: This whole WOT thing....



VinnyT
10-27-05, 03:38 PM
Just my .02: I can't see how doing repeated WOT will benefit the Northstar. If the only thing it helps is reduce oil consumption, then I'll add the oil when it needs it. I just can see any benefit with incurring damage elsewhere. WOT causes tremendous strain on the bearings, connecting rods, valves not to mention the tranny and CV joints. Anyone else feel this way? Can anyone give me proven reasons for doing this?:ill: V.

mcowden
10-27-05, 03:57 PM
Just my .02: I can't see how doing repeated WOT will benefit the Northstar. If the only thing it helps is reduce oil consumption, then I'll add the oil when it needs it. I just can see any benefit with incurring damage elsewhere. WOT causes tremendous strain on the bearings, connecting rods, valves not to mention the tranny and CV joints. Anyone else feel this way? Can anyone give me proven reasons for doing this?:ill: V.

The primary rationale is that it helps clear out carbon from the piston ring lands, and thereby helps reduce oil consumption. It's also supposed to help blow out and/or burn off carbon from the piston crowns. Here's a better question: Has anyone damaged their engine by doing WOT, or been told that their engine , transmission, or CV joints failed because of previous liberal application of WOT? My guess is the answer will be no. I beat the crap out of mine as often as I can, it has almost 97k miles on it, my oil consumption is negligible, I have no "cold carbon rap" problems, and I have experienced no problems that I would consider out of the ordinary and certainly none that I can directly attribute to WOT. I think you'll have more complaints by letting the carbon build up, and I think you're worrying about it too much.

eldorado1
10-27-05, 05:04 PM
My advice:

Sell your car and buy a Honduh. Someone else could probably use the torque better. :lildevil:


Seriously, if you worry about component failure all the time, maybe you should stay inside? The sun's rays can give you cancer. Don't eat barbeque'd food either, the charred food gives you cancer too. And don't open the windows, you could catch a chill and get pneumonia.

...or not. :bonkers:

VinnyT
10-27-05, 05:04 PM
I'm not worried about it, I just think it is hell on the car and unnecessary. :cool:

caddydaddy
10-27-05, 05:09 PM
It's a tough engine, built for running at 6,000 RPM's plus. And the transmission is one of the heaviest and strongest FWD trannys that's out there!

eldorado1
10-27-05, 05:12 PM
Well the more revolutions an engine makes in it's life, the shorter it's life will be, everything else being the same... But bearing and valvetrain failures just don't happen. (at least in our engines)
If you want a reason to do your WOT's, how's this... By exercising the rings, they seal against the cylinder liner better. Even a marginal 5psi improvement (VERY easy if they were stuck due to carbon buildup) would mean an extra 10hp.

eldorado1
10-27-05, 05:17 PM
WOT causes tremendous strain on the bearings, connecting rods, valves not to mention the tranny and CV joints.

PS - have you ever seen any of those failures here? Can you name anybody who's had a bearing failure? CV joint failure?

I know of a few connecting rods that let go and grenaded the engine, but that seems to be isolated compared to head gaskets. ;)

Ranger
10-27-05, 06:05 PM
Go to the top left of this page, click on Technical Archives and read up on Occassional Full Throttle Acceleration. It was written by our old friend.

VinnyT
10-28-05, 08:26 AM
I did go to the Tech archives earlier. I just never heard of doing WOT shots for routine maintenance. I'll try it this weekend.:lildevil: I had a 1998 Z28 with the LS1(aluminum block) and it also has cold piston slap, Sounded terrible. I got rid of it 2 months later; what a POS! Wasn't trying to argue with anyone on this subject, just wanted to get other opinions. Thanks all! V.

elwesso
10-28-05, 12:38 PM
Generally speaking, the redline is a VERY safe "RPM limit".. I think that the northstart could probably rev to 7000 RPM without any problems.....

Basically assuming the oil is fully warmed up, they design things to be redlined every shift...

Now if the head gasket can take it is antoher story... :)

tripowerbird
10-28-05, 07:42 PM
Just my .02: I can't see how doing repeated WOT will benefit the Northstar. If the only thing it helps is reduce oil consumption, then I'll add the oil when it needs it. I just can see any benefit with incurring damage elsewhere. WOT causes tremendous strain on the bearings, connecting rods, valves not to mention the tranny and CV joints. Anyone else feel this way? Can anyone give me proven reasons for doing this?:ill: V.

