determined to have drivability issues due to carbon problems, and who chose to follow my suggestions on cleaning and changing their driving and maintenance habits, have all been highly satisfied with the results. Nobody ever needed a second engine cleaning. Nobody ever (to my knowledge) needed additional EGR system services due to carbon contamination. All of this is 'real-world' stuff that works, and isn't covered in any TSB or by an overly egotistical engineer posting notes anonymously on some web site.


From the GM service manual....there is a EGR cleaning procedure-
Technicians who view TSB's and the factory repair procedures as the do-all and end-all when it comes to proper diagnosis and repair are nothing more than drones. Robots who can do no thinking for themselves based on common-sense and real-world situations. That is my opinion. Personally, I always used TSB's and factory procedures as a starting point... and then create a maintenance schedule and other procedures based on a per-situation basis. I've found that when the book is followed to-the-letter, the first casualty is the owner's bank account... and the second one is the trust between vehicle owner and technician that most shops work so hard to build.


EGR valves by their very nature will collect carbon. I dont think I have ever seen a 'clean' EGR valve after some miles of usage. It would appear that you recommend every dirty/stuck EGR valve should have the engine decarboned. That simply is not the case.
Okay, Logan... I'm thinking you really aren't reading all of my posts, and you didn't see my detailed explanation of the carbon removal procedure using the new Kentmore tool kit. It includes an EGR adapter plate where solvent is forced through the entire EGR system. It removes all carbon from the motor, except for crankcase deposits which would be eliminated over time simply by changing the oil properly. How much would only the EGR sevice cost? Now, compare that number to the cost of having the entire engine (again, sans crankcase) cleaned of carbon. Pennywise and pound foolish there, isn't it?

For someone who stated that we just 'agree to disagree' ... you sure are keeping the fire burning, Logan.


As for injector cleaners. This quote is taken from a current Northstar enginner.....
:histeric: Current Northstar engineer? :histeric:

Oh, puh-leeze. Some of those guys take 30 minutes to tie their own shoe laces. I bet the manufacturer, along with it's highly-paid engineers, would rather you just replace injectors that clog or become dirty enough to cause drivability problems. Those same goofy engineers were the ones who decided that ABS harnesses didn't need soldered terminals on the low-voltage data lines... which caused extreme amounts of problems for Northstar owners and millions of dollars in warranty repair costs for the company. I'm not an engineer, and I could have told them that they would have needed to solder the terminals to prevent signal corruption.

As far as BG 44K being a harsh, corrosive chemical that will damage injector and fuel pump windings... that isn't true. Maybe you can collect all the people who use it, and benefit from it... and create some kind of class-action suit against BG.

Believe it or not, Logan... I actually appreciate your input. You are entitled to your own opinions, as I'm entitled to mine.

--
Ellisss.

ellisss
01-10-04, 02:17 PM
whoa , does the injector cleaner thing apply to all GM products ?
Don't believe everything you see on the internet. :halo:

Real Cadillac engineers wouldn't be caught dead putting their actual names on anything posted outside of the company's control.


i always thought windings were in a sealed enviorment where combustable matriels couldnt get in ? like in the injecotrs i thought the pintle rode in and out of a seal where the solenoid was behind the seal away from all the nasty stuff ?
Hey, look at that... and you're not even an engineer.

I can't speak for anything except BG 44K... but that particular chemical is entirely safe for fuel pumps and injectors.

--
Ellisss.

Logandiagnostic
01-10-04, 04:35 PM
For Stoneage: The fuel flows right thru the pump windings etc. The fuel is used to cool the windings. In tank cleaners can also damage the rubber fuel hose in the tank.

As for the 'Cadillac' Northstar engineer. Well known and available on www.caddyinfo.com . He does use a screen name. But some of us know who he really is.

$2-300 to clean the EGR tubes etc. She may have to if the code comes back. To do so the EGR has to come back off anyways. Just suggesting a wait and see. I think most of our customers understand this. They sure as hell dont want to pay $2-300 if the problem perhaps will not occur. Maybe thats why they gave up on dealership service years ago.

I agree that TSBs and service manuals can often be misleading and even incorrect. The factory service manuals are nice and a must have...but you also have to understand whats going on also. I'm sure we have both seen problems where the service manual suggests a cure. But is not even close to the root cause of whats really going on.

As for us...been with GM since 1981. Driveability diagnostics. We can also be found here-

www.airbagcrash.com

Logan

ellisss
01-11-04, 12:48 AM
For Stoneage: The fuel flows right thru the pump windings etc. The fuel is used to cool the windings. In tank cleaners can also damage the rubber fuel hose in the tank.
... and I'll say to Stoneage_Caddy that, while there are surely some chemicals that will damage in-tank parts, BG44K isn't one of them. Logan, if you don't believe me, then why don't you take a 2-inch length of fuel line and soak it in a 10:1 mixture of fuel and 44K for a week or two. Let us know what does or doesn't happen.


As for the 'Cadillac' Northstar engineer. Well known and available on www.caddyinfo.com (http://www.caddyinfo.com/) . He does use a screen name. But some of us know who he really is.
Some of you, like the ones who have banner advertisements on the front page of his caddyinfo site? Nice advert you've got there, Logan.

Is Bruce Nunnally his anonymous name, or his real one? I wonder if he does work for Cadillac, and whether or not they know what he does in his spare time. Personally, I think he works for Texas Instruments... but I could be wrong. I doubt he's an engineer who has anything at all to do with Cadillac except fo driving one.


$2-300 to clean the EGR tubes etc. She may have to if the code comes back. To do so the EGR has to come back off anyways. Just suggesting a wait and see. I think most of our customers understand this. They sure as hell dont want to pay $2-300 if the problem perhaps will not occur. Maybe thats why they gave up on dealership service years ago.
Here we get to see a small sample of your short-sightedness. Carbon happens in Northstar engines to an extreme. You would choose to remove and clean only the EGR valve, ignoring the root cause of the problem and allowing the remaining carbon in the system to propogate and continue to cause problems for the customer... necessitating continual return-trips to the repair shop in order to try, time after time, to alleviate the problem.

My solution to the problem is to eradicate all carbon, everywhere except the crankcase, giving the car a clean slate, so to speak. From that point, the customer can modify their maintenance and driving habits to prevent the problem from ever occuring again. That prevents them from coming back time and time again for the same problem. If the customer chooses to not change the part of the equation that is under their control (maintenance and driving habits), then there is nobody to blame but themselves for the continual flow of money from their bank accounts to the cash register.

