Exhaust under intake manifold

CraigLyon

Member
I've got a 1960 Buick 401 with a confusing problem that maybe one of you have seen. The engine was running perfect and then one day the engine noise was different. The engine noise appeared to be exhaust and was traced to an area under the intake manifold. I assumed it to be a blown head gasket, but after replacing the head gasket the noise remains exactly as before. Both the head and block seemed within tolerances and did not require shaving. I would appreciate any thoughts you might have as to potential causes of the problem. Please send your ideas and suggestions. Thanks
 
Last edited:
Flip the intake over and you will find a soft plug in the middle of the intake. I would bet you will find it is rusted out and the exhaust is coming from there.It is part of the intake heat system.
 
Joe T - You are a genius! You nailed the problem as we found the plug to be rusted out. The intake soft plugs were not locally available so we had to do a temporary patch. Any idea where the plugs can be purchased? Thanks again for the advice.
 
Check with :TA Performance
Their phone number is : 480-922-6807
Good Luck

PS if you have an old parts hous in your area, you might check with them. NAPA and Autozone dont have the "old " books
 
Back
Top