Strange starting noise
 

1994 Volvo 850 210k miles (petrol, 10v non-Turbo)
Any idea what is making this sound:

https://www.youtube.com/watch?v=y0_74DlRKIQ

It seemed to start happening not long after I replaced the timing and auxiliary belts.
I have started the engine with the auxiliary belt removed and the sound is still there.
It always occurs when started from cold and only rarely when engine is warm.
The engine runs very well and there is no noise at other times.
The starter was replaced by Volvo (ie with a new one), seven years and 32k miles ago.

Any help much appreciated.

Sounds a bit like the starter gear is sticking...
But as it's only started since replacing the belts, have you checked that the timing belt guard plate, behind the crankshaft pulley is not rubbing?

I did wonder about something rubbing on the timing belt but surely that sound would be there at other times? This only occurs on starting.

I would suspect the starter motor isn't disengaging soon enough. As it only does it when cold it could be heat differential between hot and cold conditions making the starter pinion stick or not.

Wild guess, but maybe worth thinking about. Is the Air con involved (on/off etc)?

Steve

Thanks but I don't have air con.

Hi,

OK and sorry just noticed
"I have started the engine with the auxiliary belt removed and the sound is still there." which would mean no a/c compressor involvement.

If it is a manual you could bump start it (ie not involve the starter). That would be a fairly conclusive indication of starter/pinion problems or not.

Since your starter is relatively new, the starter pinion noise may be being caused because the teeth on the edge of the flywheel are messed up.

On V70s (I don't know about 850s) I am pretty sure you can see the teeth if you remove a 3 inch metal cover plate near the bottom of the junction between the engine and gearbox.

If those teeth are OK then changing the starter would probably be the next step.
A used starter wouldn't cost much.
If they are messed up, then I think that would be a much bigger engine-out job.

Not sure why occurring less when warm.

HTH
Steve

Thanks for your suggestions. I will try that push start idea. I would hope the teeth on both the starter and flywheel should be OK as both have been replaced albeit a little while ago now (I also replaced the clutch with a new Volvo one).

Sounds like the pinion is sticking. Could be caused by a build up of dirt on the pinion gear or damaged teeth on the pinion or flywheel teeth damaged

Clutch release bearing?