5.7 hemi runs but no engine vacuum

[Ronnie Hamlin]

Originally Posted by Ed Wright

That's what I was wondering. Internally leaking EGR is a vacuum killer. If it has one see if it's hotter than the intake manifold.

Monitor your IAT (intake air temp) on your scan tool data stream to see if the intake air temp is higher than your ambient air temp. Unless the exhaust is completely clogged, the engine vacumn should be near normal at idle. EGR stuck open will affect engine vacumn.