My solution = spend the money now, get rid of all the carbon, change some simple habits that contribute to the problem, and never have to deal with it again.

Your solution = spend less money now, don't fix the root cause of the problem, and hope against all logic that it won't be an issue in the near future.

... can anyone say 'duh'? :bonkers: It's called being pennywise and pound foolish. It's also called not being fair to your customers. I do suppose, however, that if you're sneaky enough about it that they'll never know the difference. You and I know that the only thing that benefits from your solution is your cash register.


I agree that TSBs and service manuals can often be misleading and even incorrect. The factory service manuals are nice and a must have...but you also have to understand whats going on also.
I'm not sure if I should thank you for agreeing with me on that single point, or ask you if you're trying to insinuate that I have less than full knowledge of what is going on under the hood of a Northstar. :confused:

I've spent years getting my hands in it directly... unlike some technicians who would rather sit in the driver's seat with a Tech2 and make a less-than accurate diagnosis leading to a less-than complete repair which causes the owner to spend more money than is necessary over a longer period of time.


As for us...been with GM since 1981. Driveability diagnostics. We can also be found here-

www.airbagcrash.com (http://www.airbagcrash.com/)
That is a dead link for me, and Google's cache is a blank page.

If you're business is what I think it is (independantly owned diagnostics and repair), then I can uderstand your animosity towards dealership service departments. What I can't understand is that you call dealership service departments 'stealerships', refusing to admit that there are those of them that have exemplary standards and highly-qualified technicians. It's a slap in the face to those of us who take pride in our work, and have labored long and hard to achieve the knowledge and techniques that we have.

It's almost like you don't think that any dealership technician can come close to the know-how and honesty a good, decent, and honest independant shop can offer. That is complete b^llsh^t.

So much, I suppose, for agreeing to disagree. :rolleyes:

--
Ellisss.

Logandiagnostic
01-11-04, 01:07 AM
No...you dont understand. I work for GM.

Bruce Nunnally is simply the site owner of caddyinfo.com. We do not pay for the banner ad on caddyinfo.com.

The Cadillac engineer on caddyinfo.com goes by the screen name 'Bbobynski.' Not trying to hide anything there.

The server for our www.airbagcrash.com website was down earlier. There is a sister site which has basically identical information-

www.crashdatainfo.com

I dont care if you charge customers for the carbon cleaning job. They do. If we have this type of situation come up....we explain exactly the situation to the customer. Wait and see if the code returns. I think most perfer to wait and see.

Logan

ellisss
01-11-04, 01:38 AM
No...you dont understand. I work for GM.
Fair enough... although you're being more than a little misleading there. What exactly do you do for GM... rebult tail light assemblies? Download crash data from SIR modules? You surely don't do warranty repairs.

I'm seeing a pattern here: You make a statement, I reply and bring up multiple points, and you reply without addressing most of the points I brought up. I'm not trying to argue with you, but if you make statements that I disagree with, please don't expect me to keep my fingers from typing. I'm noting that you are no longer wondering if I own a Northstar... or know what a Tech2 is. Did I convince you that I know what I'm typing about?

As far as the EGR carbon issue... you seem to think that whatever carbon is there won't move, grow, or dislodge and hold open the valve. You also seem ignorant of the simple changes that drivers can make in order to curb or stop completely the growth, accumulation, and spreading of carbon particles.


Bruce Nunnally is simply the site owner of caddyinfo.com. We do not pay for the banner ad on caddyinfo.com.
Thank you for the clarification.


The Cadillac engineer on caddyinfo.com goes by the screen name 'Bbobynski.' Not trying to hide anything there.
No, maybe you're not... but he sure is. I'll say again that most (or at least many) of the engineers employed by Cadillac are goofballs. A copmpetent field-engineer could do their job 100% better.


Wait and see if the code returns. I think most perfer to wait and see.
Hmmm, I see. All of my customers dind't want to come back at all for the same problem, only to be charged for services I've already performed. When offered the opportunity to not only increase the car's performance and reduce oil consumption, but also prevent a return trip for the same issue (EGR carbon)... they all could plainly see the advantage I was giving them.

I guess some people wouldn't want to 'kill many birds with one stone', as the saying goes.

There is something to be said for offering multiple advantages to many situations by performing a single service... instead of the 'wait and see' attitude that you take. To each his own, though.

--
Ellisss.

Logandiagnostic
01-11-04, 02:20 AM
I work for GM. Lets just say Bowling Green facility. What exactly I do for them is not related to this post. I'm not asking where you work and what you do and why.

We do not do warranty work for GM. We do perform some work for some select Cadillac dealerships/cadillac repair shops relating to LED brakelights, along with some Acura dealers. We do not download SIR data for GM. I'm sure they can get that on their own.

The 'bbobynski' on www.caddyinfo.com .....I think you would be more than welcome to visit that website and ask him. He use to use his real name up until about a year ago. Interesting....it was another wall banger like you that forced the change.

This post is an excellent example. We have long ago forgotten about the original post. PO36?...she took it off....cleaned it...no code.. Cost for her $0.


Logan

ellisss
01-11-04, 03:09 AM
This thread has admittedly gone somewhat off-topic. Anytime you wish, Logan, I can start a new thread where we can discuss things more publically. Oh, wait a minute... it's not really a discussion. You make statements that I disagree with, and when I reply with plenty of valid points... you ignore them.


I work for GM. Lets just say Bowling Green facility. What exactly I do for them is not related to this post. I'm not asking where you work and what you do and why.
No, but your comment on 'stealership' service departments was an antagonistic jab at what I did for a living, and devoted many years of my life to. It was an insult to both my intelligence and my character. Now, when I bring up (without the snide jab, as you did) what your job entails... you're suddenly claiming serenity. Riiight. :rolleyes:

I put forth that most of your work is repairing or rebuilding LED lamp assemblies for both dealership service departments and independant shops, and providing crash data for the private sector by downloading it from SIR modules that are from vehicles that were involved in crashes. The rest of your work may (or may not) be drivability diagnostics and/or minor repairs.


The 'bbobynski' on www.caddyinfo.com (http://www.caddyinfo.com/) .....I think you would be more than welcome to visit that website and ask him. He use to use his real name up until about a year ago. Interesting....it was another wall banger like you that forced the change.
Damn straight I'm a wall banger. I do it long and hard when I see something that causes my b^llsh^t alarm to sound. You have practically broken it, Logan. :)


This post is an excellent example. We have long ago forgotten about the original post. PO36?...she took it off....cleaned it...no code.. Cost for her $0.
You are so funny. Do you really believe that without a thourough cleaning, that her problem won't come back? Who in their right minds would rather spend a couple of hours every time the problem rears it's ugly head, instead of getting rid of the problem and doing some simple, common-sense things to prevent it from ever happening again?

