I have a 99 sucks edition, 130,000 miles. the fuel pressure regulator was replaced due to a recall on the old one, yet the thing still blew up! upper intake plenum blown in half due to backfire situation. Was starting it and BOOM. Blew the oil cap about 50 feet in the air!

The car has been sitting for a month now untouched since it happened. I travel for work and havnt had a spare bit of time to mess with it.

Im wondering, if coolant got into the cylinders and its been sitting this long, is my engine trashed? I read something about the bearings getting ate up with coolant or something and it scared me.

Also, whats the cheapest source for a new plenum?

And how likely is it that it messed up the map sensor or blew the lower intake gasket?

Thanks for your help!

Take a look at this web page

NAPAONLINEŽ

There appear to be two aftermarket replacement intake manifold sets there for your year.

I did mine a couple of years ago with a Ken-Co manifold, but they do not seem to make one for a 99.

I change my upper intake manifold about two years ago and it wasn't that difficult.

Shop 1A AutoŽ for Pontiac Bonneville 3.8L 231ci Intake Manifold for GM 3800 3.8L 231ci NON supercharged 1995-03 for your Bonneville

It'* recommended that you change out the lower intake manifold gaskets.

The way things are situationed I'd say you are probably fine. The amount of coolant in the upper and TB isn't enough that it should have gotten into the cylinders.

It takes quite a bit to fill the LIM and then overflow into the cylinders. There'* at most a full cup in the uim and tb.