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Discussion Starter #1 (Edited)
I ran across this web page of comments on the '97 Seville oil consumption problem,

http://www.carsurvey.org/viewcomments_review_17781.html

I recently purchased mine with 72,000 miles on it. I've put 4k more in the past month.

I just changed its oil 1k miles ago. After reading these comments yesterday I went out and checked my oil level. Damn! Wouldn't ya' know it, I was down a quart.

Guess this is common eh? (Read comment from a '99 Seville ownder and response from Cadillac below my signature.)

Anyone have their engines replaced because of this?

Anyone find another solution that helped?


..rickko..

'99 Seville:
Uses 1 qt. of oil every 1500 miles. Dealer says "they all do that". Hard to believe that this infamous Northstar jewel of an engine was designed to behave that way. It would be great if GM simply gave an honest answer - instead, you can read for yourself the canned "politically correct" response I received when I inquired. Read more at http://www.carsurvey.org/review_43806.html
 

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i HATE this problem.

My dad's 98' sts has the same problem :mad: The idiots at GM service keep sayin " we can't fix it " , and charge us extensional service fees, even though we have extended warranty.

It's a shame such a good engine has such a problem.

Caddy_enthusiast42
 

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1990 Acura Legend 174K+ miles Conventional oil maybe a cup in 3,500 miles.

Two 1995 Infiniti Q45 each less than 60K miles Mobil1 never any consumption in 3,500 miles.

How can GM compete? They cannot.

Brian
 

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maxnix said:
1990 Acura Legend 174K+ miles Conventional oil maybe a cup in 3,500 miles.

Two 1995 Infiniti Q45 each less than 60K miles Mobil1 never any consumption in 3,500 miles.

How can GM compete? They cannot.

Brian
you gotta understand the fact that northstar engine by design uses little bit of oil to lubricate itself for better protection. I don't mind burning a little oil knowing what it does. Just don't forget to check oil regularly

ps- engine was design in early 90s. tell me which engine competed with northstar back then. Now every manufacturer has similarly performing engine.
 

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You forgot to mention that the Northstar requires more oil just to compensate for this. It was all in the master plan. The engines run showroom-new long after 100,000 miles.
 

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I've heard this argument many times. I have but one thing to say about it.
If, as many people say, the Northstar engine intentionally uses oil to increase it's service life, then why don't ALL Northstar engines have high oil consumption?

Think about it.
 

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Katshot said:
I've heard this argument many times. I have but one thing to say about it.
If, as many people say, the Northstar engine intentionally uses oil to increase it's service life, then why don't ALL Northstar engines have high oil consumption?

Think about it.
what about driving habits? some ppl drive their car harder than others. Just like with same exact motor you don't get same amount of oil consumption
 

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Good old GM, of all the cars to superb oil life my POS 1995 taurus does not burn or even leak a single drop of oil. I spun a rod bearing at 78k and i just slapped a new bearing in it and it has clattered its way to 143k and doesn't use ANY oil. Thats crazy. My crx doesnt use a drop of oil either. Maybe that why i was so concerned about my caddy when i realized it uses a quart every 1200 miles. UHG!!!

Brett
 

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Oil Consumption

Oil consumption problem on by 97 Eldorado ETC. I discovered at 58K miles. Would not have known if I had not been on trip and decided to wait to change oil at 5K miles vs 3K miles. They change the oil twice, performed two of procedures to free up the rings and they just re-built the engine (rings, pistons, rods, chains,etc). The dealer had the car 79 days and picked up a rental. I got the car back and 2 days later the car is dead. They paid for towing and replace battery. I have the car back for two months ( 2000 miles) and the oil light is on agarin.

I got it back yesterday and now we are starting all over again. They change the oil and told me to bring back in 1000 miles. I fiqure they have spent about $8000 dollars to date on this problem. The car rental bill was $2900 alone.

The original sales manager at the dealer warned me that this will be a long journey. He inidcated that 90% of the time all this work will be a waste of time and they will need to replace the engine. It appears he was not BSing me.

Thank God for the extended warranty on the car. I bought a Ford Excursion last year and place the warranty on this vehicle. If you are spending $35K or more for a car than your are foolish not spend the extra $1200 for warranty. I kept viewing posts about the car(s). Anytime I see a problem, a similar complaint goes in on mine. Usually it take two complaints and they replace the part. I use the insurance to my advantage.
 

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Re: Oil Consumption

I had the same problem in my '95 STS, every Cadillac dealer and good mechanic I speak to say ONLY run synthetic oil in Northstars. After I switched to Synthetic, oil consumption is not an issue any longer. I thought most other Northstar owners did the same, am I not correct?

What oil and weight are you using?
 

