[Vlad_II]

Hello. I am new here but a long time 3800 owner.

I have a 2008 Buick Lacrosse with a 3800 Series 3. It has sat for a bit due to running a bit rough on start up and not going over 3500 to 4000 RPM. So i figured it is an issue with the crank sensor. So I swapped the crank sensor and the cam sensor (while I was in there). Started it up finally today.. It runs rough then it equals out and seems ok. But won't get into the higher RPM range still.

I pulled the dipstick and saw some water in the oil. A little of the old chocolate milk.

This is reminding me of the 98 Buick Park Ave. I had with the 3800 Series 2 and it did the plenum leak and filled the engine with coolant. I was lucky it didn't bend anything. A new plenum and gasket fixed it after we got the coolant out. Put another 50k on her before I traded her in.

Now that my current series 3 has the metal upper intake plenum. I would image an intake plenum seal on these can still go but I thought they remedied this. Do these still have intake gasket issue? Or am I looking more at a head gasket.

Thanks!
-Ed

 

[dezldave961]

All 3800 2&3's had the plastic lower intake gaskets that eventually need to be replaced with the aluminum ones released by AC Delco ~4yrs after 3800's ended production.

While these can last very long, you have to ensure the couple of failure points like this are addressed before too long.