Here... these are your words, Logan: "Save your money and just plan on cleaning the EGR valve every 40-50,000 miles."

News flash #1: A carbon-saturated EGR system will set EGR failure codes much more often than every 40-50K miles.

News flash #2: Carbon particles live in the entire EGR system, not just the valve. Cleaning the valve cures the symptom, not the problem. For someone who supposedly 'works with GM', and who also supposedly has some knowledge of factory repair procedures... you sure do seem plenty uninterested in dealing with the root cause of a problem, thereby saving the vehicle owner money instead of causing them to pay more and have an increased number of trips to your shop.

News flash #3: EGR system carbon contamination is but a single problem that arises from the Northstar's inherent design flaws that allow carbon to accumulate and cause problems. Oil consumption, reduced mileage and performance, and increased emissions are some of the other symptoms of carbon contamination. My method of dealing with this is simple and all-encompassing. Your method doesn't address anything else but the SES light. You are continuing to completely ignore this.

In my most humble opinion, it's techs like you who give the rest of us a bad reputation.

--
Ellisss.

Logandiagnostic
01-11-04, 03:49 AM
I would recommend a new post. I'm fine with that.

Bad tech? Its the stealerships that keep us in business!

We do in fact work for GM.

FACT....we draw a paycheck from the General every week. The websites are just bonus income. Plus we save people gobs of money.

EGR valves.....as mentioned before. They live in the exhaust stream. They will get dirty. Clean them and they are ok for another 50K.

As mentioned...she cleaned it...no codes....run with it......

Logan

Realtor1
01-17-04, 08:55 PM
WOW! Thats was fun reading :bonkers:

Bowling Green Plant caught my eye as I am 45 Min from B.G. Me personally am kinda curious as to what you do there at the corvette plant. Seen any XLR's I heard there is a couple in BG....You drive from Bashville to B.G?

Let me know the new thread as I for one would like to continue reading this saga..... :)

97 concours
01-17-04, 11:23 PM
Very Entertaining guys......

BeelzeBob
01-18-04, 01:24 AM
:histeric: Current Northstar engineer? :histeric:

Oh, puh-leeze. Some of those guys take 30 minutes to tie their own shoe laces. Ellisss.


That's why I wear cowboy boots all the time....so I don't have to tie my shoelaces....LOL

Ellisss....you are truely a piece of work with some of your ranting. Why don't you come on up here to Detroit and help us poor Northstar engineers out and roll away the stone for us so we can see the light. We could use a good laugh.

Anyway....

Did anyone think to ask the original poster if she had a 93 or 94 Northstar? If it is one of the early year engines it might also need the phenolic spacer plates cleaned out due to carbon build up in the EGR passages. Those will clog with carbon over many years/miles also.

Carbon or coke is an inescable part of any EGR system.... The exhaust gas forms the coke within a specific temperature range as the exhaust gas cools. That is why the Northstar EGR system is cooled by the coolant in the water crossover. There is a large passage that runs the width of the water crossover to the far side and back that is designed to transition the exhaust gas thru the coking temperature range within the large diameter passage. The passage is large enough that it will likely never be able to clog with carbon (and there are screwed in pipe plugs in each end to clean it with if it does) so that most of the coking will be done within the passage and not the valve. Having said that, the shaft of the valve will still build some deposits that look more like varnish than carbon or coke. THAT is what is happening to the valve over high miles. The shaft starts to get sticky in the seal and the code for EGR pintle position sets. Cleaning just the shaft of the EGR valve inside the cast in passage in the base will solve the problem.

Use a lot of care cleaning the shaft with solvent. If solvent runs down the shaft and into the can of the valve it will likely ruin the valve as it will eat the insulation off the wire windings inside the valve. Keep the valve right side up when using solvent to clean the shaft inside the base and/or wrap the shaft outside the base with a rag to keep any solvent from reaching the can itself.

I have personally seen a LOT of fuel pumps and injectors ruined by various aftermarket fuel treatments and solvents meant to clean injectors and such. Unless there is specific test results that indicate a solvent is "safe" for injectors and fuel pumps I would expressly avoid them. One of the problems with solvents and additives is that they may be harmless if used correctly...i.e...diluted into 18 gallons of gas or whatever....but....many people ignore this and pour the solvent into a partially filled tank and ruin pumps and injectors due to the stronger concentration. Even "safe" solvents can damage the systems if used in this way. I specifically know of one such typical case where an owner poured a fuel treatment into his nearly empty tank to drive to the gas station about 1 mile away. His pump failed before he had run that tank of gas out due to the damage done on that 1 mile drive with the strong , concentrated solvent in the fuel. Be aware.

The fuel contacts the windings in fuel pumps and injectors....it flows directly over the windings to cool them. The windings are not isolated from the fuel at all. Take an injector or fuel pump apart and see....

Stoneage_Caddy
01-18-04, 01:56 AM
[QUOTE]

The fuel contacts the windings in fuel pumps and injectors....it flows directly over the windings to cool them. The windings are not isolated from the fuel at all. Take an injector or fuel pump apart and see....


i might do that one day , only injectors ive had apart are from 2 stroke detroit diesels and 6.x series gm pickup diesels and boath were training cutaways

also what does it take education wise to be a engineer at GM ? and what is it like? for awhile i wanted to be one and abandon the idea thinking i would never get to work with the nuts and bolts of the beast and just end up handing formulas to a designer on the mean effcetive compression ratio....(aka doing everyones math problems wist they sort out/design the car)

BeelzeBob
01-18-04, 02:13 AM
what does it take education wise to be a engineer at GM ? and what is it like? for awhile i wanted to be one and abandon the idea thinking i would never get to work with the nuts and bolts of the beast and just end up handing formulas to a designer on the mean effcetive compression ratio....(aka doing everyones math problems wist they sort out/design the car)
First off it takes a college degree in one of the engineering fields...mechanical, electrical, etc... Going to a school that GM recruits from helps a lot as well as co-oping at GM during your college training to get some exposure on the job. You have to have good grades with that degree or you will not get past mailing your resume in....

