Whistling at low RPM

[droptop]

After two days hard driving last weekend, I notice a sort of whistling/chirping noise in the engine at idle-1100 RPM which then leaves it as the revs rise.
I first thought maybe alternator or tensioner bearing whine, or possibly water pump, but as they all have less than 4000 miles on them and also because the noise seems to disappear at higher RPM, I'm starting to think there may be an air leak in the carb or manifold.
Also, the "get up and go" when the secondary choke opens at full throttle seems to have "got up and gone" as it were with the lift I usually feel above 3000 RPM is now somewhat lacking.
Any advice for tracking down the suspected leak?
The idle has also increased by about 100 RPM but is still even, so I think the leak must be small.
All advice appreciated. Thanks

[Neil-yaj396]

I've had a rattle/chirping noise at idle for several months. It doesn't necessarily rise with the revs then disappears at about 3000. Do performance symptoms on mine though. Definately external to the crank case. I've spent ages with my head under the bonnet but to no avail.

[droptop]

Time to form a suppor group

[peteracs]

I've had a rattle/chirping noise at idle for several months. It doesn't necessarily rise with the revs then disappears at about 3000. Do performance symptoms on mine though. Definately external to the crank case. I've spent ages with my head under the bonnet but to no avail.

Have you discounted the heater fan?

Peter

[Neil-yaj396]

I've had a rattle/chirping noise at idle for several months. It doesn't necessarily rise with the revs then disappears at about 3000. Do performance symptoms on mine though. Definately external to the crank case. I've spent ages with my head under the bonnet but to no avail.

Have you discounted the heater fan?

Peter

Yes, in fact it's slightly more noticable when the engine is cold.

[droptop]

I'm going to take a serious look at my car this weekend.
I suspect it may be the carb to manifold gasket or even the main carb top assembly gasket.
It seems too smooth at idle to be the inlet manifold gasket or a leak in the servo vac. union as the brakes are unaffected.
Anyway, I'll post my findings, if any, when I'm finished.