Oil in manifold?

[acewelderman]

Having problems with 3800 Buick Park Ave, slowly losing coolant from the resivoir. Diagnosed as having bad manifold(typical problem), when we pulled the manifold, we did not find antifreeze underneath(oh shit) but oil in the mainfold. What would be the root cause of getting motor oil in my mainfold? The car does not have any codes, it scans good. On a cold start, it will bark and sputter 5-10 minutes and clear out and run fine. I am just scared of the well known coolant/cracking issues this motor has and don't want to blow it up. Again, why the hell is there oil in my mainfold valley pan? Thank you so much.

[2000gpgtx]

PCV system will draw raw oil into the lower intake .. it's located in the upper plenum under the MAP sensor. Not uncommon, I'd be surprised to see one without the puddles over #2 and #5 (the lowest portion of the lower manifold) if it was disassembled prior to the catastrophic puke of the plenum which in turn floods the same recesses with antifreeze, thus displacing the oil that's normally in them. Take a scriber or some such tool and push on the EGR orifice in the plastic plenum where the coolant passages are just the other side .. will probably fall thru with a lil pressure. Also, check the ends of the lower intake manifold for seepage as the plastic of the lower gaskets rots and collapses, allowing antifreeze to escape there, too. If it's wet with antifreeze or something that looks like antifreeze .. go deeper and change them, too. The bypass elbow(s) are also a common antifreeze loss site .. without knowing the year of your animal I can't specify if there's one or two, but the more common one to fail is the highly visable one from the lower intake. Both attach to the serp tensioner. The later years (I believe 99 and up, but may have started in 98) have 2 plasic elbows.

[maxwedge]

Had the same issue with a K engine Buick in my shop, oil was migrating up thru the 2 inside corner bolts of the lower intake, took them out cleaned everything up, used rtv and problem solved, very common issue.

[acewelderman]

Thanks guys, Have a set of special "metal" lower intake gaskets coming in the morning.I will post the final results.Thanks again!

[acewelderman]

OK heres what happend.The lower gaskets were desrtoyed!The motor ate them!Found pieces of plastic gasket all thru my cooling system.Replaced them with metal felpros and put it all back together.Going to super flush radiator and replace water pump.(Im sure it ground up alot of plastic so why chance it)
Putting green antifreeze also no more DEATH cool for my cars.
Thank you again for all your help!I can run a friggin laser but have a hard time with sneeky problems like this one!

[Damnitjim]

where did you get metal gaskets ?

[maxwedge]

Welcome to AF. This is a very old thread to continue, start a new one in the future, thanks. Napa has the Fel Pro gaskets.