There are a myriad of different engineering jobs at GM. Some involve a lot of simulation/calculation...others are very practical in nature..i.e...you get a lot of hands-on experience. As an example, doing engine dyno development on a new engine or varient of an existing engine involves hours and hours of dyno work including designing and fabricating the dyno set up, wiring harness, PCM, fuel system, etc...and then making it all "play". Then designing and organizing the test parameters, data collection, etc. You would work on everything from the mechanics of the fuel supply system and cooling sytem on the dyno to sorting out the calibration of the fuel injection and ignition timing. LOTS of hands on. There are engineers that design the parts and release the parts for production. A release position requires a lot of experience as it ties together all the disciplines from evaluating the design, working with manufacturing to assemble the parts onto the engine/car, working with the parts supplier to manufacture the part, etc....

Keep in mind that there are engineers required in all areas of the car...from the bumpers and crash systems to the fuel system, interior occupant protection, powertrain, body, body assembly, etc.....thousands of different types of engineers. Also specialists like metalurgists, chemical engineers, etc. You can basically work on just about any type of engineering job you want at a car company.

Stoneage_Caddy
01-18-04, 02:26 AM
sound pretty damned awesome to me

the college i looked at had a "mechanical engineering" program but they had no clue if it would apply to the automotive world

and there is nothing in florida that would aid me into my number 1 dream job as a designer like john caffaro/wayne cherry . it appears the only schools for what they do are in san fran and in michigan so for right now im persueing journalisim


anyway thanks for your awnser dude


sorry to jack this thread , not often i see a GM insider thats willing to give me the time of day

clay
01-26-04, 04:42 PM
Back to the original topic briefly...I would like to remove and clean my egr valve, since I have been getting the same code. I know where it is, but don't know how to get the fuel lines out of the way. I have a '95 SLS which shares one EGR bolt with a fuel line bracket. Someone suggested taking off the intake manifold bolts and moving it to the side to make room...if that is the answer, where are those bolts and what does the intake manifold look like? I also read of plastic brackets that can let the fuel line loose...I can't see them.


Thanks,

-Clay

BeelzeBob
01-26-04, 05:12 PM
On a 95 with the plastic intake manifold (that is the large black plastic piece with the shape of the individual intake runners molded in the upper surface) the fuel rail is retained with a plastic barbed snap fit arm that mates with a detail in the intake manifold itself. If you look carefully at each fuel injector pod there is a black plastic mounting and securing detail that locks into the intake as described. You just squeeze the release tab on the snap in arm and pull up gently and the fuel rail and injector will come up. Usually if you just loosen the few injectors near the EGR valve it will give enough play in the fuel rail to lift it up slightly to clear the bolt.


The EGR valve is held down by two stud headed bolts. You see a nut on the fuel line bracket when you look at the EGR valve base. Take the nut off, loosen the injectors/fuel rail at the snap in mount and lift the assembly up slightly to clear the stud headed bolt. Then take the bolts out and remove the EGR.

You'll have to remove the silver top cover to access all this. It is held down by 4 plastic acorn nuts. Remove those and lift the cover off. The intake is immediately beneath it.

clay
01-27-04, 12:26 PM
Thanks for the reply....very valuable info. for a weekend warrior trying to save some money and have some personal satisfaction by doing it myself. I had the top silver cover off already and can see the large black plastic molded piece covering the rest of the top. Do I have to remove the black plastic piece to get to the clips?

Sometimes I feel so undereducated in the "right" places,

-Clay

BeelzeBob
01-27-04, 03:56 PM
That large black plastic molded piece IS the intake. No, you don't want to remove it. Just look along the side of the manifold where the fuel rail and injectors are. You should be able to find 4 injectors per side with two wires connected to each injector. The plastic "pod" that the injector mounts in is what clips to the detail of the intake manifold. You can press the locking tab to unhook the barb and pull up and the injector will just pop up with the fuel rail. Doing this to a couple of injectors near the EGR valve should provide enough "give" in the fuel rail to allow the removal of the EGR.

ellisss
01-28-04, 01:37 AM
Wow, I should have come back sooner. I would have if I had known that you would be here. :rolleyes:

(I said)
:histeric: Current Northstar engineer? :histeric:

Oh, puh-leeze. Some of those guys take 30 minutes to tie their own shoe laces. Ellisss.

(/end of what I said)


That's why I wear cowboy boots all the time....so I don't have to tie my shoelaces....LOL
Even better would be to delegate the menial task of shoelace tying to an underling. Are you an important enough 'engineer' so that you get a few gophers? :canttalk:


Ellisss....you are truely a piece of work with some of your ranting. Why don't you come on up here to Detroit and help us poor Northstar engineers out and roll away the stone for us so we can see the light. We could use a good laugh.
Oh, and of course I didn't bring-up any valid points... right?

Would you trouble yourself in an effort to pacify me, and answer a couple of questions?

1. Can you explain the relationship between mechanical valve overlap (as it occurs in any engine's valvetrain) and an EGR valve?

2. What was the reason/excuse/thinking behind the pooch-screwing idea not to solder low voltage data lines at the ABS module harness connector? What did that cause, and what were the consequences? Also, why was this SNAFU not corrected in anything that could be considered a decent amount of time?

3. What is the reason/excuse/thinking behind putting soldered splices that were only protected by electrical tape underneath the carpeting and jute near the driver's side front floorboard? (bonus points if you can name the components that were on that particular harness (hint: there's a sensor mounted under the rear seat on the driver's side) and the name of the bus that handles the communication.)

4. Can you explain the theory behind time-based and angular-based crankshaft rotation detection, and note any advantages and/or disadvantages over other methods? (please don't copy verbatim from SI2000.)


... the shaft of the valve will still build some deposits that look more like varnish than carbon or coke. THAT is what is happening to the valve over high miles. The shaft starts to get sticky in the seal and the code for EGR pintle position sets. Cleaning just the shaft of the EGR valve inside the cast in passage in the base will solve the problem.
Now, this (in my opinion) is the problem with many engineers. Your statement above shows a huge lack of real-word and in-field experience.

First, the material that builds-up near the EGR valve's pintle (or it's seat) is practically the same stuff that accumulates anywhere else top-engine. It's chemical composition is nearly identical, with the minor differences being caused by basic principals of physics.

Second, while you are correct about the contamination being caused primarily by delta temp, you are way off on the rest. Out of the scores of EGR valves I've removed, I can only remember one that was stuck closed... and that one wasn't because of a dirty EGR pintle shaft. The hard carbon that forms on the pintle's face can cause the valve to stick open.

