Hi, my 1997 Grand Prix Gt had its upper intake plenum replaced at Pontiac Dealership about a year ago for the simple fact i heard it was a good idea to do so becuase of being know for its notorious failure and gasket wearing issues. Now my grand prix is loosing quite a bit of coolant and its not leaking anywhere. I checked my oil and it doesn't seem as if coolant is mixed. After researching, many people state they have had similar problems but said that if it was the lower intake plenum in which i have not replaced usually you would be able to see it leak from underneath somewhere and that it usually leaks internally if it is the upper intake plenum. I am now lost. My question is, could it be the upper intake plenum even after getting it changed a year and less then 12,000 miles ago? Could it still be the lower intake Plenum, even though i don't see any fluid underneath? And finally, could it possible be a head gasket leak? What could it be?
Mar 3, 2009 at 1:16 PM