Because it puts a big ass smile on your face to watch those hugging your bumper on an on-ramp fade into the distance as the ramp straightens and your right foot plants it to WOT.

danbuc
10-28-05, 08:28 PM
If you don't ever give the engine WOT, it never has a chance to make it's maximum power. That's one thing I never understood about peopel who say WOT is bad for these engines. They have obviously never felt the N* perform how it was designed to. Any engine that produces 300hp at 6000rpm is made to rev high and hard.

MWA
10-29-05, 07:14 AM
Vinny,
Purchased a used 98 Eldo from a dealer and the service dept had maintained it for the gentleman like a watch. After coolant, tran fluid, and other service checks, I still worried about oil consumption. Checked behind the scenes with the old line tech at the dealer and he related that the original owner only drove it about 55 and to decrease the oil consumption "run it like I stole it." Did just that and the tech was exactly right. Only experience that I have ever had like it is riding coach in a commercial 737. Try it, you'll like it....just make certain that fluids are current and correct and read up on the tech archive above, like the Ranger advises. Just like Coca Cola Classic, its the real thing, baby!

Painless
10-31-05, 05:34 PM
Well then... I didn't buy my STS to go fast or even try to brag about it..(My Elcamino has 430 rwhp) cuz it's just not fast.. It's fun to drive and it's quick, gets good mileage by comparison to some other cars I've had over the years...

My N* uses about a quart every 3000 miles... Which to me, is pretty normal and acceptable for 111k miles! Granted I don't drive it like a grandma, but I don't drive it like I stole it either.. Don't plan to, that defeats the purpose of the MPG I try to maintain! If all I'm gonna do is beat it to the redline every time I get in it I may as well drive the muscle car.. It gets 21mpg highway...

I've heard of MANY N* probelms with transmissions/ head gasket problems etc... Be nice to your car, keep the fluids current and run premium fuel = Better running / Longer lasting car then one that's stomped on every day!

malcolm
10-31-05, 05:56 PM
I am not against WOT and put my foot in it every chance I get but outside of this forum I never heard of it.

auroradude
10-31-05, 09:37 PM
I used to do that every day with my Rora. Only problem is it was getting to be too much and I realized that is why my engine accessories keep going out all the time (all the original components like water pump, EGR etc). I let it shift at 3000rpm all the time now and only floor it when passing a whole assload of cars. I did 110 this morning just passing people the whole time. Now that is fun, but i only do it when i have to.

mcowden
10-31-05, 10:18 PM
I used to do that every day with my Rora. Only problem is it was getting to be too much and I realized that is why my engine accessories keep going out all the time (all the original components like water pump, EGR etc). I let it shift at 3000rpm all the time now and only floor it when passing a whole assload of cars. I did 110 this morning just passing people the whole time. Now that is fun, but i only do it when i have to.

You know, things like EGR valves and water pumps are normal maintenance items. How many miles were on your Aurora when you had those problems? I believe you'd have the same problem with WOT or without. Aside from that argument, going 110 in traffic is a good way to get yourself and somebody else killed, not to mention jail time and insurance premiums. How is that easier to justify than WOT??? You're not making any sense, man. :helpless:

Ranger
10-31-05, 10:36 PM
110 passing a line of traffic. Obviously you didn't think of it at the time but now imagine some old bluehair or some inexpirienced kid deciding to pass in that line and he/she doesn't bother to check the rear view mirror before pulling out. Life as a paraplegic or quadraplegic can't be fun.

Painless
10-31-05, 10:53 PM
Wow, after reading all this you'd think one would believe that driving at redline is gonna make thier car last longer!! Driving a car hard might keep the combustion chamber cleaner but it's not gonna magically make the car last forever! All parts wear out and routine WOT driving WILL wear parts out FASTER.... These cars might be tough enough to endure this kind of driving for quite some time but quality and timely preventive maintenance is the key here...

