I am planning on purchasing a 97 STS, the guy im planning on buying it from said after being asked if there is anything leaking, "its normal for all Northstars to drop oil". So i am thinking its going to have a bunch of oil underneath. Is this true? It currently has about 85k miles on it. Please let me know before I make a big mistake.
08-19-07, 01:53 PM
It is NOT NORMAL for any modern automobile engine to LEAK one drop of oil. Gasket and sealant materials have come a long way, and oil leakage is a no-no from the EPA. N*'s have instances of leaks from the lower crankcase/oil pan seal, but those were a warranty fix, and expensive if not done under warranty. There have been one or two instances of oil cooler lines or seals leaking in this forum. Easy fix. Same for oil level sensor or oil pressure switch.
If it leaks, something's broken and fixable. Some N*'s seem to like to burn off the first half quart or so after a change and full oil fill.
08-19-07, 05:08 PM
Every single car I own or repair (the family's) leaks something or other. Cadillac, Pontiac, Mitsubishi, Chrysler. 2 98's, 1 96, 1 95, 1 87.
Keep in mind most vehicles might have come with a 3 or 5 year warranty from the factory, and likely were designed to hold themselves together for that long. Your 97 is 10 years old. I'd not only expect a few leaks, but a few broken things too.
Earlier Northstars are known to leak oil. As Submariner said, some leaks are easy and cheap to fix. Others are expensive. That said, they are usually just nuisance leaks.
08-19-07, 09:03 PM
I think oil pan gaskets and half-case seals are still common leak points. Just look underneath. If the bottom of the car is covered with oil stay away, or investigate it. If there just some wetness on the bottom of the oil pan and around that area then you're fine.
Don't be afraid to get the car in the air and look at things with a light.
have an oil pressure check done, I leak like a sieve from my front valve cover and some from the oil pan seal which I'm just too lazy to fix right now but will when I yank the engine hopefully this winter. You just wanna make sure the half case seal is good by checking the oil pressure, that's when I'd get nervous...
08-24-07, 06:36 AM
It is common and normal to see a leak on a Northstar from the case halves. It should not be leaking and GM has a new procedure to correct it. The new production FWD Northstars still have not implemented this procedure in the new production so they will leak at some point. The V6 uses it and they do not leak. From time to time we run across a dry Northstar that has not been repaired, but it is rare. They stand out.
We see cars that have been sealed up from a previous repair 3+ years later and NO signs of seepage.
I was the first guy at are dealer to use this stuff and I talked another gut into it after a while. I started at Crest Cadillac in February of 04. The TSB came out in Oct 03. I bet it was late 04, but probable the spring of 05 the first time I used it. Yes the math does not add up because other dealers have been using it longer than we have.
This is a very good point why We need to have imports. With out imports we would have oil leaking SBC.
Toyota built a better car from 198? to 199?. It is a fact.
They used sealer and they did not leak oil.
GM learned it is not acceptable to have oil leaks and interior door panels falling off the car. No more squeaks and rattles Except SRX's. They are normal ( I don't want to fix them so they are normal).
I don't think that Engines should burn oil, but the fact is they have to. They must burn oil to improve fuel economy. Ring tension and drag.
You should not have sludge build up in an engine. This should never occurred and if it does (Toyota) it is from dirt getting into the engine or oil puddling and burning off. This would be a design flaw.
Saying this. A Northstar should not leak. If it has 100K I feel it would be ok to have some seepage.
Back it 1990 or when ever GM started assembling the Northstar for testing it was acceptable for engines to leak. They see that is not good and the engineers worked out a plan to cure the leaks.
Caddy's Harley's Hmmmmm Imports have really changed the products
08-24-07, 05:33 PM
At Allen Cadillac ( California), the mechanics throw out the 'o' rings and use a real rubber sealant at the pan sections, etc. There's a GM part# for it, ..It looks like a short caulking tube.
Unfortunatly, when I resealed my North*, I was not aware of the 'trick', and was careful installing the new 'o' rings.
It leaks a bit. That's frustrating.... When I finished my North* install, you could eat off the bottom of the car. Now it looks crappy.