Serpentine belt or tensioner : OM611 engine

vehicle 2003 T1N MWB 413 which I reckon is the 2.2 OM611 4 pot.

It has started to squeak on idle, suspect is the serpentine belt (or fan belt). It's a ex plod with A/C (not sure if factory fitted A/C or not as this affects the belt length I glean from an Aussie posting here https://sprinter-source.com/forum/showthread.php?t=41044&highlight=belt+611

Most of the info on this site is for the 5pot engine, can anybody help with

service interval manuals for the euro engine

info on the belt squeak such as belt tensioners (check for wobble) ?

Your help is much appreciated, great forum this...

Hiya mate, belt squeaks are normally down to idler rollers starting to pack up. I'd be inclined to have the belt off, check it for wear and tear - replace it if it's either old or showing signs of degradation. The idler and any other rollers should be checked for smooth running and (if possible) re-grease. Better and safer is, fit a new belt and rollers, they are available on the bay for reasonable money.
ATB
George

I have the same engine. The belt tensioner tends to come apart. This causes the belt to walk off the front of the pulley, and causes the squeak, squeel, sqwak. Depending on mileage, and history, best practice would be to invest in a kit, and replace the lot. Pulleys, belt tensioner and belt. Mine has rear aircon. And the belt is 6pk2265. If your belt appears to jumping around a bit at idle..... then the alternator pulley clutch needs replacing. I elected to change the complete alternator in my case.