my 98 corvette when you pull off oil filler cap, has major sucking trys to die on 1998 Chevrolet Corvette

also starts a squeeling noise after driving for 10 miles let it sit wont squeel not the belt or pullies. if you put your hand or cap back to valve cover it sucks it down(hard)intake gaskets have been replaced

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have a smoke test done to find vac leak and what is the vac readings while at idle. how many inches of vac and does needle bounce