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plz bear with me...first time interacitng...about a car...just purchased my first Cadillac, like there might be more???...a '97 Seville SLS. I love it, REALLY love her....a bit intimidated with all the info out there, but feel fortunate I read about this oil thing. I'll definatley watch my oil now. I know I can proably find this info in the manual the caring previous owner left in the car, but you all seem so well versed in this area I thought I'd run it by you...what type of oil should I use....and shouldn't I know what 'has' been used...I've heard you shouldn't change the type in the middle of the stream. Like I said I just got her, 5/31/04 in fact, she has 43,000 mi and everything seems to be in EXCELLENT working condition...hope it stays that way, what with reading some of the complaints on line....thx
 

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Susan.

There were several long threads about which brand or type of oil to use. The short answer is any quality oil in the right weight(like 5W20 etc). It doesn't matter what was used before. Just change the oil and filter.
 

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Susan Stohr said:
plz bear with me...first time interacitng...about a car...just purchased my first Cadillac, like there might be more???...a '97 Seville SLS. I love it, REALLY love her....a bit intimidated with all the info out there, but feel fortunate I read about this oil thing. I'll definatley watch my oil now. I know I can proably find this info in the manual the caring previous owner left in the car, but you all seem so well versed in this area I thought I'd run it by you...what type of oil should I use....and shouldn't I know what 'has' been used...I've heard you shouldn't change the type in the middle of the stream. Like I said I just got her, 5/31/04 in fact, she has 43,000 mi and everything seems to be in EXCELLENT working condition...hope it stays that way, what with reading some of the complaints on line....thx

Just to eliminate any confusion you should be using 10W30 oil in your engine. Synthetic is not required nor recommended. Any good quality conventional motor oil is fine. Look at the can or bottle for markings that signify that it is rated SL for service and also look for the GF3 "star burst" rating that says for "gasoline engines". That's really all that's required. All the rest is marketing and hype. A good conventional oil like Mobil "drive clean" or Texaco "Havoline" oil is great.
 

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Here's a repeat of about the most concise version of the great "oil consumption debate" that I have. There's lots more info and discussion in the archvies if you search using "oil consumption".

The the way, it's interesting to note that most every manufacturer has some verbage in their literature explaining that oil consumption of 1 quart in 1000 or 1500 miles is considered "normal" as most every manufacturer has similar inconsistencies with oil consumption due to production variation. BMW has such high consumption on some of their "M" high performance engines that they specifically call out in the owners manual to check the oil at every gas stop as the consumption rate in high speed driving may be great enough to lower the sump sufficiently in one tank of gas to require oil addition. Read the BMW forums if you think Northstars are the only engines that use a little oil. :p

Here it goes. And please excuse the redundancy in the opening lines as this has been cut and pasted several times in similar posts.

The Northstar engine will characteristically use a little more oil than some other engines but that's not a sign of the engine failing or of anything wrong. There's no final answer on the oil consumption issue. I put the following thoughts together some time ago in response to this type of question so hopefully it'll still apply here:

The following wandering thoughs were put down in answer to the ongoing oil consumption discussion and I thought that it might be good to get additional mileage out of it here to. If interested, read on...

The comment was made about the variance in oil consumption on Northstar engines being more of a concern than the actual consumption of any given engine - thus the following comments.

Good point about the difference in consumption...

The real issue is the limitations of the production tolerances on the honing process for the cylinder bores. Size is no problem. They're all dead nuts. Surface finish is the issue. It's imperative that the "smoothest" possible surface finish from the process retain enough oil to not starve the top rings under continuous heavy load and high RPM. Unfortunately, to make the smoothest possible surface finish "rough" enough to retain oil, the resulting "roughest" or most aggressive surface finish the process is then capable of will contribute to a 1000 miles per quart or worse.

There's really no magic here. All the automakers have access to the same honing process and honing equipment manufacturers. Thus, they are all "stuck" with the same variation in production. As engine specific outputs have risen and the operating RPM of the engines have risen over the years all the engine makers have gone to a more agressive surface finish for proper oil retention. And all run into the same situation with variation in oil economy. If you do some reading and research you'll find that all engine makers will state that roughly 1000 miles per quart is "acceptable" or "normal" in some fashion.

Not to say that the 'average" engine gets that oil economy - but - an engine that gets 1000 miles per quart will have absolutely nothing wrong with it at disassembly and inspection.

The fact is that the engines that tend toward the high end for oil consumption seem to look the best at high mileage. Whether it's the higher oil supply to the top of the piston or the frequent spiking of the oil in the sump with fresh additives due to more frequent adds (or both) is up for debate.

