Questions and Answers

Pontiac Bonneville Intake Plenum Q. Dear Vincent, My wife drives a 1998 Pontiac Bonneville SSE with a 3.8 liter V-6, no supercharger, with 80,000 miles on it. We intend to keep it a long time. She drives about 60 miles a day round trip, and she's losing about a cup of coolant every day. Our regular mechanic, Ralph of Ralph's Auto Service in Anderson, IN says it shows tracks of leakage at the plastic plenum atop the engine. He says this happens a lot with this plastic plenum.

Since I have to have all the intake gear torn down, would there be any advantage to placing the plastic plenum with a metal one from some aftermarket firm such as Edelbrock? This car is out of warranty. We have no need to make this into a hotrod, but we don't want this to happen again at 120,000.

Thanks,
Yours truly,
AskNott

A. I'm not sure if there is an aftermarket part out there, but you should be okay with a factory part. I would also replace the lower intake manifold gasket as well.