: Using oil....but where?



mwurden
02-25-05, 03:42 PM
Hi there. I bought a '96 Seville STS a few months ago. Car only had 54k miles on it (verified by CarFax). Put about 10k on it so far, and it is using a lot of oil....about 1 qt. every 350 miles. Car was sitting for some months before I bought it. Checked compression, it seems good...about 110 all around (read 90-91, mechanic said his guage was off by about 20). Does have a slight oil pan leak....not enough for the usage I'm seeing. I'm not sure what else I should be checking. Thoughts?

Thanks in advance,
Mark

zonie77
02-25-05, 09:34 PM
The rings may be gummed up and sticking in the piston grooves...not putting tension against the walls.

Some WOT runs should help. There is a procedure to clean them by putting solvent in all the cylinders and letting it sit, removing it, then changing the oil. Look for threads about that. It is an official Cadillac procedure.

Ranger
02-25-05, 10:47 PM
Go to the home page http://www.cadillacforumsorums.com. Click on technical archive in the upper left corner and read up on oil consumption. It's perfectly normal and once you understand it, you won't worry about it or consider it a problem. It was written by a GM engineer.

Spyder
02-26-05, 02:50 AM
A quart in 350 miles is a bit much though...try the 'ol WOT blasts and see if that helps out any...put her in second gear and put your foot to the floor until you shift just past 80...then let it coast back down...lots of black smoke is gonna come out the exhaust the first dozen or so times, but it'll clean up real quick and with any luck, oil consumption will go down quite a bit. Read up on this forum about the oil and anything else you're interested in. Welcome aboard!

mwurden
02-27-05, 11:49 PM
The rings may be gummed up and sticking in the piston grooves...not putting tension against the walls.

Some WOT runs should help. There is a procedure to clean them by putting solvent in all the cylinders and letting it sit, removing it, then changing the oil. Look for threads about that. It is an official Cadillac procedure.

Thought about that. Ran some off-the shelf solvent through it....not much effect. Cadillac shop does have a procedure for sticky rings....$600. Worth it if it fixes it....waste of money if it doesn't. Car was sitting for some months before I bought it...so sticky rings sounds very possible. Wouldn't that show up on the compression tests, though?

Can always do some more WOT runs....that's not a problem at all :coolgleam

zonie77
02-28-05, 09:43 AM
The first thing is to determine if you are leaking it or loosing it through the exhaust. The leak detection would be visible. Clean cardboard under the engine everytime you park it...then follow up what may be leaking. A pressurized fitting may leak a lot when it's running but only a few drops when shut off. Seeing a small amount on the cardboard and dismissing it without checking what's leaking could waste a lot of time and energy.

That compression reading is a little low but one MAJOR problem is a mechanic who's gauge is off by "20 lbs". Compression gauges are relatively cheap, NO excuse to use a defective one. Plus how does he know how much it's off? I wouldn't trust that gauge or the mechanics diagnostics. Learn to do it yourself.

What type of solvent did you use? Oil based additives can take hundreds or thousands of miles to work. Fresh oil has a pretty strong detergent package so a couple of changes at short intervals might help. That would be a good idea with solvent added anyway to remove any sludge being broken loose.

If you read the Cadillac procedure you see it's something you could do at home. It isn't that hard.

CadillacJack76
03-01-05, 06:25 PM
My 98 Eldo had a similar problem, it would use oil but I would never see it leaking, and it wasnt going out the tailpipes. It was losing about 2 quarts a month, I took it back and forth to the dealership so many times I can't even tell you, and they would say " Oh thats normal for a Northstar to use oil" Let me tell you, thats the wrong answer, if you spend 40,000 dollars on a car, it had better not be using any oil. Anyway, I was coming up on the end of my warrantee, so I took it back to Cadillac, and complained yet again, the idiot told me that he had the car on the rack and saw some "seepage" around the oil pan, and it wasnt leaking. ???? I asked him what the hell he was talking about, because usually you define an oil leak as oil on the outside of the engine, right? So if you see it on the outside of the engine it has to be leaking from the inside?? The tech told me " no I said seepage not leakage" I blew my top, told him to get my f-ing car off the lift and I will bring it to a real Cadillac dealership. Well, at the time I was in Norfolk Virginia, my normal dealership is in NY, so I came back to NY with the car and brought it to King O'Rourke Cadillac and they had the car up on the rack for about ten minutes before they found the leak. Great, right? Nope, my warrantee had expired. but since I had documentation of this leak with Cadillac for years, they picked up the check and fixed it. So, you wanna know what was leaking? The rear seal on the block was leaking oil into the tranny bellhousing and the heat from the engine was burning it off before it managed to leak out, by the way, there is a TSB from GM on it. So next time someone tells you that it is normal for a northstar to piss oil out, tell em bout my story. Wow, that was a long story.