Back in the "old days" of 350 cubic inch engines that made 180 horsepower it was entirely possible to make the cylinder walls mirror smooth and the engine would live and use virtually no oil. Won't work today with the HP over 1 horsepower per cubic inch and RPM up to 6000 continuos and 6500rpm shift points. The top rings wont take it without microwelding to the ring lands of the pistons.

The honing operations have received many improvements over the years as technology in the honing arena improved. Today, diamond stones with a water based honing coolant is the norm for long life stones that don't change over time. The older processes with vitrous stones and honing oil change significantly as the stones break in and wear and the stones had to be changed frequently as they wore out. So each hone was going through a continual cycle of break-in and wear out of the stones. Generally on a V8 two cylinders on each bank are honed at a time and then the other two are done in the next station by two other stones. So any given engine has 4 different honing stone sets in the differenct bores. Depending on what the life of the stones is and when they were being replaced there can be some variation in the surface finish (in regards to oil consumption) from cylinder to cylinder and bank to bank. Usually when the stones are new they make the most aggressive cut and leave the most aggressive pattern. The stones get smoother as they wear and the pattern gets less agressive. All the stones are "broken in" in initially on scrap blocks but there's obviously some change in the next several hundred blocks.

To put things in perspective, an average engine builder might hone one or two engines a week. A major NASCAR engine builder might do 400 or 500 engines a year. Every day the engine plant that makes Northstar engines hones 1000 blocks. That's 8000 bores. And even more are done on a lot of days. The 1000 number is very loose. There's a great deal of process control placed on the cylinder wall surface finish but the inherent variences in the process will certainly lead to a considerable difference in oil economy in some engines - and absolutely nothing will be wrong with them.

Personally, if I could pick my engine from the line, I would go for one that uses about 1500 per quart. Seriously.

One thing that was done on the original Northstar engines was a process called plateau honing. In this process the cylinder walls are "marked" with a very agressive hone that leaves fairly deep scratches. The high points of the hone pattern are then smoothed with a second hone plateauing off the tops or tips of the "peaks". Under a micorscope this looks like a flat platueau with relatively deep, narrow crevices for oil retention. This process worked very well for oil retention and durability but was inconsistent for oil consumption to some extent. The current process has been improved with a more conventional hone that's not deliberately plateaued and is more consistent. Plus it uses the diamond stones that last far longer and are much more consistent over time.

The other thing that the modern engines sacrifice oil consumption for is friction. The thinner rings and lighter spring load rings are desireable for power, sealing of compression, less friction and lighter mass for less ring flutter at high speeds. Unfortunately, there's no free lunch here, and the lighter rings let a little more oil by.

The 2000 and later Northstar engines get hard anodized top ring lands to resist pound out and wear since the ring lands were moved closer to the top of the piston. One unfortunate side effect of the hard anodizing is the microscopic "pebbly" finish of the anodizing that tends to cause lack of seating of the SIDE of the ring to the SIDE of the ring land. This pebbly area will retain oil and cause oil consumption until the anodizing is polished smooth as the rings "break in" to the ring lands. The anodizing is hard, however, so that's why the "drive it like you stole it" advice works, particularily on later Northstars, to ensure good break in and sealing for less oil consumption. Many of the oil consumption complaint engines that have been analyzed at the factory had the anodizing on the piston ring lands virtually unscathed - as in never broken in due to gently driving and babying. The engine likes heavy loads, high RPM to break in completely.

The heavy load/high RPM also promotes ring rotation on the piston to keep the rings freed up and mobile. The oil comsumption complaints from the older Northstars typically come about due to ring sticking in the ring lands due to carbon buildup and the rings gradually getting stuck in place. They have to move to work. Keep them exercised.
 

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I am bewildered and still unsure what to think of the oil consumption problem. My 1994 Eldarado has 135,000 on it now , it too has an oil consumption problem though mine is not as severe as some of what i have read here. The day i purchased my car (as i always do) i changed the oil in the car after first flushing the system. I use ONLY Mobil 1 motor oil in every vehicle i have ever owned that has more than 100,000 miles on it. Also there is a wonderful product that i have only found at Napa auto parts called Seafoam used to clean the fuel injection system. My oil is being consumed more than what is usual in any other auto i have ever owned. i have had my car now since the first week of April and have used the oil down to the point it needs more added. When i stop my car after a long trip (45 +miles) burning oil (small occasional clouds of smoke) rise slowly from under the passenger side of the hood i have yet had the opporitunity to put the car on a lift to try and track down where the leak orriginates. I was until reading these posts under the impression that the leak my eldorado has was caused by worn or damaged parts. I am now thinking a lot differently about that. I will not sell ro get rid of the car. I have never owned a faster, more comfrotable or more sporty feeling full sized luxury car. I am still much impressed with the speed and pickup of the 32 valve Northstar motor. I was initially convinced that was just a marketing ploy like adding a bunch of fancy high temp plastics to the motor to make it more appealing to the eye. now owning one i see that is not the case. i am further impressed with the fact that i can get up to 50 miles an hour and stomp the gas and make the tires turn over. That's power. I don't do that regularly but i did put the car through the paces while on the test drive. i also saw an article about these cars over heating easily and causing the motors to have to be rebuilt. Are there any more inclusive forums or article sites that post a more model specific listing of comon problems?
I just like to know what I am in for and i love to be completely informed. as impressed as i am with this car we may just become a cadillac family soon. look forward to adding an escalade and an Alante to the garage and selling off the other 3 vehicles we now have. i am a GM guy from way back , no contests between Ford and Chevy in this house. any hints and helps or other links would be greatly appreciated. also looking for a new arm rest with the cupholders not broken off that is cosmeticly the only imperfection on my Eldorado.
 

