CDTi auxillary belt tensioner issue

[LeRich]

Hi guys.

The car failed on me last night after a few days of electrical issues. I suspected the alternator being at fault due to the nature of the warning lights and a recent new battery. The recovery guy did all sort of tests and concluded that the alternator was OK but not kicking out the current it should, most likely because of a slipping belt.

There had been no screeching of the belt prior to indicate this but having looked at it today, while the belt is tight, it is not quite tight enough.

So having been out to buy the required 24mm spanner I set about investigating the tensioner. Having read numerous related threads, most people find the bolt stiff to turn as they fight against the tension. Not mine however. When turned clockwise as if to tighten, it required relatively little force to turn. I then tried anti-clockwise as if to loosen the tension and again it took relatively little effort.

The tensioner pulley wheel is now skewed and not sitting in line with the belt and other pulleys. I can see the nut into which this bolt passes and there is a section of exposed thread suggesting the bolt is rather loose. The nut is not captive as turning the bolt turns the nut.

Has anyone encounted this issue? Is the tensioner knackered or will tightening the nut/bolt (assuming I can even reach the bolt) sort it out? Any ideas welcome.

[Mike Noc]

Get a spanner on the back nut, a bit of loctite behind the bearing and tighten it as much as you can. It is a left hand thread.

[LeRich]

Get a spanner on the back nut, a bit of loctite behind the bearing and tighten it as much as you can. It is a left hand thread.
Cheers. That was my thinking too. I'll have to remove the PS pump to get to it first though which is a bit daunting.

[Mike Noc]

Go in from underneath and all you have to remove is the undertray. :D

[LeRich]

Go in from underneath and all you have to remove is the undertray. :D

The bolt is too obscured to get to from underneath. It's visible from above, but can't be reached because of the PS pump.

[LeRich]

Bit of an update:

I've been able to tighten the tensioner pulley bolt up. Removing both aux belts improved access to the tensioner and allowed me to get a 16mm spanner to the nut behind. Slowly tightening the nut and bolt (turning the 24mm spanner anti-clockwise instead of the usual clockwise), the tensioner straightened up and returned to the correct position. Once tightened, applying further pressure to the 24mm spanner rotated the entire tensioner against the spring loading as it should do so I'm confident at this stage that it's ok.

All I need now is to fit a new belt set and check it all works smoothly.

[Mike Noc]

Good work - sounds like you are sorted. :D

[DMGRS]

Excellent news, hopefully that's the issue sorted for good. Congratulations on fixing it for free, too! :D

[LeRich]

Congratulations on fixing it for free, too! :D

Cheers, but not quite! The air con belt has had it and I had to cut the aux belt to get it off so have just ordered a fresh pair - from yourself as it happens!

I suspect both belts are original as the AC belt looked ancient and there's no mention in the service history of their replacement.

Hopefully once the new belts are on and everything back together the alternator will be fully functioning and I can get my car back on the road.

[DMGRS]

Fingers crossed that sorts the issues out for you - if so, happy days. The A/C belt is often ignored.