Oh, hey, while we're on the subject... why in the world didn't some know-it-all engineer *fix* the EGR valve-building-up-carbon-and-sticking-open issue in software? Simply command the valve open between 5% and 20% (or thereabouts) for a few minutes while cruising? Sure, there would be a tiny performance drop, but it would clean the valve's seat and pintle. Heck, there could be a cool little note on the DIC... something like "EGR valve cleaning in progress..."

--
Ellisss

clay
01-28-04, 10:16 AM
Back to the original topic for just a moment...thanks for the detailed info. I am going try to take a look at it tonight and see if I can get that fuel rail holding plate off that bolt.



Thanks,



-Clay

zonie77
01-28-04, 12:11 PM
Elliss,
Regarding opening the EGR to clean it: It's my understanding that's what Chevy did on the S10's to fix their EGR problem. It opens totally when cranking to drop any chunks of carbon out.

BeelzeBob
01-28-04, 12:44 PM
Ellisss...I really don't want to get into a flaming argument here...there is just no point in it.

I don't have to have underlings tie my shoes...I told you, I wear cowboy boots so there are no laces to tie....LOL

Engineers and service techs each work in their own environment and each see the strengths and weaknesses in each others performance. For every questionable engineering situation you see I see service techs replacing 5 different parts to shotgun a problem...or cause more problems than they solve by poor service procedures and not followint the recommended service procedures...or trying to re-engineer the car instead of just diagnosing and fixing. There are obviously good techs and engineers and questionable ones....just like there are good doctors and lawyers and house builders...and questionable ones like the doctor that misdiagnosed my wife and almost killed her. I don't catagorize all doctors as incompetent becuase of that.....

I do have a fair amount of "field" experience actually, having worked on a number of service issues at different dealers. I also did several large scale field engine teardown analyses including the engineering and validation of the 4.1/4.5/4.9 re-man engine process...so I saw a LOT of dirty parts. Probably more dirty internal engine parts that most techs will see in their lifetime. Every week I review 12 to 15 torndown field return engines for analysis and complete the root cause analysis of each.

BTW...no shot at service techs but out of 10 field return engines at least 6 or 7 are misdiagnosed by the tech as to what the problem was....there is a severe lack of knowldgable techs on some of these jobs. I have seen 3 Northstar engines returned so far for "incurable oil leaks"...and all 3 were the power steering reservoir leaking into the valley of the engine...not that the power steering leak is OK...but...to R&R an engine because of a power steering leak (and not once but 3 different times) is pretty lame !!!! LOL

If you are seriously interested in the answers to your questions I can probably shed some light on them...but if you have a hidden agenda in the questions just spit it out. I really don't want to get into playing games.

I'm an engine and powertrain sort so I really can't comment on the ABS connections that you discussed....because I really don't know about them. I do know, that in some past projects, properly crimped wire connectors were desireable to soldered connectors. The problem usually rises if the connectors are not crimped properly due to worn tooling at the crimper or something. Possibly that was the problem in that case.

BTW....yes you brought up some valid points...but....you also have presented some erroneous info...and what valid points you bring up tend to get lost in your retoric regarding "those stupid engineers...". Just get the chip off your shoulder and realize that everyone has a job ot do and that the engineers do a pretty solid job of engineering and developing the carts correctly. Besides, if it weren't for stupid engineers and mistakes you wouldn't have a job, right?? LOL LOL Lighten up on the engineers and I'll try and forgive the techs that make bone headed mistakes.

The field techs have the inherent advantage of hindsight. By the time the field sees a "problem" the design was done years ago and tested and validated. Many times the engineers involved are working on another car project by the time the problem surfaces, particularily if it happens several years after the car is produced. Keep this in mind. Many times the engineers have the same reaction you voice when they look at something that happened in the field....but the cows are out of the barn at that point.

Incidentally, there are many many "low voltage" connections throughout the car that are handled daily with crimped connections at the terminals. If there was a problem at a specific location it really tends to point towards the process of crimping the connections at that connector being out of whack rather than to point towards an engineering decission to not solder the connections. True, soldering in the field is the correct repair of such a connection but the OEM crimped terminal should be fine if it is done correctly. The crimps at the PCM connections and at the other end of the ABS wire in question works OK ??? so it isn't the crimp per se. It just wasn't done correctly. That is admittedly a quality control issue..not an engineering issue.

To explore the issue of valve overlap, exhaust valve timing, EGR, etc. as they relate to each other it is important to understand that what is in the chamber when the spark plug fires is what is of concern. There is always some combustable mixture (fuel and oxygen/air) , the Nitrogen in the atmosphere that goes thru engtine and some inert material. The inert material is previously combusted gases. The inert material tends to dilute the combustable material and is therefore often referred to as a diluent. The source of the diluent can be residual exhaust gas that stayed in the chamber, exhaust gas that was sucked back in at exhaust valve closing or EGR supplied by the EGR system. Under many engine operating conditions a high level of diluent is necessary/desireable to control combustion temperatures and pressures for NOx formation control AND to improve fuel economy by reducing pumping losses in the engine. By throttling the engine with EGR the pumping losses are reduced as the engine can operate at a controlled power level at high manifold pressures. Usuallly, there is not enough diluent in the chamber due to inherent recirc...so...more diluent is supplied via the external EGR system. BTW...exhaust gas is just a convenient diluent or inert material. The same thing could be accompllished with a number of other compounds...but...exhaust gas is abundant and free. A cam shaft profile that has a lot of overlap will inherently have a lot of internal recirc due to the late closing of the exhaust valve. The recirc, or inherent "EGR" is not due specifically because of "overlap" but due to the late closing of the exhaust valve...the valve is help open late to allow complete clearing of the chamber at high RPM and if the cam timing is fixed then this ends up creating a cam with high overlap due to the fact that the intake is opening early for the same performance reasons. So...the late closing of the exhaust gives the inherent EGR...not the specific fact that there is a lot of "overlap" in the cam timing per se. In other words, it is entirely feasible to have the late exhaust opening WITHOUT the overlap and the internal recirc EGR fraction would still be high. This is the fundamental behind the VVT mechanism as it is used to reduce engine out emissions and eliminate the external EGR system. When high diluent levels are required for economy and emissions control the exhaust cam timing can be delayed to allow the exhaust valve to close late and pull inert exhaust gas back into the cylinder. With a DOHC engine and four cam VVT the intake cam timing can be retarded at the same time and purposefully ELIMINATE the recirc to keep the engine operation smooth. If you notice, in a typical pushrod engine with a single cam and fixed overlap the engine will idle rough....that "cammy" lumpy idle that is perceived as good forperformance...that is because the late exhaust event allows a lot of recirc at idle causing the rough idle. With a DOHC engine with VVT (and variable overlap) the engine can run with a LOT of overlap at low RPMS and still have good torque and smooth operation. It isn't the overlap...it is the timing of the exhaust valve event.

