Hi, just a quick, rather vague, question - when I start up my P38 the fan belt bits rattle or squeak for a while, until the engine drops back to a regular tick-over. I am guessing that this may be the belt tensioner but I just thought that I would ask the question anyway.

Pierre3.

Take the belt off and spin all the pulleys to see which one is rattling. If they all feel OK, fit a new belt (or fit a new belt anyway)

Richard, thanks for the advice. I have a feeling that I have to pull out the fan and cowling to get at the fan belt because on the diesel everything is covered in. But at least I have had the fan and cowling out a couple of times, just a couple of months ago to fit a new alloy radiator, so I know that I can undo everything easily enough.

I know that you don't have precise knowledge of the diesel but I am wondering whether you might just have the part numbers for the tensioner wheels ? I can find the tensioner itself, but I can't find the part numbers for the idlers fitted to the diesel. Unless Dave3d is reading this, because I saw thar he discussed the same issue with someone on a different forum, about 4 or 5 years ago.

Thanks again, Richard.

Pierre3.

https://new.lrcat.com/#!/1234/90127/90128/7124 and click on the numbers next to each one. That will show you the part numbers.

Thanks, Richard, that is perfect. I looked through RAVE but I couldn't find this diagram. Thanks for your great help.

Pierre3.

That's because RAVE is a workshop manual that tells you how to do things, not a parts list that gives the parts numbers of the bits. The one I have for Mercedes is in two sections, WIS (Workshop Information System, the equivalent to RAVE) and EPC (Electronic Parts Catalogue the equivalent to LRCat or the genuine JLR site).

I used to have WIS but, again, I did find it difficult to use, so I only used it occasionally. I guess I am not very good at reading through motor on-line manuals. I never had any similar issues reading through the big parts and workshop manuals that we used for the airport airbridges and elevator systems !!! I think that it is just what you are trained to use. Our manuals for parts were over 1000 pages, and you could be an hour looking for some specific parts. No wonder my eyesight is so bad !!

Pierre3.

I'm pleased to say that the weather stayed well enough to get the idler pulleys, the tensioner, and the fan belt changed. There was some rattling and squeaking going on when the engine was started but I am happy to say that the noises have now gone. Silence is golden !!

When I took off the tensioner I noticed that the lower rubber bushing, where the bolt passes through, wasn't !! It seems to have disappeared. I have a feeling that the tensioner was allowing the belt to run slightly loose so replacing it obviously has its benefits.

The pulley wheels seemed OK but they were very black. The bearings still seemed to be in one piece but I would think that they haven't been replaced for years, if ever !!

Pierre3.