Idler on aux belt on my 115jtd sits off the belt slightly...(belt came off the other day)
Im hoping this was the cause as ive a new idler ordered with everything else...however there appears to be no adjustment in or out understandably on the idler pulley...about 5mm of it sits to the left of the belt as you look in at engine bay...leaving a good portion of the belt with no tensioner on it to the right.
Surely this isnt right...but there is only the idler and a washer behind it...the washer is about 5mm thick, im wondering if this is the wrong washer??

Can someone have a look under their 115JTD bonnet and confirm the idler meets the belt properly...tensioner looks OK but i wont know for sure till i put the new belt on.
Cheers
Marty

Sure it's not bent? That happened to mine causing the belt to break. Tensioners are pretty cheap.

A common reason for the aux belt coming off is a knackered idler puller, and the usual symptom of a knackered idler puller is that it sits at a slight angle relative to the engine, so the belt doesn't sit on it square and is forced off centre. By the sounds of things, you can tick a few of those boxes.....

Is the belt squealing? When the idler went belly up on mine, the first thing that alerted me to it was a squealling for a few seconds after startup, which got worse over time.

Snoo it ain't bent...it's the idler just has a bolt going through it..it just seems to be sitting too far away from the engine.
I'll know more I suppose when the replacement comes!!

Widemouth it may have been sitting at an angle but as I've it off now I can't see.
But as you can imagine the idler would have been loaded on one side more than the other and that may well have kicked it of..it was never squealing. No warning signs!!
If one of ye could look at yere idler and comment back if it is sitting centrally on the belt that would be great.

Have parts coming from 3 locations fir the repair job!!..doin the timing belt aswell.
Marty

Carefully check the tensioner wheel. It has a tendency to 'soften up' around the bearing and can sit at a slight angle.

New parts just came.

New idler has a much smaller washer behind it than the one that was on it which will place it in the right position. Plus the idler is a good 2mm wider..or more like the old one is 2 mm narrower due to wear where the belt was hanging over the edge of it.

So at least I have a plausible reason for it all going wrong.
Fair play to shop4parts. First time using them, ordered timing belt kit and aux belt and idler from them Wednesday and it's all here today most of it fiat branded...and a good postage price to Ireland.
Just waiting for casings now and water pump and will stick it all back together.
Marty.

My idler went tits up thought i would replace the idler along with the crank pulley (Geniune Fiat parts). Ever since i have had problems with the belt riding across the altinator pulley by one groove and noisy at revs and start up. I am on my third belt gonna hope i have bought a dodgy idler.

Try get to the bottom of it...most likely idler or tensioner wear/misaligned.
I feel I was lucky it didn't take out timing belt, it cut through the timing belt covers in 3 places and lots of plastic and rubber ended up in there....

Going to take a chance on a new idler, none of the aux belts snapped they just ate away one of the grooves on the belt as it jumped across on the altinator pulley, Frustrating it was new parts fitted and didn't play up before the original idler got noisy on tick over and had to be replaced.

Widemouthfrog. Thanks for your comment about the squealling after start. Mine did that for months and now it has got much worse. I was thinking along the lines of water pump (was going to post about it) but you described my symptoms exactly. What was the cure for you and how much were parts and was it easy? (sorry to divert this thread a bit )

The squeal after start is cos the alternator is initially working hard to replenish the battery which was just put under stress starting the car....and your belt is slipping.
You should just stick a new belt on it unless you have reason to suspect the tensioner or idler...
Marty.

squeal on start on mine was the fault of the crank pulley.

Interesting....was your crank pulley in a bad way... No longer staying concentric maybe until the engine got over a certain RPM or something??
Was their bits of rubber falling out of it?
Marty.

Multiplex - I had the aux belt and tensioner replaced on the recommendation of a local Alfa/Fiat specialist (non-franchised). He showed me that the belt was off-centred and pointed out the wonky tensioner. When we released tension on the belt, it was easy to see that the tensioner was u/s.
Cost to replace both was just over £90 inc. parts, labour and VAT. At that price, it's not worth replacing one without the other in my view.
Marty - you're spot-on about the reason for the squeal. The knackered tensioner means that the belt doesn't seat or track correctly, so it's less able to transmit drive to the alternator, so it slips. I guess a failing crank pulley could also result in the same behaviour for similar reasons.

Thanks for the advice. I'll have my head under the bonnet in the morning to check things out and then look at what needs to be ordered.Why does the weather get cold whenever the car needs looking at.....?