Water pump or jackshaft noise

[follman]

I have a loud screeching noise coming the engine. Its not belts etc but sounds like its from the middle of the engine, I have removed the carbs and replaced the rubber O ring seal to the manifold but the noise is still there.

Is there anyway of telling if this is the water pump or jackshaft..........maybe bearing? I was thinking about removing the pump and then running it briefly to see if the noise disappears?

I have sprayed brake cleaner around various gaskets and yes I have several small leaks but the noise remains the same.

Any advise please, I am not that confident stripping the engine down to jackshaft level.

She is MK11 1976 with original engine on Hayling Island

I have recorded the the sound but could not upload here

Thank you

[wilf]

Try up-loading it to Youtube and giving us a link?

[follman]

Good idea thank you

[follman]

You Tube link

https://youtu.be/bUrhWqMM8n0

[RNF]

Try a mechanics stethoscope or just a long screwdriver up to your ear against the water pump and other bits with the engine running

[Mark S]

Are you sure it is the engine and not the gearbox? I've heard a BW35 auto gearbox screech like a banshee in neutral.

[Lingen]

Definitely nothing to do with the jackshaft or water pump in my opinion. My alternator makes a noise rather like that when it is charging?
Mike.

[follman]

Its an auto and in in park, also makes the noise while driving. I will try to listen with a screwdriver on the alternator tomorrow but it I am almost sure its coming from thje carb area.

The suggestions are appreciated

[flying farmer]

Does the noise stay constant or does it vary with revs/load?
More difficult to tell on an auto, but if it is a vacuum leak it will disappear when full throttle is applied, a local member had this problem a few months ago.
Viscous couplings failing make a variety of squealing noises which always seem to come from the centre of the engine. See if there is any wobble in the bearings when you try and rock the fan blades.
A friend had alternator bearing failure (non Stag), but it sounded like it was coming from the centre of the crank. That was diagnosed with a screwdriver stethoscope
Neil

[flying farmer]

Does the noise stay constant or does it vary with revs/load?
More difficult to tell on an auto, but if it is a vacuum leak it will disappear when full throttle is applied, a local member had this problem a few months ago.
Viscous couplings failing make a variety of squealing noises which always seem to come from the centre of the engine. See if there is any wobble in the bearings when you try and rock the fan blades.
A friend had alternator bearing failure (non Stag), but it sounded like it was coming from the centre of the crank. That was diagnosed with a screwdriver stethoscope
Neil

[follman]

The noise varies with engine revs, my car doesn't have a viscous coupling. Going to the screwdriver stethoscope this morning

[richardthestag]

Disconnect the kick down cable from the carb pedestal, this should take the trigger for the auto gearbox pump off, does the noise go away at idle? You can then gently pull on the kick down cable and see if the noise comes back again as the front pump engages.

When my BW35 started to fail it made a lot of odd noises which my load auto specialist told me were the front pump.

Another option, I had the alternator pulley disconnect from the fan dish behind it, as a result the fan dragged against the pulley and made a hell of a noise

[follman]

I have disconnected the kick down cable.......no change.

I have a pipe to the alternator but its still sounds like middle top of engine.

[richardthestag]

I have disconnected the kick down cable.......no change.

I have a pipe to the alternator but its still sounds like middle top of engine.

Ok, maybe an induction whistle?!? Use a can of easystart or something like that, spray it around the base of the carbs and listen for an increase in revs. be careful, it is flammable.

Assuming that the vacuum advance pipe is connected correctly, is the module on the distributor working? With the engine off, remove the pipe to distributor at the carb end and you should be able to suck on it but only just. Certainly you should get to a point where you can no longer suck as the vacuum advance is fully advanced, if you can continue to suck on the tube then the vacuum advance unit is holed. Might even be worth disconnecting the tube it to see if it is the vacuum advance that is making a racket.

Are both carb pistons rising up a little when you rev the engine, remove the elbows and look straight into the carb throat

Good luck, chances are it will be something cheap and easy

[richardthestag]

Also check the two breather pipes from the RH cam cover to the carbs are intact and have no holes, these can make a din, though not quite as loud as yours