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The ironic part is that many of these posts prove what I say all along. That the Northstar is being it's own worst enemy. People are buying these cars used with near 100,000 miles on them and they run so good that all they complain about is them using a little oil. What's not to like. 100,000 is a lot of miles, people. That used to be the end of a car's life not too long ago. Now you have 135,000 on it, it runs like brand new and you don't know what to think about a little oil consumption. I'll tell you what to think. Pour oil in it and forget about it. Worry and fret about what's on TV tonight and forget about impending doom due to 1000 miles per quart. Drive it hard and fast and it will like it and run that way for a long time. Doesn't it sink in that the engines are capable of running for hundreds of thousands of miles with little or no wear? If they were wearing out the oil consumption would get a LOT worse, they would smoke while driving, you would have no power and they would be noisy and break down all the time. They're not wearing out. Get used to a little oil consumption. Take advantage of all the good things about the engine and accept the fact that it needs a little oil occasionally.
 

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Katshot said:
I've heard this argument many times. I have but one thing to say about it.
If, as many people say, the Northstar engine intentionally uses oil to increase it's service life, then why don't ALL Northstar engines have high oil consumption?

Think about it.
The fact is that they all DO use a little more oil than comparible engines of the past. They're not completely "dry" as has been stated many times before.

The variability in the oil consumption has also been touched on many times in other posts. The variability comes from the cylinder honing pattern. The plateau type honing process isn't as consistent in production as is most desireable. It's a good way to get oil to the upper rings and keep the cylinders and pistons happy. But it can lead to higher than designed consumption in cases where the honing process is at the far end of the process control. THAT is why they're inconsistent. The inconsistency of the oil consumption does NOT disprove the fact that the engines are set up to use some oil.

The evidence is clearly there that the oil consumption and the cylinder surface finish and ring pack promotes long engine life. Just read the posts by owners that have done head gaskets and that comment on the fact that the engine cylinder walls look brand new with over 100,000 miles on them. You used to have to use a ridge reamer to cut the ridge down that was worn in the top of the cylinder to even get the pistons out of engines years ago. Now this one can go 100,000 miles and the factory surface finish is still visible in the cylinder walls. Isn't that worth a little oil consumption?

The mindset that oil consumption equals poor quality or poor design is just plain wrong.
 

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Re: Oil Consumption

Think how much you could have saved in time and trouble by just putting oil in the engine and driving the heck out of it. It was fine all along and the service manager was right. A little oil consumption never hurt anything.



naughtyknuty said:
Oil consumption problem on by 97 Eldorado ETC. I discovered at 58K miles. Would not have known if I had not been on trip and decided to wait to change oil at 5K miles vs 3K miles. They change the oil twice, performed two of procedures to free up the rings and they just re-built the engine (rings, pistons, rods, chains,etc). The dealer had the car 79 days and picked up a rental. I got the car back and 2 days later the car is dead. They paid for towing and replace battery. I have the car back for two months ( 2000 miles) and the oil light is on agarin.

I got it back yesterday and now we are starting all over again. They change the oil and told me to bring back in 1000 miles. I fiqure they have spent about $8000 dollars to date on this problem. The car rental bill was $2900 alone.

The original sales manager at the dealer warned me that this will be a long journey. He inidcated that 90% of the time all this work will be a waste of time and they will need to replace the engine. It appears he was not BSing me.

Thank God for the extended warranty on the car. I bought a Ford Excursion last year and place the warranty on this vehicle. If you are spending $35K or more for a car than your are foolish not spend the extra $1200 for warranty. I kept viewing posts about the car(s). Anytime I see a problem, a similar complaint goes in on mine. Usually it take two complaints and they replace the part. I use the insurance to my advantage.
 
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