Tropical bird sounds

[tay]

I have a 1973 model 914 1.7 (fitted with two twin choke carbs in place of original injection) which has suddenly developed a loud squeaking/screeching sound that can only be described as frightened tropical birds. This only happens at idle or when the engine is not under load, and when normal running temperature is reached (it does not happen when cold). I have changed the fan belt, and run the engine without fan belt (to eliminate the alternator), all the tinwork seems to be tight, and the clutch is ok (i.e. still screeching with clutch in or out). The car runs fine and uses no oil. The noise seems to be coming from the passenger side of the engine compartment, though it is difficult to pinpoint. The sound is consistent with the engine pulsations. Any ideas as to what could be causing this?

[Dave at Pelican Parts]

Some carbs squeak. There are specific gaskets to combat this, but I don't recall the details. (I'm not a carb guy myself.)

Check for vacuum leaks; the fact that the sound starts when the engine warms up makes me think it could be a leak.

--DD

[tay]

Thanks Dave. Problem solved; leaking gasket between carb and manifold acting like a reed.
Regards