View Full Version : engine oil in intake manifold

03-10-14, 09:31 AM
Anyone experienced engine oil in intake manifold on Seville 1996? Any idea what could be faulty? Currently we have removed transmission with shifting problems. Engine has 78000miles.

03-10-14, 10:12 AM
Nothing is faulty. It's normal EGR and PCV gas deposits that settle out after the engine is shut down. Ugly, but harmless.

03-10-14, 12:28 PM
Yep ^^^^

PCV vapor deposits. Normal. Pre-2000 with rattle valve and pre-1998 with different TB piping will get dirtier.

03-10-14, 01:28 PM
When i replaced my starter not too long ago, i had a bit of a mess in the valley. And this is a "newly built" from the ground up Northstar, all new seals and gasket. I wouldnt be concerned.

03-10-14, 03:11 PM
I had the same thing in my 1998 Deville, when I was cleaning the throttle boday. Nothing to worry about.

09-04-14, 03:49 PM
Oldish thread

I am changing my starter and noticed the same thing, some liquid poured out when I turned it upside down. The inside of the intake manifold is oily/sooty as can be too. Again this forum helped out.

09-04-14, 03:57 PM
You might want to take the manifold to a shop and have them hot tank and dry it. Bolt torque is 89 lb/in - about 7.5 lb/ft. Don't crack a bolt boss or you're in the new manifold business - $275.

Back to an old, old thread - Google "cadillac forums a river runs through it".

Pre-2000 was most susceptible to PCV oil ingestion, especially if you try to keep the engine oil level at the MAX mark.

Proper Northstar oil level is here (7.5 quarts with filter) ..................................

<===== ADD XXXXXXXXXX <== OPERATING RANGE ==========oo==========================O

More info up ^^^ in the top black bar - Cadillac Technical Archive. Necessary for any Northstar owner. (CTA was posted by the engineers who developed the Northstar System and OLM)

09-04-14, 04:08 PM
I definitely wouldn't bother having it cleaned. It'll be that dirty again fairly soon. It's not bothering anything.

09-04-14, 04:19 PM
A 2001 TB should not get that bad - the 2000 and later intake manifold receives PCV dirty air into the center of the log (as opposed to right at the throttle butterfly), so with proper oil levels it should stay pretty clean - mine only needs a touch-up every couple of years, if then.

09-05-14, 10:50 AM
Thanks Submariner409 and MoistCabbage.

I put it back together before reading your comments. I didn't worry about cleaning it too much, just wiped up what I could. I'm sure it's a little dirty than most: The last 2500 miles I haven't been able to open it up at all. I'm milking bad headbolts until this fall when I'll take it over to Midwest Cadillac for repair. So I'm sure never getting above 2200 rpms doesn't help keep it clean.

09-07-14, 10:50 AM
I definitely wouldn't bother having it cleaned. It'll be that dirty again fairly soon. It's not bothering anything.

:yeah: Kind of like cleaning your exhaust system.