Want to sort out the notorious 300 tdi belt squeal!!

[sjl81]

Hi all, after viewing my new disco prior to purchase at a dealers, I asked for the squealing noise to be sorted. They said yes no problem will replace the tensioner bearing.

On collecting the truck the dealer showed me a well worn bearing saying this is what they found, took it out replaced with new but is still making the noise and not to worry its a 300 tdi trait and not terminal. I read up about it and happy that it was nothing major.

A couple of hundred K's down the line and there is now also an annoying rattling noise coming from the same place. On running the car for 30 seconds without the drive belt, both noises are non existent.

I have had the pulley off had a look as was suspicious they didnt replace bearing, but in fact it does look like its new and been replaced.

There is a fair amount of play in the bearing though, and the amount of play varys depending on the rotational positional of the pulley, ie if you turn it 90 degrees theres alot more play than there was in the previous position. There is certainly more play in this pulley when comparing it to the crankshaft pulley which has a tiny amount of back and forth movement. (i've read a small amount of play is fine) The pulley does spin smoothly though, seems

So what does this mean, has this new bearing given up the ghost, and if so why has it given up so quickly, do i need to do the penny coin behind the tensioner mod and then should I replace the bearing with another new one?

Whats the best course of action?

[B92 8NW]

Replacing the bearing in the tensioner is a plebeian band aid solution. You need to replace the whole tensioner. It isn't outrageously expensive and mine has been good for 80,000km since.

[rangieman]

The penny fix as it is called in the uk it worked on mine and a few mates Tdi,s that i mentioned it to , You can gooogle Tdi belt squeal as i did and solve it , I just used a 5c coin behind the tension;)

[sjl81]

Replacing the bearing in the tensioner is a plebeian band aid solution. You need to replace the whole tensioner. It isn't outrageously expensive and mine has been good for 80,000km since.

My understanding from reading about this issue is its an alignment issue thats why the coin behind the tensioner helps. How does a new tensioner rectify this issue, if indeed it is the misalignment that is the problem. Are new tensioners engineered differently?

[sjl81]

The penny fix as it is called in the uk it worked on mine and a few mates Tdi,s that i mentioned it to , You can gooogle Tdi belt squeal as i did and solve it , I just used a 5c coin behind the tension;)

Just so happens i have a spare penny coin (moved over from uk 9 months ago ;)) what is superior lol a penny or 5 cent piece, the penny would work out cheaper :D

[B92 8NW]

My understanding from reading about this issue is its an alignment issue thats why the coin behind the tensioner helps. How does a new tensioner rectify this issue, if indeed it is the misalignment that is the problem. Are new tensioners engineered differently?

The issue with alignment is on account of wear between the two sprung halves of the tensioner assembly.

[dirtfisher]

Hi mate, I would also be checking the state of the power steering pump. There is a well known problem with the pump pulley moving in & out on the shaft. This can also be a cause of belt squeal & belt fray.

[sjl81]

how critical is the torque value when retightening the tensioner pulley? my torque wrench doesn't torque on left hand thread :wacko:

i've bought a new pulley bearing as it was only 7 bucks, put it in the pulley and trying to put it back on. have tightened it up a fair bit but can you overtighten?

theres still play in this new bearing although at least it feels an even wobble all around now! i'm guessing this must be normal for this type of bearing.

going to try the coin trick as a temporary measure, till i get more funds to replace the tensioner.

[sjl81]

...

[sjl81]

Replacing the bearing in the tensioner is a plebeian band aid solution. You need to replace the whole tensioner. It isn't outrageously expensive and mine has been good for 80,000km since.

Hi, what did you replace with, was it genuine or aftermarket? Cheers

[theborderdog]

Definatly replace the whole tentioner, just solved the problem on mine. Same symptoms you describe.

[dullbird]

as said with the power steering I would take off the belt and check all pulleys......

the other thing I had also found after changing a few of my pulleys which needed changing due to wear.....a little while after my belt began to squeak again especially on start up..and what we found was the serpentine belt I was using although it was a good quality belt had a shinney back to it we changed it for a dayco belt which has a rough back and no more squeaks ever again..the tensioner was having issues gripping the belt which was making it chirp

[rangieman]

How did you go with the coin trick , Mine has been quiet for 2 years and about 60,000 ks :D

[vnx205]

Surely the coin trick only works if the tensioner is misaligned.

If the tensioner puller was running true, wouldn't the coin just create the same sort of misalignment (in the opposite direction) as a worn tensioner pivot, thereby creating a squeak rather than eliminating it.

