Coming home from work - took the scenic route (through moor land with very evry good driving roads! http://www.saabscene.com/forum/images/smilies/fawlty.gif )car was flying.....
A pop, then a loud whistle. Couldnt see anything loose......gradually got to the point of very rapid change of idle speed. Eventually found that the rubber gromet(sp?)that goes into the intake manifold, the one with a vac hose to fuel regulator.....was gone! Completely gone.
Limped home(just) and put a new gromet in:seems fine now.....
Question. Will I have done any damage? What caused it? Just rubber that perishes over time?
Has anyone else encountered this?
Scared me senseless......thought car was gone!
Oh well...........

Hi, Paul.

I have heard of this happening before and yes, I think it happens when the grommets are old. If there is more than one grommet, it might be a good idea to replace the others as a precaution.

The engine will have ingested a very small amount of unfiltered air, but I doubt it will have been significant enough to cause any damage.

Mine went through a phase of doing this! After I replaced a split dump valve, I suppose the boost pressure was higher and it found all the weakest points in the system. It actually blew one of the press-fitted copper pipes out of the throttle body! http://www.saabscene.com/forum/images/smilies/eek.gif I also lost one of the gromets on the inlet manifold like you. I replaced them all, including the rocker cover breather one, just to be sure. They were only a couple of quid each IIRC, from a dealer.

P.S. I agree - terrifying noise. Always happened when you booted to overtake a lorry too, just to add to the fear.