Jack

david1549
03-02-05, 05:32 PM
I've got to get into this!!!
I agree with most everything in all the replies here, but.............
It's a Cadillac, it cost a lot of money when it was new and costs a lot even as a used car. It shouldn't leak, seep or burn oil with anything less than 150,000 miles on it.
I bought a '96 Seville SLS with 89,000 miles on it back in September of '04. A firm believer in frequent oil changes, my first trip was to my friend and mechanic at the local Exxon station in Billings, Montana where I was living. He'd done some work for me in the past and felt he was more than qualified to advise me as to what was best for my car. He completed the task and said keep an eye on the oil level as it has some leaks. My reply was bullshit!, I've got a extended warranty with the car and I think that kind of stuff was covered. It was and he, as a certified shop was qualified to do the work to completely reseal the engine. The job was completed to my satisfaction and I picked the car up a week later. It wasn't long after that I got a message on the car's reader board to "check oil level" and I stopped at the Exxon station and reported the same. They checked it and reported to me that it was a half quart low and that maybe when they filled it after resealing the engine they didn't quite fill it full.
Shortly there after we moved to our present location in north central Washington State. My beloved Seville burned, consumed or otherwise used a quart of oil in 800 miles. I chalked it up to pulling a small trailer, the smallest U-Haul has, but was seething inside. A month and less than 500 miles later, I got the same message on the reader board, "check oil level" and added another quart of oil.
I lost a leg in '90, but used to do all of my own work including oil changes. I used Penz-Oil in all my rolling iron from the cars, trucks, lawn mowers, garden tractor, air compressor, etc. I'm 59 years old, owned a bunch old and some new cars and trucks, I've seen miracle oil, miracle filters, miracle additives and have tried some. NOTHING so far stacks up to Penz-Oil.

I had the oil changed in the Seville in November '04 at a Quaker State place no less, It was neat and clean, but made them put in 10W30 Penz-Oil. They charged me a whole bunch extra and I'll go to a Penz-Oil place next time. It's 2500 miles later, no smoke, no oil consumption and no leaks or seeps!

mwurden
03-07-05, 04:57 PM
CadillacJack,

I think I have a similar problem...mechanic did say it was leaking "a little" around the oil pan. I'll take it to Cadillac and see if they can check the seals.

Zonie77,

Yes, I had the same thoughts about the guage. I had tried doing it myself initially, but can't find a compression tester--Autozone didn't have one, salesperson even seemed confused about what the heck a compression tester was (didn't know what one looked like--huh?). Does anyone here know what compression should be? Anyway, my take right now is that still need to check it, but that it doesn't seem off enough to explain my oil usage.

David1549,

Ok, this is too small a world. I grew up in Billings, and then moved over to Washington myself (currently in Texas). Where were you in Billings? Anyway...I haven't tried the Pennzoil yet. FYI: Pennzoil is different than other oils...it has a lot more parafin in it. Originally formulated that way for race cars...particularly Indy 500. So, Pennzoil does indeed outperform other oil...but it does break down faster. Something to keep in mind (it was originally designed for, you guessed it.....500 miles of usage)..

All...the additives I put in were some Restore. Can't remember which solvent....added it and ran for a few minutes before changing the oil. Have also been putting in an additive with every quart lately....basically a conditioner and viscosity thickener.

UPDATE: Oil usage is down now....maybe about 1 qt every 700 miles or so. So, making progress! Think either the Restore is taking effect, or the additive is helping (at least to control oil leakage/burning).

Also, FWIW---car doesn't seem to smoke at all, even at WOT, and no oil buildup on plugs. So, that seal leak is starting to sound like the culprit...would just like to nail down expected compression range. I don't mind adding the oil...just trying to see if I'm having a performance/longevity effect.

david1549
03-07-05, 06:08 PM
'Tis indeed a small world, I lived in Armadillo for a while (for you spell checkers we Texans know this is misspelled, but know where it is).
Anyway, I had all my work done in Billings at Corridor Exxon on 27th + 9th street, I lived just a short distance away at the time. I had them completely remove and reseal the engine because I had an extended warranty with a $100 deductible. That turned into a $500 bill with some extras, new belt, belt tensioner, oil sensor, etc. I happily paid and got on with life. Shortly after my new oil sensor went on, telling me to check engine oil, I was close so I pulled into the station and had them check the oil. It was a quart low and was explained away by saying maybe they didn't quite fill it when they put the engine back in after the reseal, it takes 71/2 quarts you know, they exclaimed.
We move to our present location shortly after, it burned another quart in 700 miles and another about 400 miles later. I had the oil changed at a Pennzoil place and I'm at the 2500 mile mark, no oil usage and no smoke.
I'm 59 years old, seen a lot of those "mechanic in a can" oil additives, tried some myself. I've used all kind of brand name of oil and keep coming back to Pennzoil.
We can talk at length about oil and you can email me: dlarson_2@charter.net (dlarson_2@charter.net)

BeelzeBob
03-07-05, 06:46 PM
saw some "seepage" around the oil pan, and it wasnt leaking. ???? I asked him what the hell he was talking about, because usually you define an oil leak as oil on the outside of the engine, right? So if you see it on the outside of the engine it has to be leaking from the inside?? The tech told me " no I said seepage not leakage" I blew my top, told him to get my f-ing car off the lift and I will bring it to a real Cadillac dealership.

