Strange “click” when I shut off engine
 

Sometimes it Clicks right as it shuts off, other times it’s 1-2 seconds later? Any ideas? I can’t seem to track it down...

Recirc valve needs rebuilt.

When my BOV needed new seals I only heard the clacking noise when lifting off the throttle. Engine is usually at idle when you're shutting off the ignition, doubt the recirc. valve is displaced at that MAP.

OP: Can you characterize the sound more? Is it a quiet click noise, like a relay perhaps, or does it sound like a hammer tapping something? Does it happen any other time? From the engine bay? Under the seat? Behind the dash?

It the sound to the door as your passengers bolt from the car?

Thanks, I don’t hear it any other time the sequence is like this:

Parked car idling
Turn off key
Loud “sharp” Click/snap noise (immediately or 1-2 seconds later)
I just had an issue where the starter wouldn’t engage, Could the starter selinoid do that? I assumed no, since it should be disengaged once the car is started

Oh and the noise is from the rear of the car, engine area

Where do I get the gaskets to replace on the BOV?

That's when the delayed action CDI relay would power down, maybe its that.

Doubt its these, but here you are...930 110 149 00 (2ea needed)

The recirc valve is different from a Bov. If the seals are worn out, it clicks a second or so after you turn off the ignition. Easy to replace and sold on here.

The recirc valve is just a piston held down by a spring, but when under high manifold vacuum it's pulled open against the spring tension. When vacuum goes away....such as stepping on the gas or turning off the motor, the spring tension pushes the valve back to its resting seat. Clunk, if the gasket at the end cap is worn. Not only is it a gasket, but it also serves as a soft "landing point" for the piston to contact. Most noticeable sitting at idle, and quickly on-off the gas....you'll hear it clunking.

Thank you all, I just ordered the new gaskets, is there any performance impact with the worn gaskets?

i couldn't tell any difference other than that annoying click went away.

Depends how dry rotted the old ones are. They could become hard to find vacuum leaks at each end of the recirculation valve cylinder if they're really bad.
After 20 years of heat cycles and whatever is in the air these days they get to be like old pounded out candle wax.

Be careful while removing the four 10mm wrench size nuts. There's a long compressed spring inside the recirculation valve piston that's gonna make it fly out if you don't hold the end piece in place while removing the nuts.
Lube the spring with grease and the piston and cylinder wall with motor oil while putting it back together. Grease will probably work on the piston and cylinder wall instead of motor oil but it might slow down the movements of the piston a little after a while or maybe not.

Working on this next, can I replace the bushings with it still on the car/in the engine? I know I need to take off the intercooler, was hoping I didn’t have to take too much off

It's easy to remove after the intercooler and air cleaner are out of the way. It would be a big hassle to try to service it while still bolted to the intake manifold.

I don't remember but it may be impossible to get to the four 10mm nuts on the back end of the valve cylinder closer to the firewall if it's still on the motor.

That's how I've done it in the past. Pretty tight clearances, but can be done with patience, like most things 930.

Check out this thread: http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/394693-bye-bye-clicking-sound-slownrusty-pictorial-bov-housing.html