Hello

I have a 1996 Cadillac Deville that I bought in 2003. I have put 50000 miles on the vehicle. I purchased the car from a friend to settle his mother's estate. I have to say that the Northstar engine is awesome! I never would have believed that Detroit could produce such an engine!

The car has 120000 miles and is starting to have some problems. I have oil leaks at the rear main seal and the lower engine block joint (at the crankshaft). The dealer quoted $3500 for repair. I use about 1 quart of oil every 800 miles. Anyone have an opinion on the oil usage. I am not going to pay the dealer $3500, so my only recourse would be to continue to drive the car as is or attempt to repair the car myself. I have tackled large automotive tasks before, but I have never removed an engine. I am a Mechanical Engineer and am confident that I could repair the engine myself, however, trying to remove the engine from the vehicle and get it on a stand gives me the "shakes".

Also, I have an annoying hydraulic lifter tap. It is noticable with the engine at idle (warm and cold). Does anyone know how to isolate a malfunctioning lifter? I have tried the mechanics stethoscope, but cannot pinpoint the noisy lifter. At almost $50 each for a lifter, I don't want to replace any more lifters than absolutely necessary! Is there a benchtop test I can use to isolate the noisy lifter?

Any help would be greatly appreciated.

This forum is very informative. I learned a lot of information searching the discussion groups.

Welcome,

Thanks for joining the forum! I will move this thread to the Deville section for better visibility. Good luck.
Paul

Go to the top left of this page, click on Technical Archives and read up on oil consumption.

Ranger

Thanks for responding. I have read-up on oil consumption. From what I read, "normal" oil consumption is anywhere from 1 qt every 1200 miles and up. I don't really know what I am consuming and what I am leaking out through the rear main seal and the crankcase joint. All I know is that I add a quart about every 800 miles. The usage has been steady over the past couple of years (the leak has been going on that long). I guess I shouldn't be concerned unless the oil usage rate increases.

Do you or anyone know how to identify a noisy or collapsed lifter? I am pretty sure I have a lifter tick, but I have not been able to isolate the noise with a mechanics stethoscope.

Anyway, thanks again for responding! This site a a great resource!

I am really not sure on how to check the lifter other than the stethescope. Short of removing the cam covers, try a can of Marvel Mystery Oil or a qt. of trans fluid in the crankcase. Maybe that will free it up.

"Marvel Mystery Oil or a qt. of trans fluid" Ranger could you expand on this, is MMO anything like slick 50 and what do you think of MMO and SL50 for engine longevity......Jim

Slick 50 is snake oil.

MMO has been around for years and is basically a solvent. It is pretty good at freeing up sticky lifters of yesteryear, but with todays oils, I really don't know if there is tha much of a need for it, though it is still sold.

Trans fluid likewise is another old mechanics trick. It is very high in detergents and is supposed to do a good job at cleaning, but again, with todays oils it should not be needed. Years ago (early '70's) I used to put 4 qts of oil and 1 qt of trans fluid per oil change.

I would only use either today as a lasst ditch effort if I thought I had a sticky lifter.