The rear seal on the block was leaking oil into the tranny bellhousing and the heat from the engine was burning it off before it managed to leak out, by the way, there is a TSB from GM on it.
Jack


Hate to get into it with you Jack...but....

There is a big difference between some seepage of oil and an oil leak. I would side with that tech on that. It is pretty rare to see anything on the underside of a car that is PERFECTLY dry. Most any car will have some evidence of oil penetrating gasketed surfaces and leaving a trace of oil. That is a seep. If it doesn't drip on the ground it is a seep. IF it is dripping and dropping then it is a leak. Sounds like you had an oil seepage just like he described it and that was obviously not a problem.

I know that a seep is oil outside the engine and that TECHNICALLY in your black and white world that would be a leak but most of us live in the real world where things are not so black and white and where small "leaks" are called oil seepage....LOL

The rear seal leak into the "trans bellhousing" and the "heat of the engine was burning the oil away before it leaked out" story is BS. May be what they told you but it doesn't pass the common sense test and there is no such service bulletine of that phenomenon. Think about it. If the "engine heat" is so great in that area to "burn the oil away" you would have seen smoke and smelled a lot of burning oil and, funny thing, that same "engine heat" is there INSIDE the engine....wonder why it doesn't "burn away" the oil inside the engine, too. They obviously wanted to get rid of you as simply as possible and you took the bait. Besides, the transmission bellhousing area drains downward cleanly to the dust cover over the torque converter and that cover has hole in it....so....any oil in that area hits the ground in about 3 seconds. There is nothing to hold or trap it so that it can "burn away" from engine heat....LOL LOL

You need to get under that and have them explain what REALLY happened. Go back to the tech that described the oil pan leak as a seep. He sounds like he knows more than the other guys.....LOL.

zonie77
03-07-05, 06:55 PM
The additive to use would be one with a lot of detergent to loosen the rings. It would take awile to work. I wouldn't add any thing that would thicken the oil (STP type) because you want it to flow easily. I think Restore is the detergent type.

AutoZone seems to have inventory problems (probably a lot of theft). They constantly show things in the computer that aren't available...esp tools that are out on the floor.

There ought to be other places to get a compression gauge.I think pressure should be in the 120-130 range. I put a lot of emphasis on the first compression stroke, rather than how high it can go with persistent cranking.

BeelzeBob
03-07-05, 06:58 PM
CadillacJack,

All...the additives I put in were some Restore. Can't remember which solvent....added it and ran for a few minutes before changing the oil. Have also been putting in an additive with every quart lately....basically a conditioner and viscosity thickener.

UPDATE: Oil usage is down now....maybe about 1 qt every 700 miles or so. So, making progress! Think either the Restore is taking effect, or the additive is helping (at least to control oil leakage/burning).

.



PLEASE PLEASE stop putting Restore and other additives into the oil. They are NOT needed and are detrimental to the engine. Amazes me that people that are so obcessive about a little oil consumption (because "something" may be wrong with my engine") will pour crap like that into their "precious" engine.

Restore is a con. Plain and simple. It is designed to relocate your money into someone elses pocket. Forget it and all other additives.

Forget any sort of additive to clean the rings from the oil pan side. Pointless.

Forget any additive that is a "viscosity improver". They are not necessary as the oil has viscosity of it's own aplenty. Viscosity isn't "improved" upon, anyway. Viscosity "improver" is a euphimism for oil THICKENER. If you want thicker oil then use it. Forget putting an additive in that thickens the oil. It it said oil "thickener" on the can you wouldn't buy it....so the "viscosity improver" bullshit took you.

Viscosity improvers are notoriously bad for causing ring belt deposits and sticking the rings in the grooves. In SHORT TERM testing they seem to help as the thicker oil is slightly less likely to get by the rings and the additive is filling nooks and crannies in the ring belt with deposits and cutting down the oil consumption.... THEN the stuff turns to tar and the rings stick permanently and the oil consumption and compression goes to hell. DO NOT USE THEM. GET THE PICTURE.??

Change the oil and get rid of all the crap you have been putting into it. Put a new AC filter on. Pour in 7.5 quarts of fresh Mobil DriveClean conventional motor oil. 10W30. Run the engine on the road until the oil is hot. Park it on a level surface and check the oil level HOT with the dipstick. It should be on the full mark when HOT with the 7.5 quarts in it. If not, remark the stick. Do NOT fill it above this point, ever.