See the next post for the rest of the story.....LOL Too long to post in one.

BeelzeBob
01-28-04, 12:45 PM
As far the the time and angle based argument. Is there a more specific question regarding it?? Most systems that use toothed wheel pickups for RPM information and spark and fuel delivery systems use both in some fashion. The basic idea is that the teeth are in a known position that the PCM can recognize as the crank turns and thus decipher crank position. The RPM is always calculated by counting a number of teeth within a time or timing between the teeth so calculate RPM on a real time basis. In regards to spark and fuel delivery the decision as to when to fire the spark is made based on looking at a known "tooth" for an angle decision and then timing from there based on the RPM to decide exactly when to fire the spark. The issues are how many teeth on the wheel and how accurately can the "timing off the last tooth" be. More on this in a minit. The number of teeth always seems to be "more is better" for better resolution. Unfortunately, this is not always the best as there is an inherent sine wave pattern on the tooth feedback due to the crank speeding up and slowing down each time a cylinder fires and one compresses. This is minute but visible easily and can really casue havoc with the comuter calculations due to the rapid rate the data is used. If the PCM used an RPM based on timing between each tooth and there are a lot of teeth the RPM calculation would be constantly in error as it woudl pick up the speeding up/slowing down of the crank. So...it has to be filtered heavily to account for this. As far as timing off the last tooth...the issue here is the fact that if there are few teeth the timing off the last tooth accounts for a relatively long event in terms of crank shaft degrees. If the RPM changes in this time period then the "timed" event that was kicked off on the last tooth will be seriously in error. To prevent this, most events are delivered in fashion the counts teeth and then times/delivers off the last tooth to minimize the error if the RPM changes instantly. There is usually some sort of default mode that says that "if the computer is timing for an event" and the next tooth (unexpectedly) comes along due to an RPM change then the event is deliverd in a default timing to minimize the error.

Hope this makes sense. Bottom line is that there is no panacea in terms of angle based or time based systems. Both have advantages and shortcomings depending on the operating condition. Given a specific application one or the other might be practical and give good results but for an OEM system that has to be accurate over a wide operating range of RPM both are generally used within the complete operating system I would say. Suffice to say that there could be a book written on angle and time based systems and I cannot really do it justice in a short (or long) e-mail.

I have no idea about what was under the carpet....LOL Wasn't the engine I know.

You mention EGR valves....there are a lot of different types and applications of EGR valves. Some are vacuum operated such as the backpressure valves used on the 4.1/4.5/4.9 and the electronic ones on the Northstar. Which ones are you talking about. It is certainly possible to have apiece of carbon on the pintle valve causing a problem just as there can be a sticking shaft due to deposits. From what I've seen (and I've seen a lot of returned and used EGR valves) the pintle sticking due to shaft deposits is the more common issue. Since "cleaning" usually cleans this deposit off as well as the pintle it is often hard to diagnose in hindsight. I have conversed with a LOT of owners that get the "pintle out of position" code on a Northstar and they are cured 100% with cleaning the shaft inside the passage.

If you are talking about EGR and EGR codes on the 4.1/4.5/4.9 then the usual failure mode causing an EGR code is the EGR tubes in the manifold being plugged.

I don't see that there is a severe EGR problem on the Northstar or the 4.1/4.5/4.9. Systems on both cars usually easily go 100K with no EGR service required. At that point, 90% of the codes will be cured by simple cleaning 0f the EGR tubes or the EGR valve shaft depending on whether it is a 4.x or Northstar. Possibly I'm putting my head in the sand but based on field reports, warranty info and internet traffic I believe this to be true.

There actually is EGR "self cleaning" actuation that you obviously don't know about..... It must work pretty good if most all of the valves go 100K or more without sticking and the ones that do stick can be "fixed" with an easy cleaning.

I will admit to a lack of "field experience" . Can't do this job and yours at the same time. I doubt, though, that most field service techs could march into product engineering and make much of a dent in engineering new vehicles. The jobs are different and the best thing that a service tech can do is to learn as much about the production systems so that any problems can be properly diagnosed so that the feed back from the field is accurate. Unfortunately, at the moment, it isn't we have found.

Maybe there should be a thread devoted to these topics to go into more detail on some of the technical issues. The better the understanding of those on both sides of the fence the better.

ellisss
01-30-04, 01:43 AM
Elliss,
Regarding opening the EGR to clean it: It's my understanding that's what Chevy did on the S10's to fix their EGR problem. It opens totally when cranking to drop any chunks of carbon out.
Yes, but unfortunately, that does absolutely nothing for the baked-on carbon that is left on the pintle. Fixing the problem by commanding the valve to open a certain amount (for a specific amount of time, based on driving circumstances) while cruising would superheat the pintle and pulverize the deposits.

Believe it or not, GM fixes quite a number of problems by changing or updating software.
--
Ellisss.

ellisss
01-30-04, 03:04 AM
Ellisss...I really don't want to get into a flaming argument here...there is just no point in it.
Funny, that isn't the impression I get when reading some of your initial replies to some of my posts.



Engineers and service techs each work in their own environment and each see the strengths and weaknesses in each others performance. For every questionable engineering situation you see I see service techs replacing 5 different parts to shotgun a problem...or cause more problems than they solve by poor service procedures and not followint the recommended service procedures...or trying to re-engineer the car instead of just diagnosing and fixing.
How many more engineers than certified (on paper) Cadillac technicians are there? Your 1:5 ratio is bogus. You, just like your friend LoganDiagnostic, stereotype most or all dealership technicians as incompetent.

In my most humble (and admittedly sarcastic) opinion, you guys just designed it and rolled it out the door. The diagnostics, which are GM proprietary, are built from governmentally mandated standards. If I had a single dollar for every time some goofball at technical assistance tried to lead me down the wrong road, I'd have a couple of hundred bucks... and do I need to remind you where those guys get their procedures from? Some of them wouldn't know how to define the terms 'root' and 'cause' with both hands and a dictionary.


