4.6 DOHC Engine Noise ?

[Racee75]

Im reaching out to members that have experience with 4.6 DOHC engines.

I have a 97 Cobra Engine that I have just installed in my roadster and was able to start last weekend. The initial start went ok, however after idling for a few minutes it developed a squeak/whistle from the rear of the engine. This noise continues for around 5 seconds after the engine is stopped.

I have started the engine a few times trying to investigate the noise and it starts fine as the a few a few minutes the noise starts again. It sort of sounds like when you let the air our of a balloon at it make the squeaking sound but at a lower pitch.

I have video of this but just need to work out how to post it.

Anyone have a suggestion on what to look for ?

[Railroad]

Pull the dipstick and try it. That's all I got right now.

[2bking]

The continuation of the noise after the engine stops sounds like it is a vacuum leak. The dip stick, as suggested, may be the cause as well as other vacuum tube connections or ports that have been capped.

[Racee75]

Thanks for the input ! I pulled the dipstick and noise went away. Traced issue to blockage in PCV incoming air tube.