Run the engine. Drive it. Do some WOT accels in first to the redline upshifts. Drive it on the expressway at 55 in second gear. Accel to 70 at WOT and lift off and let it decel to 55 with the engine braking. Do this 10 or 12 times per trip when you get chance. This will exercise the rings and free them up and make sure that they are seated in the ring grooves. This is the BEST thing that you can do to the rings and cylinder walls to make sure the rings are free, seated and operating fully. You should notice improved oil consumption in several thousand miles of doing this occasionally.

BeelzeBob
03-07-05, 07:06 PM
You guys really need to understand and accept that some level of oil consumption is fine and good and is there on every engine. Look at the BMW, Mercedes, Lexus, Porsche, etc.... literature. The Northstar is in with some pretty pricey company with it's "oil consumption" habit. ALL of the aforementioned competition have statements in public to the effect that oil consumption of as much as 1 quart per thousand miles is considered acceptable and is not a sign of an engine problem. All of them say this if you look. Everyone with high performance engines treads the line between enough oil consumption to keep the engine alive at continuous full throttle and little enough consumption to satisfy the customer. There is some variability in all engines and, though not designed to use 1 quart per thousand miles some will due to production tolerances, variability of the operating schedule, differenct breakin procedures, different oils, etc....

BMW had such an issue with some of their M-series engines that they said in the owners manual to check the oil level at EVERY gas stop on the autobahn as oil consumption at high load could exceed the reserve capacity in the sump for each tankful if the oil level were not topped off. And the engines are fine......they just use oil....and they cost way more than $40K.

Murphyg
03-08-05, 12:32 AM
Hate to get into it with you Jack...but....

There is a big difference between some seepage of oil and an oil leak. I would side with that tech on that. It is pretty rare to see anything on the underside of a car that is PERFECTLY dry. Most any car will have some evidence of oil penetrating gasketed surfaces and leaving a trace of oil. That is a seep. If it doesn't drip on the ground it is a seep. IF it is dripping and dropping then it is a leak. Sounds like you had an oil seepage just like he described it and that was obviously not a problem.

I know that a seep is oil outside the engine and that TECHNICALLY in your black and white world that would be a leak but most of us live in the real world where things are not so black and white and where small "leaks" are called oil seepage....LOL

The rear seal leak into the "trans bellhousing" and the "heat of the engine was burning the oil away before it leaked out" story is BS. May be what they told you but it doesn't pass the common sense test and there is no such service bulletine of that phenomenon. Think about it. If the "engine heat" is so great in that area to "burn the oil away" you would have seen smoke and smelled a lot of burning oil and, funny thing, that same "engine heat" is there INSIDE the engine....wonder why it doesn't "burn away" the oil inside the engine, too. They obviously wanted to get rid of you as simply as possible and you took the bait. Besides, the transmission bellhousing area drains downward cleanly to the dust cover over the torque converter and that cover has hole in it....so....any oil in that area hits the ground in about 3 seconds. There is nothing to hold or trap it so that it can "burn away" from engine heat....LOL LOL

You need to get under that and have them explain what REALLY happened. Go back to the tech that described the oil pan leak as a seep. He sounds like he knows more than the other guys.....LOL.

Great info Bbob
This one as well as your following posts in this thread.
As well as the pelothera of other info you have provided elsewhere.

But I would like to ask one thing of you.

Whilst providing us of your seemingly endless knowledge, would it be possible for you to refrain from your belittleing insiduios comments.

Your explanation of the difference between an oil leak and seepage as explained by a tech is good to know.

But to start your post to CadillacJack76 stating.

"Hate to get into it with you Jack...but...."

Then say

"...TECHNICALLY in your black and white world that would be a leak but most of us live in the real world where things are not so black and white ..."

He was only trying to help with what he has learened from his own experiences.
Why are you so crass and rude ???

Just cause the info he recieved from another tech was incorrect is no reason to state that he doesnt live in the real world.
What is the color of the world you live in ??
Is it always black,white,or the colors of the prism ??

As far as Im concerned; the black and white of the real world does not include intentionally insulting another individual for the simple reason that they were trying to help with information that they believed was true.

The knowledge that you share with this forum is insurmountable.
But you need to remember that this a Cadillac owners forum and not a Bbob forum.
You need to give the rest of us a break.
Ease off on the insults. Its not neccesary, and certainally not becoming of you.

mwurden
03-08-05, 01:06 PM
bbobynski,

I agree with you on the oil additives. I was using them mainly to try and determine what the problem is, not so much as a cure. You might say "accept that some level of oil consumption is fine and good and is there on every engine", but I think you would agree that if it were your car that were using a quart of oil with every tank of gas, you'd be somewhat concerned, wouldn't you? If indeed it turns out that everything else on the motor is fine, then I'll happily just keep adding the oil. At the current time, though, I am concerned that such oil usage is indeed a symptom of some issue...either a leak, stuck or worn rings, etc. If it is some internal problem, I am concerned that I am both suffering a performance problem, and also have some condition that is affecting the long term life of the motor. If consumption were more in the order of a quart every 1000 miles...I'd chalk this up to 'normal Northstar consumption.' At a quart every 350 miles....this seems pretty high. The WOT blasts don't smoke at all, AFAIK, so indications are that is not cleaning anything up. So, some sort of seal leak seems like the culprit. Which I can live with much better than any internal problem.

