When I shut my engine off I hear a hissing noise. Don't hear it all the time so today I had it idling in the driveway and when I shut it off I went under the engine to listen for it and it is coming from the front timing cover crankshaft seal. It lasts for about 3-5 seconds at most. Getting a little oil from the front seal area also, but not all the time. Is this common or do I have underlying issues with this engine?? It now has about 1200 miles on it. Could it be that the seal is bad or is this thing building excessive crankshaft pressure or is the sc causing pressure inside the crankcase?? Thanks

 

Sounds like you need to do some work to your crankcase breathers. Its breathing through the front seal cause that and the rear main are the easiest seals to push out.

 

+1 on Blu man.
Not sure what your PCV set-up is but it's not allowing enough pressure to vent.

 

Or its putting too much vac on your crankcase and it does not have a sufficient fresh air source. Either case appears the same.

 

catch can and revised PCV time...

 

or no pcv and valve cover vents

 

I was having some of the same issue except it was pushing our my valve covers. did a -10 bung on each valve cover into a vented catch can and no more issue.

 

Ok, so do I need to replace the seal??? It doesn't do it all the time. Far as the current PCV set up I have the stock PCV valve in the drivers side valve cover and on the passenger side I have a hose with a one way valve(PCV valve) in the intake tube that is on the intake side of the supercharger. That is what Vortech has in their instructions. I never had this issue with the other engine. This has only done this since the new 402. So new valve covers with breathers or a catch can would solve this??