XUD Td crank pulley symptoms

[John Plum]

Hi all,
I'm beginning to suspect the crank pulley is the cause of alternator drive gear squeaking at idle, which vanishes above 1100 revs.
Other symptoms include a twisting and thrashing aux drive belt on the run between AC and crank pulley.

Would a defective crank pulley cause very noticeable uneven engine vibration when sitting in the cabin, at idle speed?


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[Peter.N.]

If you look at the pulley with the engine running you should be able to see it running out of line if its failing. Shine a light on it.

Peter

[Xaccers]

Get a marker and draw a line across the rubber ring on the face of the pulley. If after some miles the line is broken, it means the pulley is failing and the outer is slipping around.

Your symptoms of a flappy belt suggest the auto tensioner isn't able to hold the tension on the belt, which could be down to the eccentric tensioner needing adjusting, and the eccentric may need replacing. Spray it with silicone or even WD40 and see if it stops squeaking.

[citroenxm]

What xac said!.. xud crank pullys are a lot stronger then hdi ones. Ive rarely seen one play up.

Id be more inclined to blame the aux spring tensioner too.. with the engine running look down from the top between the engine and chassis and watch the tensioer. You should see it bouncing. Lift the revs on the pump and it should smooth out.

[Xaccers]

Good point Paul, the roller part of the auto tensioner often gets replaced with it's spring being ignored.
On Cassy the lower eye of the spring had destroyed itself and was gradually wearing away the bolt that holds it in place.

I've currently got a problem with Cassy where her eccentric needs replacing, but the 8mm hex bolt has rounded, so I'm hoping I can whack in a torx and use that to unscrew it. The belt's getting quite flappy so it really needs to be done.

[citroenxm]

Had that ALSO Xac, the eccentric 8mm bolt appears to tighten itself up!! They dont need a lot of tightening.

I had one, but I didnt use a Torx, I used a SPLINED Bit, which had more "Ridges" on it to grip to the internal rounded edge..

The End of the spring mounts go Elongated from constant wacking from the bouncing roller, and its a soft metal too..

For example, one of these: http://www.ebay.co.uk/itm/LASER-0592-SP ... 2a395ecc6a" onclick="window.open(this.href);return false;

Worked a treat once SMACKED into it!

[John Plum]

This is all good stuff to me fellas, helps me a lot. I replaced the tensioner and spring 10 000 miles back, but may have problems with spring eye. I'll look it over.
A long belt I suspect, might be a problem I have, and a squeaking eccentric. My eccentric is fully rotated to 180 degrees.


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[John Plum]

Looking again, I see no bounce in the auto tensioner.
I'm going for the eccentric and shorter belt... First.


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