Disco Tdi 96 serpentine belt noise again.

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Originally Posted by Cresta

Hi ralph,
It would seem that the tensioner pulley somehow gets out of line with the serpentine belt. So by placing a small coin ( 1 pence in England ) in the 9 '0' clock position provides just enough correction to pull it all back in line.
With regard to any worries about excess strain on the tensioner bolt, don't worry, i have never heard of a failure relating to the above fix. providing you torque it to the correct value.
As an aside i would guess maybe 75% of British Discovery owners have used this fix. My own 300tdi has covered a grand total of around 400,000k's and purrs like a kitten and it never squeals !
Hope this is of help to you.
Thanks
Geoff

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Thanks Geoff. I've spent a couple of hours today tracking down a main belt chirp/squeak in my 300tdi D1 and that was what finally fixed it.
I noticed that the squeak only happened at idle when the tensioner was jumping around. As soon as it was lifted above idle rpm the noise disappeared and the tensioner became steady.
I initially thought that it was in the tensioner itself, but liberal doses of dri-lube spray in the front of the tensioner didn't make any difference. It was only when I gave the back of the belt a quick spray that the noise stopped, but came back a minute or so later.
From that I knew that it wasn't related to the ribbed side of the belt, and I tried putting a flat washer about 1.5mm thick at the 9 o'clock position behind the tensioner - Instant silence!!

I also noticed that after the fix the tensioner no longer jumped at idle, and that the tensioner pulley was rocking smoothly from side to side slightly as it ran. Previously (when squeaky) the pulley was rock solid and only the tensioner jumped - presumably as the pulley had a side load.

Steve

Quote:

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Originally Posted by Cresta

Hi ralph,
It would seem that the tensioner pulley somehow gets out of line with the serpentine belt. So by placing a small coin ( 1 pence in England ) in the 9 '0' clock position provides just enough correction to pull it all back in line.
[SNIP]
Geoff

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I suppose with the UK financial downturn a 1 pence piece would cheaper than using a washer. :p

For those of us who don't have access to UK currency, could you give us a rough idea of the thickness?

Although I suppose the optimal thickness for each situation would depend on the amount of wear on the tensioner.

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Originally Posted by vnx205

I suppose with the UK financial downturn a 1 pence piece would cheaper than using a washer. :p

For those of us who don't have access to UK currency, could you give us a rough idea of the thickness?

Although I suppose the optimal thickness for each situation would depend on the amount of wear on the tensioner.

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SteveG has already answered your question in this thread.
A flat washer of 1.5mm was what he used.
As you quite rightly say, in the UK a washer would be too expensive to buy, thats why we use coins

i have just had the same prob in my 300tdi. in the end it was the tension pulley. if your tension pulley is jumping any more than 5mm its time to change her over. in my case, my tension pulley was jumping around that much, my belt came off the pulley and ened up on the edge of it, shredding it apart. put a new belt on her and i had the noise coming from the pulley it self. change it over and no probs. :)

There are 2 belt lengths, the later one which would be for your 96 is 15 mm shorter. Ifr you have had the early longer belt fitted this makes the tensioner jump up & down and can cause squealing. The alternator pulley was a smaller diameter on the later 300 tdi this is why they have the shorter belt.
if you have not resolved this yet email my tomorrow and i will check the belt lengths.

Alan howard

In a last ditch attempt before replacing the tensioner as I had the ever annoying chirping (tried new belts, talc worked for a while until wet, probably more vertical movement than there should be but not more than 5mm I'd guess) I used the coin between tensioner and block and it hasn't made a sound since.

Worth a shot before spending money. It only cost me 5c ;)

Seano

make sure you check the tensioner.....thought all was good with mine but lept getting the chirp only difference with me was I had 2 belts over a period of time get chewed slightly on the edge.....

happened to look at the tensioner at a funny angle only to find the nylon bush in the tensioner had colapsed and the tensioner had actually kicked it slef out slightly towards the belts making the belts touch on the edge of the pulleys

new tensioner and all was good.......

also listen to your bearings in your airconditioning pump they too can be a little missleading when it comes to chirps and rattles

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Originally Posted by Cresta

Hi to all in Aus, :)
The noisy belt problem is very common in England (maybe the damp weather)
Our tried and trusted solution is to loosen the tensioner from the engine slightly and place a small coin in the 9 '0' clock position and re tighten the tensioner and jobs a good un. no more nasty noises.
Regards
Geoff

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Have just done this and it works a treat.

I took the tensioner off and super glued a 10 cent piece to the engine.

Belt now quiet as a mouse.

Dave.

This worked for me

Remove the belt- Back off the tensioner mounting nut- slip a 1.5mm washer between the tensioner and the aux mounting at 9 oçlock position (facing it from front of engine)- re tighten the nut- install the belt.

This compensates for the offset that develops in the rubber bush inside the tensioner

The squeal has gone.

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Originally Posted by seano87

In a last ditch attempt before replacing the tensioner as I had the ever annoying chirping (tried new belts, talc worked for a while until wet, probably more vertical movement than there should be but not more than 5mm I'd guess) I used the coin between tensioner and block and it hasn't made a sound since.

Worth a shot before spending money. It only cost me 5c ;)

Seano

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I too had a noisy belt, brand new - the old one made a bit of noise in the morning but nothing like the new one. The 5 cent coin at 9 o'clock (held in with some double sided tape until tightened) worked perfectly, no more squeals. Thanks to all for this solution.