As to the additives, I was primarily adding the viscosity enhancer to see if it had an effect...ie, as a diagnostic, not a cure. The Restore, as stated above, is more of a detergent, so I felt it might help loosen any sticky rings/valves. Now that consumption seems to have a bit more back to normal, I'm going to pull back on those and see if it stays where its at now. Will keep everyone posted....thanks for all the great help!

ljklaiber
03-08-05, 01:20 PM
Ya'll need to really listen to Bobynski.

As I have stated before, I wail on my 95 SLS and it just gets better. As I have 148K on the engine, I use Valvoline MaxLife 10-40w and use no Synthetic.

The Northstar is a Modern Alloy bullet. If I leave .50cents on the street, I am 'sorry bout that'.

Be a Driver! :)

BeelzeBob
03-08-05, 02:44 PM
Great info Bbob
This one as well as your following posts in this thread.
As well as the pelothera of other info you have provided elsewhere.

But I would like to ask one thing of you.

Whilst providing us of your seemingly endless knowledge, would it be possible for you to refrain from your belittleing insiduios comments.

Your explanation of the difference between an oil leak and seepage as explained by a tech is good to know.

But to start your post to CadillacJack76 stating.

"Hate to get into it with you Jack...but...."

Then say

"...TECHNICALLY in your black and white world that would be a leak but most of us live in the real world where things are not so black and white ..."

He was only trying to help with what he has learened from his own experiences.
Why are you so crass and rude ???

Just cause the info he recieved from another tech was incorrect is no reason to state that he doesnt live in the real world.
What is the color of the world you live in ??
Is it always black,white,or the colors of the prism ??

As far as Im concerned; the black and white of the real world does not include intentionally insulting another individual for the simple reason that they were trying to help with information that they believed was true.

The knowledge that you share with this forum is insurmountable.
But you need to remember that this a Cadillac owners forum and not a Bbob forum.
You need to give the rest of us a break.
Ease off on the insults. Its not neccesary, and certainally not becoming of you.


Read 'jack's comments that I quoted and then read my post in that context. After mentioning that he "blew his top" and wanted to "take his car to a real Cadillac dealer" due to a level of oil seepage that the tech seemed to be vey honest about I think my statements are in order. Go back and read his original post if you think that MY post was crass and rude....LOL

Besides, anytime you question or contradict what someone says or present another view point of you tend to "get into it" with them. The whole idea of accepting that oil was leaking into the bellhousing and then being burned away by the engine heat is pretty far fetched....and needed interidiction least someone else waltz down that path.

Pretty much like everyone else on this and other forums I speak my mind. I don't intend to start saying what you want to hear. If you do not like this then there is a feature of the forum that lets you skip my posts. I would recommend that for your sensitive nature. Besides....did you not notice the little.....LOL....after my comments where I was trying to induce a litttle levity into the comments.

I realize that this is not a bbob forum but, reading the variety of posts over the past year I think I have posted more factual information and helped people solve more problems than most people. If you like the info then keep reading. You'll just have to put up with my caustic nature. I admit to being rather touchy after someof the more mundane things have been covered 20 times or more. If you cannot put up with it....then see above.

P.S...If you think I have been crass and rude....LOL....I can be REALLY crass and rude. .... just kidding. Point taken. I will try to refrain from my personal commentary in the future.

Murphyg
03-09-05, 10:09 PM
..............P.S...If you think I have been crass and rude....LOL....I can be REALLY crass and rude. .... just kidding. Point taken. I will try to refrain from my personal commentary in the future.

Thank you bbobynski :thumbsup:
Thats all that i was asking.
I can understand your frustration; having/needing/wanting to repeat info over and over, (not necesarilly in that order). LOL
Just felt I had to ask you to refrain from that kind of sarcasim.
Like you had said your self. The perception of the world comes in different shades of black and white for all.
Was hoping you could understand that some comments could be percievied in a derogative manner.
And the last thing this forum wants is to loose members because of; (for lack of another/better term); political incorrectness ? :shhh:.
Like said, "lack of a better term". :eye:

I myself will also try to follow your lead:

I will try to refrain from my personal commentary in the future.

Professionalism goes a long way.

Thanx once again for understanding.

:cheers:

slw123
03-16-05, 12:22 PM
I also have the dreaded oil consumption issue since I owned my car (99 STS 75kmi - bought it with 47k).

I've been using about a quart every 500 miles. When I step into it I find that I get some nasty smoke too - but a few minutes later it doesn't smoke when I romp on it again; so I think I will try the 2nd gear WOT to try and blow all this crap out and slow down consumption maybe.