There are obviously good techs and engineers and questionable ones....just like there are good doctors and lawyers and house builders...and questionable ones like the doctor that misdiagnosed my wife and almost killed her. I don't catagorize all doctors as incompetent becuase of that.....
Oh. You don't? :disappoin

(hmmm. so this is what it's like to be speechless.)


BTW...no shot at service techs but out of 10 field return engines at least 6 or 7 are misdiagnosed by the tech as to what the problem was....
Agreed. Oh, and no shot at engineers, but:

--Most techs know the difference between a Bendix (which in actuality is only on old Ford starters), a starter solenoid, and a starter relay.
http://cadillacforums.com/forums/showpost.php?p=58528&postcount=6


there is a severe lack of knowldgable techs on some of these jobs.
Again, I'll agree with you... but only up to a point...


I have seen 3 Northstar engines returned so far for "incurable oil leaks"...and all 3 were the power steering reservoir leaking into the valley of the engine...not that the power steering leak is OK...but...to R&R an engine because of a power steering leak (and not once but 3 different times) is pretty lame !!!! LOL
Well, LOL to you too. A technician who can't tell the difference between motor oil and power steering fluid should be shot.

I find it hilarious that some overpaid engineer can design an ABS system that goes through multiple years of production without soldering terminals for low voltage data lines on the harness. That isn't a QC problem... it's a design problem. An engineering problem.

What about seam leaks on the crankcase? An explanation I got from one particular field engineer was that there was an assembly problem that was the cause... and he was serious. (Actually, he was seriously wrong.) The oil pan and manifold gets a full, solid seal... but the lower crankcase gets a partial one... by design. The powerplant falls victim to the inherent property of expansion and contraction due to temperature changes... and the seam leaks. There was no RTVS engineered into the process, which would have made the problem a fraction of what it was. For almost 10 years of Northstar production, the lower crankcase seals remain unchanged... as did the procedures used for sealing. Qualified techs (like myself) and customers who purchased 40-50 thousand dollar vehicles were forced to deal with this paticular design flaw. How easy would it have been for some proper sealant (or better side-rail seals) to have been engineered into the production process? I'm not an engineer, and yet that is but one of the problems I could have fixed myself. Another point... the factory procedure for resealing the Northstar crankcase is another design error. I made my own repairs using the factory (engineer) info as a starting point... and not a single one of the reseal jobs I did ever came back.


If you are seriously interested in the answers to your questions I can probably shed some light on them...but if you have a hidden agenda in the questions just spit it out. I really don't want to get into playing games.
No games. I wanted you to answer 'off the cuff' ... and you did. I consider myself pacified, and :worship: to your well-worded, comprehensive, informative, and easily-read answers.

Hell, at least you didn't ask me if I know what a Tech2 is.


Just get the chip off your shoulder and realize that everyone has a job ot do and that the engineers do a pretty solid job of engineering and developing the carts correctly.
No, I'm sorry... but I won't. The only thing that's obvious to me (aside from your good nature and technical expertise), is that the company and it's engineers do entirely too much tap-dancing when confronted with, well... with the things I've confronted you with. Basic principals of physics and electronics blatently ignored. Design problems that make it to assembly year after year after year... with no explanation to either customers or loyal technicians as to why these problems aren't addressed.

Damn. If the Northstar wasn't such a good design... it would have failed miserably. It continues to flourish and grow it's customer-base wholly due to it's excellent performance, and in spite of the roadblocks put in its way by GM.


Besides, if it weren't for stupid engineers and mistakes you wouldn't have a job, right?? LOL LOL Lighten up on the engineers and I'll try and forgive the techs that make bone headed mistakes.
Okay. Point taken, Mr. Engineer. :)


Incidentally, there are many many "low voltage" connections throughout the car that are handled daily with crimped connections at the terminals.
Oh, brother... just when I was starting to like you. :bighead:

A low DC voltage signal is extremely persistent, and handles noise induced by various SNAFUs quite easily. ::cough:: A low ac voltage data signal will become useless with the slightest amount of induced noise. My whole point on the unsolderd ABS module data lines is that it happened (which was no big deal)... and then it was recognized... and then it was allowed to propogate through many, many years of production. New systems and sub-systems were designed and implemented, and some old ones were updated... but the unsoldered, low-voltage data lines were allowed to remain. I couldn't, if I tried really really hard, tell you how many ABS module harnesses I had to repair because of this.



If there was a problem at a specific location it really tends to point towards the process of crimping the connections at that connector being out of whack rather than to point towards an engineering decission to not solder the connections. True, soldering in the field is the correct repair of such a connection but the OEM crimped terminal should be fine if it is done correctly.
No, I do not believe you are correct... and since you have admitted that you're more mechanical than electrical, I'll have to insist that you are mistaken. For three years straight the yaw sensor signal line was spliced under the floorboard, near the driver's side seat. This splice was protected by nothing but a thin layer of that goofy, sticky tape (it pisses me off too much to call it plain-old vinyl tape). Water, sand, movement, and time all played their parts... and nobody but the technicians had to deal with it.

It is blatent absurdity for anyone, especially an engineer, to say that a line carrying low voltage data signals doesn't need soldered connections. Gee whiz... the ABS module is under the car, exposed to the elements. Do you really think solder isn't (or wouldn't be) necessary?

Anyway, thank you for taking the time to type so much.

--
Ellisss.

BeelzeBob
01-30-04, 12:02 PM
Elliss...let's agree to disagree rather than argue...much more constructive and we can both learn something maybe....

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How many more engineers than certified (on paper) Cadillac technicians are there? Your 1:5 ratio is bogus.

You need to reread my commnent I think. There was no 1:5 ratio that I mentioned. I said I see techs replacing 5 parts to fix one problem. It happens.. a LOT. Our warranty data proves it. Same car, same day, 5 different parts replaced.....just shot gunning.

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--Most techs know the difference between a Bendix (which in actuality is only on old Ford starters), a starter solenoid, and a starter relay.
http://cadillacforums.com/forums/showpost.php?p=58528&postcount=6

You are correct in a sense. I made the mistake of using the well understood slang "Bendix" expression much like I call all circular saws "Skil' saws....LOL I KNOW you never do anything like that so I will be more careful in the future. I think you knew what I was talking about so I will take your comment with a large grain of salt. LOL Next thing we'll be arguing over whether it is a generator or an alternator.....or whether is is an engine or a motor.....

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It is blatent absurdity for anyone, especially an engineer, to say that a line carrying low voltage data signals doesn't need soldered connections.

