I have an STS with 58,000 miles and the North Star engine has been nothing but a nightmare. Luckily I have an extended warranty. The engine uses oil, had to have the oil pan resealed, and now the head bolts pulled from the block and had to have inserts installed. My son, who has the same engine with 80,000 miles on his car and he had the identical problems. After talking with several mechanics from different dealerships and mechanics from privately owned repair shops, they all say the North Star engine is notorius for these problems. Why doesn't GM correct the problem? Aside from the instrument cluster going out, all problems have been with the engine. If the problems were something other than the engine, the car would be a winner but when you pay $55,000 plus for a car, you would expect something better. In my opinion, GM should correct this problem or quit selling any vehicle with a North Star. The engines are worthless when it comes to reliability and ongoing expenses. The cost of the inconveniences and repairs is not worth the performance. It's a repair money maker for the dealerships since the vehicle stays in the shop. I have owned a Porsche, Corvette, and now a Viper and the performance exceeds the North Star with virtually reliabilty problems - no oils leaks, high oil consumption, or fear of what's going to go next? I'll never own another North Star unless these problems are corrected. There are no excuses for these continued problems and this engine gives Cadillac a bad reputation!!!!

Ron could you tell us abit more about your STS? Used or New? what year? etc.

Also, incase you haven't already read this, here is the answer to the oil consumption issues on the N*; its quite common, and maybe if you read this you can understand it better. Remember, these are "touring" engines and everyonce in a while they need a good WOT.:sneaky:

Here's the answer to your problem (hopefully):

http://www.cadillacforums.com/cadillac-tech.html#noil

I have an STS with 58,000 miles and the North Star



the northstar engine is a high performance engine that NEEDS to be broken in CORRECTLY during the first couploe hundred miles, or it will lack power and it will consume oil like crazy. it needs to be run hard for the first 200 miles, using regular engine oil, to allow the pistons rings to seal properly, and then the oil should be changed, and then refileld again with regualr engine oil, for the first 3 to 4K miles that you own it. after that, drain and switch to synthetic, full synthetic, mobil 1. also, a word to the wise... get rid of dexcool imediately.. it has been widely documented that it east through N* head gaskets liek clockwork.. use regualr coolant along with the gm aluminum engine collant pellets

Dexcool Eats Away At Headgaskets? I Didn't Know That.

Good luck getting the guys at the Northstar forum to agree about dexcool's potential corrosive properties. They take the attitude of GM service (you ran it low on coolant, or you left the coolant too long). You can reproduce the properties in lab settings easily. It can eat anything if it becomes corrosive. Ford had problems with non-dealers service centers installing GM coolant into their cars and it ate the impellers on the water pumps.

Seriously not cool.

My car runs only BMW coolant, from the BMW dealer.

Good luck getting the guys at the Northstar forum to agree about dexcool's potential corrosive properties. They take the attitude of GM service (you ran it low on coolant, or you left the coolant too long). You can reproduce the properties in lab settings easily. It can eat anything if it becomes corrosive. Ford had problems with non-dealers service centers installing GM coolant into their cars and it ate the impellers on the water pumps.

Seriously not cool.

My car runs only BMW coolant, from the BMW dealer.
...thats because when you mix the red with the green it becomes corrisve and is a NO NO. Not sure how its GM's fault that no-ford service centers are mixing in the wrong coolant. The green can be just as, if not more, destructive. The fact is that the Dexcool seems to be haveing cooling systems last longer with less maintanance...because of that people "forget about it" and let it get to a poor stage....ever see what happens to engine with the same green in it for 10+ years? or even 5? Yeah its ugly, just as if you don't change dexcool right it gets ugly.

Basically with a system that has had Dexcool, don't use green, or it will screw it up.

Bascally with a system that has had green, don't use dexcool, or it will screw it up.

Basically the whole dexcool 'bad' thing started from people doing the above.

Now regarding northstar reliability, it almost sounds like it depends on where you live for a good or bad Northstar, or good or bad opinions to crop up. I hear just the opposite about it up here in Buffalo, NY. From experiance my 98' hasn't had engine problems other than a new waterpump and it certainly is not babied.

Who said anything about mixing?

Dexcool when exposed to air under pressure is depleted of one of its additives, which turns into white hard deposits even on the wet side of the leak or exposure (Northstar surge tanks sometimes get it even when they don't leak. Also, dexcool vapors are corrosive even when the liquid is not. The head's the hottest part of an engine, and sees the most vapor, hence corrosion.

That's why Prestone's dexcool compatible coolant is better than the Texaco swill that GM uses.

I like BMW coolant because its boiling point's higher, as most of their cars have 100 or 105C thermostats (215 F or so).

Who said anything about mixing?
I think you did when the non-ford dealers were putting it in the system...since ford doesn't factory fill dexcool it must be mixing.

Didn't relize BMW made their own coolant.

And depending on the mix of any coolant its protection is higher or lower, all depends on what the needs are of the vehicle and where it operates.

I think you did when the non-ford dealers were putting it in the system...since ford doesn't factory fill dexcool it must be mixing. ...

No, they were "upgrading" these cars to the extended life thing, flush+fill.

I'll see if I can find the article. It was quite interesting actually, about the chemistry of coolants. I'm not saying GM Dexcool is bad, just that the earlier Chevron/Texaco versions of it had some unstable properties.

No, they were "upgrading" these cars to the extended life thing, flush+fill.

I'll see if I can find the article. It was quite interesting actually, about the chemistry of coolants. I'm not saying GM Dexcool is bad, just that the earlier Chevron/Texaco versions of it had some unstable properties.

That I did read about, but todays coolant versions of Dexcool don't show those problems.

When it comes to flush+fill you still don't get rid of all of what was in the system prior to flush and fill. This leads to chemicals in both the coolants reacting in bad ways. Basically if your car started with a Dexcool based coolant, stick with that. If it was green, stick with that, etc.

i've seen similiar problems coexisting in the lincolns,and other fords particularly the mustangs.the lincolns,especially the town cars usually burn oil and you can see traces of it comming from the exhaust pipes. looking like someone was having a bar-b cue in the rear.

Ron could you tell us abit more about your STS? Used or New? what year? etc.

Also, incase you haven't already read this, here is the answer to the oil consumption issues on the N*; its quite common, and maybe if you read this you can understand it better. Remember, these are "touring" engines and everyonce in a while they need a good WOT.:sneaky:

Here's the answer to your problem (hopefully):

http://www.cadillacforums.com/cadillac-tech.html#noil

Thanks for the website. I have read numerous articles about the Northstar being a high peformance engine but I don't feel that ihigh performance is an excuse for the oil consumption. I have a Viper and it doesn't use oil like the Northstar. The car had only 92K miles on it and I sold it and bought an Escalade with a 6.2 liter. Granted - the Northstar is a nice engine but I don't want another one. There are many engines with equal or better HP output and performance that don't have the oil consumption, water leak issues, and crankcase oil leak problems - very expensive to repair and unreliable!!

Thanks for the website. I have read numerous articles about the Northstar being a high peformance engine but I don't feel that ihigh performance is an excuse for the oil consumption. I have a Viper and it doesn't use oil like the Northstar. The car had only 92K miles on it and I sold it and bought an Escalade with a 6.2 liter. Granted - the Northstar is a nice engine but I don't want another one. There are many engines with equal or better HP output and performance that don't have the oil consumption, water leak issues, and crankcase oil leak problems - very expensive to repair and unreliable!!

I never expected to hear back from you again. Really I'm shocked. :eek: Glad you found yourself another (more reliable) Cadillac. :thumbsup: