i hav a 97 bonneville with a 3.8L non supercharged and sometimes it starts really hard and if it does start it sorta acts like its missing on a couple cylinders. and i also noticed too, it that it buffs out blue smoke for a couple seconds sometimes. the al started after i replaced the upper intake and replaced the oil to synthetic. and the check engine light is on too.

me and my dad cleaned the throttle body and the idle speed valve. while we had the throttle body off we noticed that the upper on was full of oil around each port and that the little tube in the air plenum had fallen over. wat is that little tube for? anyways i put it back in place while i had the throttle body off.

can someone help me out asap. thanx

If you changed the upper because you were losing coolant, and did not change out the lower intake manifold gaskets, that could be the problem. Check the oil immediately for evidence of coolant contamination. If you find coolant in the oil, drain the oil right away and get to those LIM gaskets.

Codes can be checked for free at O'Reilly and Autozone

Oil sitting under upper intake is normal

Little pipe is stovepipe that conveys hot exhaust gas past plastic upper - You should install a reduced diameter stovepipe to provide a little insulation to protect the new upper.

Read this: http://www.bonnevilleclub.com/forum/...e=article&k=38

Bill, I think he'* talking about the plastic PCV tube, not the stovepipe.

I agree that if the upper comes off again, a Reduced diameter stovepipe should be installed.

why would i hav to reduce the size of the stove pipe and where exactly is the oil coming from?

The reduced diameter stovepipe will prevent your upper intake manifold from eroding from the heat, breaking through into a coolant passage, flooding out and possibly hydro-locking your engine, or rusting our your rod bearings like dozens of L36 cars here already have suffered.

I have some pics I need to upload of the EGR stovepipe area on an L36 upper intake manifold manufactured in 2002. It'* already starting to fail.

The oil is coming from the PCV system. Positive crankcase ventilation. As combustion gasses leak by the rings (small amounts) they pressurize your crankcase, resisting the downward motion of the pistons, and reducing efficiency. The PCV valve redirects these fumes, including some oil mist, back into the upper/lower intake manifolds where it can be burned off.

Please read the techinfo article linked above. It will explain the problem and the solutions clearly for you