Everyday start and stop - short trips, around town kinda driving will build up some carbon etc.. and would benefit from an occasional blast down the road. But, highway miles are what puts record miles on cars! NOT WOT driving!! "Racing" your car to make it last longer?? That's just rediculous! Ever watch drag racers?? Things break from WOT.. Things break from use of HP! IT IS FUN.. I'll be the first to admit it, but dont' think you have to do this to keep your caddy in good shape!! LOL

Like to race and go fast allot?? Buy/Build a car meant for it and save your caddy for the Luxury driving it was intented for!!

I like to race.. I'll drive 150mph on the street.. I've even make videos of my car! I'll never abuse my Caddy like that, But I'll pass Grandma....:halo:

www.josephgoss.com/ElkyVids/elkyvid1.wmv (http://www.josephgoss.com/ElkyVids/elkyvid1.wmv)

danbuc
10-31-05, 11:15 PM
When most of us reffer to WOT, we don't mean we're going flat otu down a highway as fast as we can with our foot to the floor( although many of us have done that on occasion). I do WOT maneuvers with my car every day. Th edifference is, my car is only at WOT for brief moments, maybe 10-15 seconds at most. Usually, I'm trying to get ahead of someone in traffic, or just messing around.

Also, I don't think you fully understand the WOT procedure that most of us are describing for blowing out carbon. Drving flat out as fast as you can couldn't be further from what most of us do when we want to blow out alot of carbon. You put the shift in second and run the car up to about 75-80mph from 25 or so, and then let the engine brake the car back down to 25 or so mph. Doing this 3 or 4 times (or until the cloud is gone) every once in a while (provided you reare;y give it WOT) is what we suggest to others who are wondering how they can descrease oil consumption. This procedure does work, and has for many people.

Most of us never drive at WOT down the highway for extended periods of time, because that's a sure way to where stuff out quickly. The occasional rev to 6000rpm does help keep the rings seated, and isn't necessarily bad for these engine. As I mentioned before, what's the point of having an engine that was designed to produce it's maximum output at 6000rpm, if you never let it rev to that point. That's liek driving an S2000, but never shifting past 5500rpm. You might as well be driving a Taurus or something.

Ranger
10-31-05, 11:31 PM
The key word here is ocassional. To me that means once or twice a month. Keep in mind that cruising along at 70 MPH my SLS is loping along at 1950 RPM. Highway mile don't keep these thoroughbreds cleaned out like the 350's, 383's, 427's etc of old days.

auroradude
11-01-05, 12:34 AM
I take painless's standpoint here and disagree with most of the others that I can see above. While i agree with the ring seating and piston slap stuff, a good WOT run or 2 every week is healthy. I went WOT for the first time in a week this morning with that little escapade.

My aurora had between 77k - 88k that it has now when this stuff happens. It all happened at different intervals. I just did the short blasts too (like maybe 5 seconds of WOT, or 0-110 sometimes then back off for the rest of the week).

If you kick it's ass every day, every shift that can't be good for it. Doesnt matter what oil you use, racing coolant racing this blah blah. It cant possibly be good for the headgaskets either, which is why i baby the car pretty much. Not like Grandma does with her Buick, but overall 3k shifts.

danbuc
11-01-05, 01:16 AM
First of all, there isn't enough cylinder pressure to blow a head gasket in these engine, even at WOT. It's corrosion from poorly maintained coolant, or overhjeating that makes the headgaskets fail. Second, excessive carbon buildup is probably what aided in the failure of your EGR. They get gummer up with crap, and then the pintle stops moving and it no longer flows exhaust gases anymore. The waterpumps on these cars are known for being replaced once around 60-70k miles. I had to have mine replaced at 60k because the housing was leaking badly. If your EGR and Waterpump were constantly failing, it was not do to WOT, but rather something wrong with the car.

Also, the harder you drive these cars, the harder they shift. Hard, firm shifts are great for auto transmissions. Unlike the regular, "smooth as butter" shifts which are designed to slip the clutches and steel plates, harder firmer shifts result in less slippage, and thus longer tranny life. Most people think that a firmer shift is a bad thing when it really is much better. Poeple will argue that the additional shock to the drivetrain is causing damage, but unless your raising the line pressure purposefully every time you shift, the difference in pressure is negligible.

