Whistling Engine

[Kiloengineer]

I have a strange whistling noise coming from the front of the engine, I can't decide if it is the dynamo or the water pump. 2.25 petrol. I tried oiling the rear bearing of the dynamo, no difference. The noise goes away when accelerating the engine, but when the throttle is released it comes back and is worst at idle. Is this a known symptom? Thanks for any ideas.

[albersj51]

Intake or exhaust leak?

[SafeAirOne]

I'd get a mechanic's stethescope and determine exactly where the noise is coming from. The repair will be obvious once you pinpoint the source of the noise.

[mearstrae]

Sounds like a vacuum leak, as the noise increases when vacuum is highest. Spray along the intake and carb base lightly with water, if it quiets down and/or the idle goes up, you've found where it's leaking.

'95 R.R.C. Lwb
'76 Series III Hybrid 109
'70 Rover 3500S

[Kiloengineer]

I should try to post a sound clip, it sounds like a mechanical rubbing of some kind, but I will try looking for a vacuum leak and also use some kind of makeshift stethoscope and let you know what I find.

[gudjeon]

The diodes in an alternator can give a slight whistle noise at idle.

[I Leak Oil]

I agree with Safeairone, do some more digging on it. Engine noises and driveline vibrations are tough to figure out sometimes, nevermind over the internet.

[Kiloengineer]

Just a quick update to let you know I appreciate all of your ideas but I have not had time to work on this problem, turns out the Rover is the most reliable of all my cars! Currently working on the BMW 328i, VW GTI and Volvo 240. And of course the Jaguar is just taking up space in the garage.

[LaneRover]

I had a whistle like that, at idle there was a high pitched whistling sound that went away when I accelerated. The carb was just a tiny bit lose where it is attached to the intake manifold. When I accelerated it closed the gap.

[Kiloengineer]

So I finally figured out the source of the whistle, in case anybody is interested. Just as LaneRover suggested is was a leak at the carburetor attachment. I could get it to change note by tightening the nuts (Zenith carb), but it would not go away. So I used some non-hardening gasket sealer (forget the brand but it is british) and the noise is gone. Thanks again for the help.