V6 NH Cold Start bearing noise.

[91Geoff]

Gday, got a 91 NH V6 and when the engine is cold, it makes a horrible, horrible noise that sounds like a dry noise.

Once the engine is warm and up to pressures, it purrs along like normal.

Doesnt drive like a pig when cold, drives like normal, its just noisy as hell.

Oil levels fine, not using any more than every other 3.0 on the road.

Any ideas guys? Hoping its not serious, and i dont think it is as it only does it when cold....

[mrbitchi]

Possibly an idler wheel bearing on the fan tensioner?

[91Geoff]

Good idea - but would that not ping off its head at all revs and temps?

[chippy4x4]

have you tried to isolate the area of the noise? if you get about 60 cm of garden hose and put one end in your ear you can move the other end around the engine while it is running and you should be able to isolate the problem. If you think it is a pulley then take the belts off and run the engine, see if the noise goes away. If it does put one belt back on and try again until the noise comes back. You will find the problem if it is external, if not it may be oil feed related, what is the oil pressure? hope fully this helps and the problem is a bolt on part
cheers

[mrbitchi]

Good idea - but would that not ping off its head at all revs and temps?

Not necessarily. They often make a noise when cold then shut up.

[BlueJ]

The idler pulley on my alternator belt squeals at startup, then quietens down as the engine warms up.

If it is an idler pulley you can identify it by spraying a small amount of WD40 or similar into the gap between the rotating part and the stationary part of the pulley. If the noise stops straight away, you have found the problem.

[Rendrag]

If it is an idler pulley you can identify it by spraying a small amount of WD40 or similar into the gap between the rotating part and the stationary part of the pulley. If the noise stops straight away, you have found the problem.

*grin* or just pull the belt(s) off - that'll tell you quicksmart if it's any of your pulleys