As far as kicking it's ass every day, that would entail WOT at every single stop light, and going WOT down every stretch of highway you could find. Even then, you probably wouldn't be doing much damage at all. It may have been mentioned before, but many of these engines have been torn down, only to find that the cross hatching on the cylinder walls, is stil clearly visible even after 150k miles. Try finding the crosshatching on a 350 after that many miles. Second, being a DOHC engine, it is more than capable of revving to high rpms safely. It's what's so great about the DOHC design.

Finally, never shifting your car over 3000rpm is probably doing more harm than good. These engine were not designed to sit around waiting for someone to hit the gas. They were designed to rev hard and fast. I still think it's a tad bit unfortunate that the vast majority of N*'s out their don't ever get to excersise their full capability, but that's what happens when you stick a high perfornace DOCH all aluminum V8 in a large luxury sports sedan marketed to the eldery, and those having a mid life crisis.

I~LUV~Caddys8792
11-01-05, 01:20 AM
danbuc, does all this apply to just the N*, or all motors?

auroradude
11-01-05, 01:40 AM
Does this apply to my 4.0 "Baby Northstar" Aurora motor is what Im curious about.

I just dont relate to his posts man. I dont understand how an engine that lives at 6k rpm 80% of its life is going to last longer than an engine that is shifted at 3500-4k most of the time, with a couple hard, long blasts every week. I just don't.

There are several members on our board who are approaching 300k miles (all highway) owned the car since new and everything runs great. You think they FLOORED it all out all the time like that? No. Infact they cant even wind it up all the way anymore as most of the power that was once there, has infact gotten up and gone away.

The transmission thing is another story. I can understand about that, as my tech also rebuilt transmissions, including the tough GM FWD ones in the late 80s and early 90's. If you change your tranny fluid once a year like I do you shouldnt have any problems either. I just have the pan dropped and filter changed. Tranny shifts flawlessly.

Painless
11-01-05, 01:41 AM
As far as kicking it's ass every day, that would entail WOT at every single stop light, and going WOT down every stretch of highway you could find. Even then, you probably wouldn't be doing much damage at all.

Cool, you do it every time and see how long lasts!


It may have been mentioned before, but many of these engines have been torn down, only to find that the cross hatching on the cylinder walls, is stil clearly visible even after 150k miles. Try finding the crosshatching on a 350 after that many miles.

Uh.. Lets see.. the last chevy 350 I went into had over 300k miles and still had some cross hatch marks... Was in a silverado and used Amsoil it's whole life.. 1 for Amsoil!

Finally, never shifting your car over 3000rpm is probably doing more harm than good. These engine were not designed to sit around waiting for someone to hit the gas. They were designed to rev hard and fast. I still think it's a tad bit unfortunate that the vast majority of N*'s out their don't ever get to excersise their full capability,

NEVER being the key word here.. I agree with you on that.. Occasionally will do it some good.. I just don't agree on how often some people consider occasionally and to what degree would be considered "good" To each their own...


but that's what happens when you stick a high perfornace DOCH all aluminum V8 in a large luxury sports sedan marketed to the eldery, and those having a mid life crisis.

Oh, only two groups of people drive these?? So what group do you fall in? The elderly.. or in the mid life crisis?:alchi: LOL had to ask!

auroradude
11-01-05, 01:47 AM
Yeah man just drive your cars the way you want, and we will all sit back and watch how long they last. I put 5k miles a year on my car (although about 7k now with school + lotsa work) while you drive prolly like 20k right? Ok we will see...LOL.

davesdeville
11-01-05, 06:59 AM
Uh.. Lets see.. the last chevy 350 I went into had over 300k miles and still had some cross hatch marks... Was in a silverado and used Amsoil it's whole life.. 1 for Amsoil!

Oh, only two groups of people drive these?? So what group do you fall in? The elderly.. or in the mid life crisis?:alchi: LOL had to ask!

Consider yourself lucky with that 350. They're not known for their superior iron quality...

"Marketed to" :rolleyes:

Painless
11-01-05, 09:41 AM
Consider yourself lucky with that 350. They're not known for their superior iron quality...

