I drove the Corvair to work on Saturday. With the exhaust fixed, the engine is pretty quiet. But there is a rattling noise that happens only when the clutch is released. But it doesn’t happen when accelerating or if I slightly depress the clutch pedal. Bob St. John thinks it might be the throw out bearing. But Corvair Underground said otherwise.
THE ENGINE MAKES A HORRIBLE RATTLING NOISE – yes, I realize that you think you have rod bearings going out but this is rarely the case. First, remove the fan belt and run for a short period of time. If the rattle goes away you can be pretty sure that the blower bearing is bad. That not being the case the next thing to suspect is a bad flywheel. A positive test is to let the engine idle in neutral and slightly depress the clutch pedal – if the rattle goes away or changes then you have bad rivets in your flywheel and it must be replaced with a new bolted unit Sometimes there is no rattling but a lot of vibration.
The funny thing is that I was able to drive home on I-90 Saturday evening and keep up with traffic (60-65 mph). So, it can’t be that bad. The other issue is that the car stalls at traffic lights. I tried to adjust the idle myself but couldn’t figure it out. So, I think I will have to take it back to Bertone’s to see what he can do.