I have found one thing tho and I wonder if anyone can comment.

The hood liner on the oil fill side seems to have absorbed quite a bit of oil - I couldn't tell you if this is recent or a slow build up as I just noticed it about a month ago.

Any ideas? Could this be a clue to a bigger problem or maybe the oil fill cap was loose or something?

Thanks!

JimD
03-16-05, 12:39 PM
....
The hood liner on the oil fill side seems to have absorbed quite a bit of oil - I couldn't tell you if this is recent or a slow build up as I just noticed it about a month ago.

Any ideas? Could this be a clue to a bigger problem or maybe the oil fill cap was loose or something?

Thanks!

If the oil is lined up directly above the serpentine belt you could be throwing a drop or two from anywhere the belt travels. Power steering pump, A/C compressor, or the cover behind the harmonic balancer. Does the belt show any signs of oil?

importdvdz
03-17-05, 02:55 AM
Mark don't worry about Oil use, Every 96 engine has that problem, it is a factory defect, My Eldo has only 75 thousand miles and takes as much oil as yours. I believe every engine this year has that problem, Car doesn't loose horsepower, it still flies as a bullet just need to keep your eyes on the oil to make sure it's full all the time.

Multi Caddi
03-17-05, 09:28 AM
bbobynski
I have tracked your advice on a number of cadillac issues and thank you greatly for your contributions, as a cadillac fan of 20 years and currently owning caddys from 50s to 90s i decided to put my money where my mouth was and was one of small number of people in UK who went and bought a new (RHD)99sts apart from being the best car i have ever driven one thing puzzle me.
The Caddy resellers in UK All put mobil 1 fully synthetic in all new STSs from day one, and subsequent lube changes, I have maintained this with all oil changes being fully synthetic, can you comment on the use of fully synth in the Northstar ?

PS did you work for Cadillac or on Northstar ? appreciate any comments

Cheers

Res STS
03-19-05, 12:29 AM
Your Northstar has problems if you only go 350 miles to a quart of oil and you only have 90 or even 110 psi compression.

My 98 STS goes about 1500-2000 miles on a quart of oil. My mini-Northstar Aurora would go 3000 miles on less that a quart of oil.

The shop manual calls for 140-170 psi cranking pressure with the throttle open, I'd expect cranking pressure should be at the high end of this for a healthy engine near sea level.

Sorry to bring bad news.

slw123
05-02-05, 09:26 AM
:eek:
99 STS 76k mi
oil usage just got worse, and i started smelling it after driving. never any in the driveway. losing about a quart every 300 miles.

took her in to the shop. the bad news -
lower crankcase half? and coolant crossover pipe is leaking....also have a tie-rod issue.

gotta drop the engine. gonna be around a $2700 job. with that much loss i assume fixing it is the right thing to do?

if i'm going into debt anyway maybe i'll have that Corsa exhaust put in...
:yup:

suck.

Ranger
05-02-05, 07:14 PM
Hard to believe the half case is loosing a qt. per 300 miles. How about the oil lines at the filter adapter?

1996deVille
05-03-05, 12:05 AM
Hey look at the bright side... at least we don't have piston slap problems with the N* engines. And, thank god we don't have RWD - I'm sure we'd have ended up with the stock CTS V unit.:histeric:

I know this much - if the problem occurs because of tolerances upon assembly, were all in trouble. There shouldn't be that much difference between two N*'s, and all the oils have to meet the same standards, so that's not the problem either.:yawn:

In my case I don't have a problem with an engine using 1 qt. per 1000 miles. But I didn't expect it upon purchasing the car. All I ask is for the dearership to be honest enough to let the customer know so were not shocked when it takes place. :vomit:

97BlueDeville
05-03-05, 03:23 AM
Talking about Oil Consumption...

I bought my 97 Deville from my father. He told me often when he owned it that he needed to add about 1 qt of oil every 800 - 1000 miles or so.. He used the recommended 10w30 or 5w30. With 135,000 miles on the clock I took the car under my wing, and love it !!! I knew with the use of a little thicker oil, the oil consumption would decrease.. So I use 15w40, also my driving habits are completely different than my fathers. I go WOT often and drive aggressive, he's taps the gas here and there, just enough to get you to the speed limit. I noticed a big difference in oil consumption on my car now after driving it a while. After 10,000 miles from me, shes now down to about 1/2 a qt in 800 miles VS a full Qt. That's the positive, the negative is due to my aggressive nature on the throttle, that probably lead to a earlier HEADGASKET failure than if my father would have kept driving it around. Oh it still would have failed, that's for sure. But with my heavy foot often it lead to it earlier, perhaps if my father were driving it, it would have lasted another 1,000 to 5,000 miles perhaps.. Never the less, I changed the Head gaskets myself, and not I'm back again doing many WOT runs with the temps sitting at 196deg on the dash.. Now with my oil consumption back down to acceptable levels in my mind I'll be running 10w30 soon..

