300tdi squeak on idle - IDEAS?

[v8seriesone]

hello, got a small squealing kind of sound on idle on my 300tdi 90. when you up the revs it disappears. It sounds a bit like a belt squeal but i'm pretty sure its not as it's just had a new belt and the automatic tensionner seems to work ok. sounds a bit more metal to metal rather than belt noise anyway. anyone know what it might be?

[stageonesimmo]

The auto tensioner will work OK even if the bearings are squealing.  Its the usual suspect for such noises and its easy enough to tell if it is it - just spray the bearings with some lube or other and see if it quietens down, which I reckon it will.

Then you need to do the old penny trick on it and the squeak should be banished...........

[v8seriesone]

the old penny trick??  :?

[Les Henson]

Slacken the centre nut of the belt tensioner and put a 1p coin behind the assembly in the 9-o-clock position and re-tighten the nut. The tensioner is slightly out of line with the rest of the wheels and this causes them to squeal. If it still does it then the bearing needs replacing. You can't buy the bearing from L/R or even after market suppliers, but you can can get the same item from various bearing suppliers and replace it yourself, saving you at least £60.


Les.

[muck_truck]

after a new water pump, tensioner bearing and belt i still had the squeal.  (disco 300tdi)

Someone told me about the penny trick and it fixed it, but i had to put the penny (i used a washer cause im tight  :lol: ) at 10-11 o'clock ish.

then the power steering pump failed  :roll:

[v8seriesone]

i've put a bit of lube on all the pulleys, played with the tensionner, had a good listen and i'm now thinking its the water pump. main reason is when i slacken the tensionner with the engine running the squeal doesn't change and it should i think.

Dom.

[muck_truck]

i thought exactly the same as you. when engine is running put a ring spanner on the bolt that goes through the center of the tensoner wheel so its anywhere between 9 - 11 o'clock (not the bolt that holds it to the engine.) Then gently pull the spanner towards you so you are twisting the tensioner and see if the noise goes away. you may have to play about a little pulling a birt harder, pushing on it etc.

Give that a go. i had spent ages trying to fix this same problem and the washer fixed it in mins.

the noise comes from the groves on the belt climbing up the groves on the water pump pulley and then slipping back in cause the tensioner doesnt run true to the water pump pulley anymore. You may find the bolt that holds the tensioner to the engine is slightly bent as well.

Its cheap and quick to try before buying a water pump and new coolant.

[v8seriesone]

Thanks Dan I'll try that!

Dom.