"Marketed to" :rolleyes:

I guess I'm just always a lucky guy.. That isn't the only 350 I've seen like that... just the only one with that many miles! Seen many with at least 150k miles that still showed cross hatch marks.... In fact, I've seen many other brand motors with that many miles and more in the same condition! IT's all in the maintenance.... The cross hatching provides a means to lubricate the cylinder.. it's not suppose to go away. Rings aren't going to cut the marks out unless there was another reason that led to a failure..

VinnyT
11-01-05, 10:22 AM
I guess what I don't understand is that the Northstars are more or less performance engines. Many Caddys are NOT performance cars. On top of that, the main class of people buying these, especially the Devilles, are older retired people. They will not run these engines hard. If that is the case, why do they have the Northstar in these "conservative" cars? Now, don't get me wrong, other Caddy models are made for sport than cruise which would give reason for the N* engines. I bought mine with 64k on the clock, and I have no idea what driver was before me. I just don't want to start WOT and have things fail. It runs great now after some tune-up parts replaced(plugs, wires, coolant, etc). I can't believe there are no over-the-counter cleaners or additives to help reduce the carbon build-up. I throw in a bottle of injector cleaner every second fill-up. As for the Chevy 350's, we are talking apples and oranges. I had several cars with them, and were pretty reliable. Most didn't last because they were treated like hi-po motors, even the smogged out ones. I still debate the WOT thing for reasons stated above. I guess 'to each his own'. V.

mcowden
11-01-05, 01:00 PM
I guess what I don't understand is that the Northstars are more or less performance engines. Many Caddys are NOT performance cars. On top of that, the main class of people buying these, especially the Devilles, are older retired people. They will not run these engines hard. If that is the case, why do they have the Northstar in these "conservative" cars? Now, don't get me wrong, other Caddy models are made for sport than cruise which would give reason for the N* engines. I bought mine with 64k on the clock, and I have no idea what driver was before me. I just don't want to start WOT and have things fail. It runs great now after some tune-up parts replaced(plugs, wires, coolant, etc). I can't believe there are no over-the-counter cleaners or additives to help reduce the carbon build-up. I throw in a bottle of injector cleaner every second fill-up. As for the Chevy 350's, we are talking apples and oranges. I had several cars with them, and were pretty reliable. Most didn't last because they were treated like hi-po motors, even the smogged out ones. I still debate the WOT thing for reasons stated above. I guess 'to each his own'. V.


If WOT was such a problem, why didn't they put a rev limiter on it so you couldn't exceed 4000 RPMs? You guys worry too much. Just drive it however you want and stop obsessing over this kind of stuff. If you want to WOT it, do it and don't look back. I seriously doubt you're going to break or wear anything out as long as you're not drag racing it every day. If you don't want to do it, don't do it. Just realize that the occasional WOT was recommended by an engineer who was intimately familiar with the engine and its design, testing, and manufacturing. I think he wanted to see these cars last a long, long time, and I don't believe he would have told us to do something that was going to be harmful. There has been zero evidence that it causes any problems so far.

VinnyT
11-01-05, 01:17 PM
I must say my interest in this WOT has waivered. Silly, argumentitve posts are unnecessary. I was just curious about the technique, that's all. Just because one GM technician said "Yeah, do it", doesn't mean I will. Thanks for the interesting responses, but this is another thread that has gotten stupid. Please close it. V.

mcowden
11-01-05, 01:18 PM
I must say my interest in this WOT has waivered. Silly, argumentitve posts are unnecessary. I was just curious about the technique, that's all. Just because one GM technician said "Yeah, do it", doesn't mean I will. Thanks for the interesting responses, but this is another thread that has gotten stupid. Please close it. V.

Done. You take this stuff too seriously, man.

Ranger
11-01-05, 09:56 PM
Vinney,
Not to belabor this topic but you asked "why do they have the Northstar in these "conservative" cars?". I think the answer is that Cadillac has always been known for luxury and power. Along comes the 80's and the Diesel and the HT4100, neither of which could get out of their own way. Cadillac had to do something to regain their status. The Northstar did that.

BTW, it wasn't a GM tech that advised WOT it was an engineer who was involved in designing, and testing it. He was quite knowledgable and gave us much good advice. As you probably have noticed, those of us who knew him, trust his advice.