Also, I'm hearing a small knock from the motor when it's cold, when I 1st fire her up. I don't think it's piston slap, it's a rod bearing I'm sure, and of course with the different weights of oil I have used in the past month since the motor head gasket job was done, the sound is different with different oil weights. When I would fire up the car engine cold with 5w30 in the motor I would hear a kinda loud knock. With a weight mix "could not avoid it BBob" used a mixed of 5 qts 20w50 and 2 qts of 10w30, the knocking is much less obvious. Once the motor is up to operation temp the motor is very quiet.. I'll be changing the oil again soon to now straight 10w30 mobile 1 non syn, and let her run that for a while.. In my weird mind I was thinking the oil was too thin for the worn out rod bearings with 5w30 and too think for 20w50. So 10w30 would be best..

I do love the NStar motor.. Runs very strong and I get great gas mileage..

BBob I really like to read your posts. Be the way you are, "great"!! Your BLUNT nature is nice to read, not to mention your infinite knowledge!!!

Clint

BeelzeBob
05-03-05, 11:12 AM
Talking about Oil Consumption...

I bought my 97 Deville from my father. He told me often when he owned it that he needed to add about 1 qt of oil every 800 - 1000 miles or so.. He used the recommended 10w30 or 5w30. With 135,000 miles on the clock I took the car under my wing, and love it !!! I knew with the use of a little thicker oil, the oil consumption would decrease.. So I use 15w40, also my driving habits are completely different than my fathers. I go WOT often and drive aggressive, he's taps the gas here and there, just enough to get you to the speed limit. I noticed a big difference in oil consumption on my car now after driving it a while. After 10,000 miles from me, shes now down to about 1/2 a qt in 800 miles VS a full Qt. That's the positive, the negative is due to my aggressive nature on the throttle, that probably lead to a earlier HEADGASKET failure than if my father would have kept driving it around. Oh it still would have failed, that's for sure. But with my heavy foot often it lead to it earlier, perhaps if my father were driving it, it would have lasted another 1,000 to 5,000 miles perhaps.. Never the less, I changed the Head gaskets myself, and not I'm back again doing many WOT runs with the temps sitting at 196deg on the dash.. Now with my oil consumption back down to acceptable levels in my mind I'll be running 10w30 soon..

Also, I'm hearing a small knock from the motor when it's cold, when I 1st fire her up. I don't think it's piston slap, it's a rod bearing I'm sure, and of course with the different weights of oil I have used in the past month since the motor head gasket job was done, the sound is different with different oil weights. When I would fire up the car engine cold with 5w30 in the motor I would hear a kinda loud knock. With a weight mix "could not avoid it BBob" used a mixed of 5 qts 20w50 and 2 qts of 10w30, the knocking is much less obvious. Once the motor is up to operation temp the motor is very quiet.. I'll be changing the oil again soon to now straight 10w30 mobile 1 non syn, and let her run that for a while.. In my weird mind I was thinking the oil was too thin for the worn out rod bearings with 5w30 and too think for 20w50. So 10w30 would be best..

I do love the NStar motor.. Runs very strong and I get great gas mileage..

BBob I really like to read your posts. Be the way you are, "great"!! Your BLUNT nature is nice to read, not to mention your infinite knowledge!!!

Clint



What kind of knock do you hear at startup..??? I seriously doubt that it is a rod bearing. They just do not "wear" and make noise like that. The good news about rod bearings is that if they are quiet they are perfectly fine (and vice versa)...the bad news is that if you hear one knocking...it is too late...LOL

There can be some low level of piston slap in the Northstar on cold starts that is barely detectable but there on some engines. Everyone treads the fine line between piston slap cold and making the pistons light and low-friction. Unfortunately, most everything you do to a piston design to eliminate mass and friction tends to make it noisy. Doesn't hurt anything...just makes noise cold.

I would suggest the cold carbon rap as a possibility but it sounds like you air it out enough that that wouldn't be a concern.

Sometimes on a Northstar engine you can start it cold and let it sit and idle and it will be quiet for 15 to 30 seconds or so and then you will hear a ticking noise....sort of like a lifter ticking....that lasts for 30 seconds or so and then disappears. If THAT is the noise you are hearing then it is a wrist pin. The Northstar has full floating wrist pins and if they are clearanced like you would like for performance and low friction they will tick like that on startup. Same deal as the piston skirt design...performance oriented wrist pin clearances tick and "tight" wrist pins are quiet..but "tight" is not what is wanted for max performance. so...if you are hearing the tick like I described, don't worry. The wrist pins are on the high side of the tolerance for clearance and are excellent for performance.

