Again with naming sounds...

[nxski]

I've been dealing with way too much guesswork on the part of mechanics today and I'm getting really fed up with it. Basically there is a sound like a bolt sliding around in a metal bowl coming from my engine. The three suggestions are as follows.
1) fan bearing
2) fan clutch assembly
3) water pump bearing

Thoughts? New suggestions?
The bolts holding the fan in place have been tightened and the fan doesn't seem to have any play (like it did before).

Thanks in advance

[yojimbo]

AC idler, just take the belt off and see if it goes away.

Mine makes a noise now, as the bearing has play, it made a worse noise before when it was loose and angled over and the idler was scraping on it's bracket.

[legionnair]

Make sure your crank pulley is tight, it is very hard diagnosing a described sound

[yojimbo]

Make sure your crank pulley is tight, it is very hard diagnosing a described sound

On that score, make sure it hasnt de-laminated and is falling apart!

[nxski]

I know it's difficult to diagnose, I'm more looking for some suggestions which I will check before going all out and replacing my water pump and timing belt.
Thanks again, I appreciate all the responses!

[yojimbo]

It won't be the timing belt, the balance belt tensioner will fail long before it does!

[nxski]

I dontthink it's the timing belt, I would just replace it if I was getting in there to replace the water pump anyways. Sorry for the confusion.

[jessef]

Make sure your crank pulley is tight, it is very hard diagnosing a described sound

On that score, make sure it hasnt de-laminated and is falling apart!

x3

your description sounds like mine when the pulley went. had to put it on a hoist and check it from the bottom.

if it is the pulley. get it fixed asap as it can be devastating to the engine if it's spinning inside or the key shaft is worn.

[nxski]

Thanks, I'll check that out ASAP

[redmond]

X4 on the crank bolt - and no driving until yo do! I couldn't place my "sound" for quite a while (checking all the belts and pulleys - other than down at the crank) and finally had it back off and power steering go to know something big was up. Wrecked the end of the crank and needed to have all that out and replaced. Yikes!

[thedjjack]

I would pull all the belts and check the crank bolt X5..

If the bolt and pulley are fine...I would run with no belts on and slowly add belts to see which accessory adds the noise (turn off motor before adding more belts )....

[nxski]

Sounds line a good plan! I'm planning to replace all the belts anyways. As soon as the glow plugs are sorted out I'll start on this. Mardy seemed pretty certain it was the water pump bearing but I'll replace that with the timing belt so that's an easy check as well.

[Manitoba deli]

I installed a used engine in an l300 for a friend last winter, and there was a strange jingling/bearing noise I could not locate in it. Just finished changing the rocker arms and cam for him on Saturday, a roller fell apart on one of the rocker arms and slightly marked the cam. Anyways, noise is now gone, I'm quite sure it was the roller making the noise while it was starting to fail. I had first checked everything you've listed when trying to locate the noise and still could not find it. If they turn up nothing for you, I'd now say pull the valve cover and check the rollers.

Jason

[nxski]

Thanks for all the options, I feel confident we can determine the cause.

I had a valve adjustment done recently, is that not something the mechanic would have noticed?

[yojimbo]

If you are replacing the timing belt, and I'm sure you know this, you must replace the balance belt as well, and both tensioners. Otherewise all that will happen is the tensioners, probably the balance belt one, will fail soon anyway, having the same effect as a belt failure.