One way is to start the engine and spray starter fluid around all edges of the intake. When you find a leak the engine RPMs will increase. Be very careful and have a fire extinguisher ready just in case. Know that any spark will ignite the starter fluid.
take it to a mechanic
Remove the intake manifold retaining bolts from your 1996 Chevy Astro Van. Remove the manifold gasket and clean the surface. Reverse the process to install the new intake manifold gasket.
Assuming this is a 4.3L engine, the upper intake manifold gasket would be between the upper intake manifold and the lower intake manifold.
is their a web site, that will provide me with the a print out for the intstalling of a intake manifold gasket for a 2003 chevy aenture.
there is no lower intake gasket, only a front and rear gasket
You either need a head gasket or intake gasket.
there is no upper intake gasket, only a front and rear
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if you had it heat high enough it very likely worped your heads and or damaged the head gasket
had a 95 3.1L V6 Lumina that would lose AF as well. Maybe your intake manifold gasket or head gasket are going bad. If there is unusual stuff on the oil fil cap or dipstick you have a gasket leak.
Upper intake manifold plenum leak/crack most likely. If its blowing out coolant then you probably have a bad head gasket.
It is between the upper and lower intake manifold. The gasket is an o-ring type.