Expert: Rob Painter - 4/10/2009

Question
Hi, i have a cadi deville 98 vin Y eng northstar 4.6
the thin is that i had the transmission rebuilt; since the engine was up and the trany out, we could see the oil leak (before starting the rebuilt trany we found lots of oil on the parking lot) the mechanic said it was the crank shaft seal, so he changed that, however the leak seems to come from the upper side of the engine crate above the oil pan, i am not sure how to explain this, but my question is since the engine is already pulled and they have not placed the transmission in place yet, why not change any gaskets that need to be replace i guess this will be a good time to to it. the mechanic does not want to do it
can you give me some light? the rebuilt trany it would be a total waste of money if i have engine problems
thank you for your help! Liliana

Answer
Hello,

Your question makes sense to me and I don't know why he would not repair oil leaks with the engine out. He may want additional dollars for parts and labor and that's fine, but it makes absolutely no sense once the engine is out not to take care of these problems. Gaskets are no longer used and everything is sealed. The problem is that after time, bolts come loose from expansion and contraction. The easy way to fix, like the valve covers is to tighten the bolts, but the correct way is to remove the valve cover, intake, whatever and reaseal. With the engine in the car, this can be costly.

I would be concerned because he does not want to do this at this time. If he is capable of rebuilding the trans, why can't he fix the obvious problems on the engine?

Everyone used to brag about the Northstar and how great it was. Yet, from my experience, I have always known them to be oil leakers and oil burners.

My previous girlfriend had a 2000 Deville. Every 400 miles she burned 2 quarts of oil.


Cadillac in my opinion has never made good engines except for the 368 CU 4-6-8. The problem with that engine was the 4-6-8. We would just disconnect this function and run on 8 cyl.

The 4.1 was either good or bad new. It either had a factory knock or it didn't. I have 2 good ones.

The 4.5 was the same, either good or bad as was the 4.9 and then came the northstar. I just gave you a 20 year history of Cadillac engines. You would think a luxury car that has been around for so long would at least have a good engine.

If the engine is out, demand he repair the oil leaks now or have him get someone in that can, because once the engine is reinstalled, it will cost you plenty to repair.

Rob