BeelzeBob
05-03-05, 11:26 AM
I know this much - if the problem occurs because of tolerances upon assembly, were all in trouble. There shouldn't be that much difference between two N*'s, and all the oils have to meet the same standards, so that's not the problem either.:yawn:

In my case I don't have a problem with an engine using 1 qt. per 1000 miles. But I didn't expect it upon purchasing the car. All I ask is for the dearership to be honest enough to let the customer know so were not shocked when it takes place. :vomit:


The issue in the variability in oil consumption is not the "clearances" or "tolerances" at assembly.

The issue is some variability in the cylinder wall surface finish in the final honing of the block. There is a fairly tight range of surface finish requirements on the finish but within the narrow range of the surface finish on the cylinder walls there can be considerable variability in the oil consumption. Keep in mind that the more aggressive the hone pattern is the more oil is retained on the cylinder walls. This is good for lubrication and ring sealing but it does lead to some oil consumption. It is the nature of the beast when designing a high performance engine. It isn't a matter of poor quality control or loose tolerances or anything. The things like that...being piston fit, ring gap, cylinder diameter, etc.... are all controlled very tightly. The variability is strictly in the ring interaction with the cylinder walls and the surface finish of the cylinder walls.

The bright side of this is proven by the the repeated posts of folks taking the heads off at well over 100K and discovering that the cylinder walls look like new, that the rings/pistons virtually never wear out, the original hone pattern is still visible in the cylinder walls, there is absolutely NO wear ridge at the top of the cylinders, etc. The aggressive honing pattern is the way to go but it does lead to some oil consumption and some variability in oil consumption combined with the low friciton/low tension rings used for better performance and better fuel economy.

The furor over oil consumption is just completely overblown. Putting a fresh quart of oil in occasionally is good for the engine anyway as it adds a fresh spike of the antiwear additives in the fresh oil to the sump. I feel that the longevity offered by the design totally offsets the oil consumption seen. Oil is inexpensive and easy to add. Put it in and run the snot out of it and worry about something else. The thing that needs changing is the mindset that "oil consumption is bad" or that "oil consumption means that the engine is about to fail". It does not mean that. If an engine ran with absolutely no oil consumption and then suddenly started using a lot I would be concerned. Continuous oil consumption without tailpipe smoke that is regular and repeatable is nothing to be alarmed about. Honestly, I think a lot of engine engineers are surprised at the public outcry about oil consumption in some high performance engines like the Northstar. Every manufacturer has this variability in oil consumption to one degree or another. BMW specifically calls out to check the oil at every fuel stop in some of their M series engines as the oil consumption can be great enough between fuel stops to cause the sump to be low..!!! Not that every engine does that but some do with absolutely nothing wrong.


It is true that all the oils have to meet the same standard....but....there can be some difference in oil consumption between different types and different brands of oil. Seen it happen. Particularily synthetic oils seem to exacerbate the oil consumtion issue in the earlier model Northstar engines.

BeelzeBob
05-03-05, 11:27 AM
Hard to believe the half case is loosing a qt. per 300 miles. How about the oil lines at the filter adapter?


YEA....a 300 mile per quart LEAK would cause a giant puddle whereever you park.

BeelzeBob
05-03-05, 11:29 AM
bbobynski
I have tracked your advice on a number of cadillac issues and thank you greatly for your contributions, as a cadillac fan of 20 years and currently owning caddys from 50s to 90s i decided to put my money where my mouth was and was one of small number of people in UK who went and bought a new (RHD)99sts apart from being the best car i have ever driven one thing puzzle me.
The Caddy resellers in UK All put mobil 1 fully synthetic in all new STSs from day one, and subsequent lube changes, I have maintained this with all oil changes being fully synthetic, can you comment on the use of fully synth in the Northstar ?

PS did you work for Cadillac or on Northstar ? appreciate any comments

Cheers


Using the synthetic won't hurt anything at all. It is not really necessary but it won't hurt anything. Many people notice greater oil consumption with synthetic oil in the engine but that is not really a big deal to me.

Ranger
05-03-05, 06:48 PM
"I think a lot of engine engineers are surprised at the public outcry about oil consumption in some high performance engines like the Northstar."

In the past, using oil at the rate the Northstar does meant worn rings or bad valve seals. No one (except you) has bothered to educate the public. If GM put one of your explanaitions in the owners manual I am sure the perception would be much different.

Murphyg
05-03-05, 07:14 PM
"I think a lot of engine engineers are surprised at the public outcry about oil consumption in some high performance engines like the Northstar."

In the past, using oil at the rate the Northstar does meant worn rings or bad valve seals. No one (except you) has bothered to educate the public. If GM put one of your explanaitions in the owners manual I am sure the perception would be much different.

But wouldnt that create a lull in the amount of people that are worried about it, and so bring there vehicle in to be looked at ?
Dont alot of them charge bout $100 right of the top just to pull it into the bay ?
Has anyone ever called a dealer to ask about it ?
And if so what were they told ?
My guess would be: "Bring it in and we'll have a look at it". LOL

I know Id be concerned. Good thing there are places like this with individuals who are willing to help out.