engine noise / timing belt cover end / any ideas?

[eclipse1501]

I fitted the engine the cover back a week or two ago after having it painted (thread:http://www.nsxcb.co.uk/testvb/showthread.php?t=6119&page=2) but since i seem to have a whinning noise coming from the timing belt cover end. The belt was changed about 18 months back. The noise seems to run in tandem with revs getting higher pitched with higher revs. Its just noticeable at idle. Its not the alternator bearing as Ive had the old hosepipe out to try and locate the source. Seems to be lower down bottom end directly under alternator - around area of the bottom pulley (whatever that runs) directly below alternator.

Any ideas, or if intervention may be required?

[Sudesh]

Have you ever changed the Crank Shaft pulley?

Alternator belt runs to that, and then a belt runs from the pulley to the AC compressor.

[eclipse1501]

Have you ever changed the Crank Shaft pulley?

Alternator belt runs to that, and then a belt runs from the pulley to the AC compressor.

I never changed it when I had the timing belt done. Since then having read a few warning threads I wish I had. The noise seems to be in that neck of the woods. Thanks for the tip Sudesh.

PS. I noticed when i go over a speed bump and slow right up, holding the car on clutch control, the sound disappears momentarily. Strange one. But worrying!

[NSXGB]

Very difficult to diagnose without seeing or hearing but...
Did you change your a/c or alternator belt recently?
When the TB was done, was the tensioner pulley & spring replaced?
You know that the crank pulley can be changed without disturbing the timing belt, don't you?

Disconnect your a/c and alternator belts and see if the noise is still there. If it is it sounds like you will have to remove the TB cover for further investigation.
Have a look at Kaz's Health Check thread as it gives some pointers on diagnosing crank pulley failure.
Sounds like you should get it done anyway for peace of mind.

[Nick Graves]

You've irritated it!

The likelihood is you've either slightly misaligned the cover so it rubs, or overtightened the belts. Alternatively, re-installing a part worn belt "backwards" might cause a harmonic.

[eclipse1501]

Very difficult to diagnose without seeing or hearing but...
Did you change your a/c or alternator belt recently?
When the TB was done, was the tensioner pulley & spring replaced?
You know that the crank pulley can be changed without disturbing the timing belt, don't you?

Disconnect your a/c and alternator belts and see if the noise is still there. If it is it sounds like you will have to remove the TB cover for further investigation.
Have a look at Kaz's Health Check thread as it gives some pointers on diagnosing crank pulley failure.
Sounds like you should get it done anyway for peace of mind.

Got the TB/Cover/Wpump kit from Dali 18 months back but no tensioner/spring in it so they were not changed. The crank pulley was never changed either. I think the ac and alt belt off would be a good start but seems inevitable it will be one of the former as you say!!

As Nick says something has been irritated alright!

[unclebob]

way out of date sorry