[SimonM]

I tried the coin trick yesterday and it certainly quietened mine a lot though I need to check the power steering pulleys to be safe. On a long drive yesterday the sound was not evident at all, prior to this it sounded atrocious.

[rangieman]

Surely the coin trick only works if the tensioner is misaligned.

If the tensioner puller was running true, wouldn't the coin just create the same sort of misalignment (in the opposite direction) as a worn tensioner pivot, thereby creating a squeak rather than eliminating it.
Of course what happens when the tensioner is worn and the rubber with in it has compressed:cool: it only prolongs what will eventually be a total replacement of the tensioner:angel: , But as i say mine has been quiet for 2 years with the coin trick , So for me it has been more than a tempory fix ;)

[waltsd]

Sure its not just the serentine belt. Mine was driving me nuts with the noise. The belt looked ok and was only 2yrs old. Replaced with new - now peace and quiet. It sounds like a new car again! It probably was doing it for a while?

[sjl81]

well i did the coin trick yesterday and put in new bearing it was completely silent for about 2 minutes then the chirp started again, but absolutely no where near as bad as it was before. whether this was due to the new bearing or the coin who knows?

The drive belt is new, fitted march this year and done at landrover, so presumably a genuine part.

the power steering pump was replaced 2 years/23000k ago so hpefulley this is still good and on checking the pulley seemed fine to me.

[dirtfisher]

Also be aware that there is two different belt lengths for 300 tdi's. The early models used a 1595mm long belt. Later models used a 1580mm long belt. You can do a search & it will tell you by VIN when the change occurred.

[sandman]

i did the coin, followed by a nwe tensioner, now i have power steering pump issues. it's been a blast!
has anyone tried just moving the pulley back to alignment? i'll be replacing it shortly anyway...

[steve_a]

I popped a washer behind the tensioner while putting the water block back together, I put the old belt back on and confirmed that the noise wasn't there. Now it may have been the water pump (leaking from drip hole, rubber inside had gone, but bearing still felt good).
New belt on as well and it's just happy diesel noise now.
Before I did this work though, I happened across this Dayco - Belt Noise Tech Tips - YouTube from dayco and tried what they said. Seemed to indicate chirp when I did, until it all got very wet and then I got squeal :)
I also noted that the tensioner was shiny but for a run about 2mm wide on the inner edge, this is an area that will now be being run on with the washer in there.

[gazby]

Lots of discussion here about the serpentine (alternator, water pump, P/S) belt maybe look elsewhere, I have had this same problem "belt squeak" with my previous '97 Disco Tdi and now my next Disco, a '98 Tdi.
The squeal in the '97 was due to a timing belt idler (Bend) pulley, the one that runs on the back of the timing belt opposite the tensioner pulley, I replaced it with a new one when I replaced the T-belt, noise gone !
The '98 had the same sort of noise when I picked it up from the previous owner, and I thought it was the same source, but after a few plays with starting the engine cold/hot, loading up the electrical system etc, I found that the noise was coming from the A/C compressor drive belt tensioner, the noise will always show up because whenever the engine is running that belt is driving the "free" member of the clutch mechanism, the noise came in at different revs depending on if the A/C was on or off, this is a far easier fix than the T-belt one and and worth a look.

[dullbird]

Lots of discussion here about the serpentine (alternator, water pump, P/S) belt maybe look elsewhere, I have had this same problem "belt squeak" with my previous '97 Disco Tdi and now my next Disco, a '98 Tdi.

The squeal in the '97 was due to a timing belt idler (Bend) pulley, the one that runs on the back of the timing belt opposite the tensioner pulley, I replaced it with a new one when I replaced the T-belt, noise gone !
The '98 had the same sort of noise when I picked it up from the previous owner, and I thought it was the same source, but after a few plays with starting the engine cold/hot, loading up the electrical system etc, I found that the noise was coming from the A/C compressor drive belt tensioner, the noise will always show up because whenever the engine is running that belt is driving the "free" member of the clutch mechanism, the noise came in at different revs depending on if the A/C was on or off, this is a far easier fix than the T-belt one and and worth a look.

I had this changed on mine at one point too I'm glad I did simply because when they went in to the timing case they noted that the modification to the time case was never done....

[Chookie]

Ahh.. The serenity!! One washer, One 15mm Socket and 5 minutes - wish I'd read about this 3 belts ago..

Cheers,
Chookie
'98 (quieter) 300Tdi Disco

[Spagga]

The penny fix as it is called in the uk it worked on mine and a few mates Tdi,s that i mentioned it to , You can gooogle Tdi belt squeal as i did and solve it , I just used a 5c coin behind the tension;)

That's what I did as well. 5c is a cheap fix!!