That is strictly your opinion....but....there are thousands of non-soldered , crimped connections in every car carrying VERY low voltage signals and they function fine. I am sure that there are many opportunities to pick apart certain design and manufacturing aspects of cars...any and everybodies cars. After seeing one or two of a problem the attitude tends to become "they all do that..." when, in fact, there are thousands running fine for everyone that fails. They do not ALL do that. And that applies to electrical and mechanical problems alike.

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I realize that you are an "experienced" tech with 5 years of Cadillac experience under your belt I think?? I have been working for GM for 32 years strictly in the engineering area with forays into field problem resolution, manufacturing plant Resident Engineer experience, etc... There is some additional insight gained by seeing different systems come and go in production rather than just learn about the Northstar and make judgements.


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I will agree with you that the Northstar case half seal has been trouble some. That is a very difficult to seal joint due to the loads carried across the joint, the thermal expansion/contraction, the interface of the side seals and the front and rear main seals, etc... There is no "single" problem with that joint as is oft implied. The joint is actually performing reasonably well over the long haul. It will seep on older engines but rarely gets to the drip stage in my experience. I have seen a lot of lower crankcase "reseal" jobs done unnecessarily because the real culprit was an oil filter adapter seal or an oil cooler line seal/fitting that was misdiagnosed. I also come across many many owners who never even knew that the joint was seeping until a tech/mechanic pulled them under the car and pointed out the "Horrible" oil leak they had and then charged them $2000 or better to fix it....when it was a completely benign condition that was not hurting a thing. Not to excuse the seepage as it is the subject of ongoing engineering scrutinty to totally prevent on 100% of the cars...but It is rather irritating to hear of the number of people buying a 10 year old car and then crying about a greasy engine and the infamous "case half leaks" that are being dramatically overblown...in my opinion. If it is not dripping on the ground, and few case halfs leak this badly, then is it really such a big issue?? The case half seal will never fail catostropically and will not creat a walk home. So why worry about it on a 100K, 10 year old used car which is often the subject.

I think it is important to properly identify root cause of any oil leak . An oil leak on a new engine is obviously not acceptable and needs to be repaired. If it is the "case half" then there is some assignable casue as the seals will not leak if the parts are manufactured correctly and the seals installed correctly. Our testing proves it.

clay
02-04-04, 09:22 AM
Well, I got the valve off, though I started getting very uncomfortable with just how much pressure I had to put on the fuel lines to get them out of the way for me to get a socket on the shared bolt. I used a screw driver to lever the plate away with my other hand. And this is after unseating 7 of the injectors. Am I missing some other item that could be loosened up?


In looking at the valve, there is a lot of black residue throughout and it sticks very tightly in the closed position. I really need to push it hard in order to open it back up after it springs shut. I cleaned it, but am not happy with the results and am leaning towards purchasing a new one, since it is already off and it is such a pain to get to this point. The car only has 50k, but it was all short trips in the city, so I'm guessing I have more carbon build up than normal due to this.

Thanks for the help...is there another bolt to loosen to make this easier to go back in?

Thanks,

-Clay

BeelzeBob
02-04-04, 12:30 PM
Well, I got the valve off, though I started getting very uncomfortable with just how much pressure I had to put on the fuel lines to get them out of the way for me to get a socket on the shared bolt. I used a screw driver to lever the plate away with my other hand. And this is after unseating 7 of the injectors. Am I missing some other item that could be loosened up?


In looking at the valve, there is a lot of black residue throughout and it sticks very tightly in the closed position. I really need to push it hard in order to open it back up after it springs shut. I cleaned it, but am not happy with the results and am leaning towards purchasing a new one, since it is already off and it is such a pain to get to this point. The car only has 50k, but it was all short trips in the city, so I'm guessing I have more carbon build up than normal due to this.

Thanks for the help...is there another bolt to loosen to make this easier to go back in?

Thanks,

-Clay


If you really want to buy a new one then be my guest, but, cleaning it really is all that is required in 90% of the cases that I see.

If you unclip the fuel rail/injector pods at the injector (from the intake - press the barbed clip connection to unlock it and the pod will slide up with little or no force) the entire fuel rail will move upwards to allow the clearance. You shouldn't have to use that much force.


Hold the EGR valve right side up so that solvent will NOT run down the shaft into the can and flush the passage with solvent from a spray can (carb cleaner type of solvent) while you work the pintle with you ringer to free it up. If it is sticking then it is because of the deposits on the shaft that the pintle valve is mounted on. The deposits on the shaft cause a loss of clearance in the shaft clearance hole above and it will stick. Clean the deposits off the shaft up inside the cast passage inside the base and it will free up and be fine.

TexasAxMan
05-23-05, 04:57 PM
This is probably the most entertaining thread I've seen so far. But then again, I'm a new member......

w00k1e
05-23-05, 08:04 PM
a really really quick question, i'm a complete novice here and i was just wondering what the symptoms of a dirty EGR valve are? My car is showing the code for it, and on cold starts it takes a couple seconds of cranking before it starts... is the EGR to blame? or a bigger problem? (its a 96 Deville)

a very entertaining read by the way! heh

BeelzeBob
05-23-05, 08:16 PM
Geez...who dredged this thread up....???....LOL

If you think this is intertaining you must have missed the exchange with gmt2U in another thread recently.


If the EGR code 36 is showing up it means the EGR valve is not moving the pintle shaft according to the commands from the PCM. Take the EGR valve off and clean the SHAFT of the valve up inside the passage in the base of the valve. Deposits on the pintle valve itself are not usually a problem. Deposits on the shaft cause the shaft to stick eventually inside the clearance hole in the base of the valve. Just cleaning the shaft of the valve is usually sufficient to correct the problem.

Unless the EGR valve was sticking open all the time I wouldn't expect it to cause hard starting.

Have you checked the fuel pressure regulator? With the engine idling, remove the vacuum line from the FPR and watch the vacuum nipple on the FPR for any signs of fuel leakage. There should be none. The FPR is the small, canister shaped device on the fuel rail. It has a vacuum line attached to it on one side and the fuel return line on the other....and the fuel rail running thru the middle of it.

BodybyFisher
06-09-05, 01:41 PM
Man I hate this type of confrontation. Thickheadedness and stuborness in the face of facts and other people's experience is extremely frustrating. Logan I have never seen you so talkative! Mike (Scotty) :)

I popped in here to see how this board is and came across this..... I think I will crawl back into the woodwork again....:)