Northstar Engines and System Technical Discussion Discussion, intake and top cover 94 Seville STS 4.6 in Cadillac Engine Technical Discussion; I just bought a 1994 Seville STS with a 4.6 it has a hesitation the check engine lite is on ...
I just bought a 1994 Seville STS with a 4.6 it has a hesitation the check engine lite is on I have a code p046 I was reading other post and was trying to check for a intake leak so I took off the top cover looks like there some oil in there (not a lot) so I tried to start the engine and it revved up real high I was trying to check for a intake leak is this normal I red in another form you can run the engine with out it but not recommended can some one tell me if this is the right way to check for a leak I was going to use carburetor cleaner . Any help would be appreciated thanks Tom
Automobile(s): White Diamond '03 DHS (with floor shift)
Re: intake and top cover 94 Seville STS 4.6
The oil you see in there is normal. It is a combination of crankcase gases from the PCV and exhaust gases from the EGR. NEVER start a '93/'94 Northstar with the manifold cover off. The engine will runaway unthrottled as you experienced and bounce off the rev limiter. It's just like flooring it in neutral. Not good. Check for a vacuum leak by spraying Brakleen or carb cleaner around the manifold cover seal and listen for an RPM increase. While you are in there rod out the EGR passages aka "mouse holes" and clean the TB.