Whiney m20 after cambelt change

Post Wed Sep 07, 2005 6:26 pm

Basically, I changed my cambelt (& tensioner, PAS & Fan belts), & when I removed the original, I found no tensioner spring! Decided that it wasn't really essential, so just tensioned it by hand, to about what I thought it should be (& what it was before). When I put it together, it seemed a bit whiney. **** thought I; must have done it too tight.

So off I went to the breakers, got myself a tensioner spring (GSF don't do em apparently), fitted & re-tensioned it. Then I put it back together, it seemed to be a remarkably similar tension, & yup, it still whined! Must have just not noticed the noise before, I thought.

So I drove it last week, (on a classic car rally - lots of good pics btw!) & did about 1000 miles with no probs.

It's still playing on my mind though! Was the noise there before? Is it normal? Is it something other than the cambelt? Is my cambelt about to snap?!

Any thoughts on the matter anyone???

Post Wed Sep 07, 2005 6:34 pm

could be your power steering or fan belt

Post Wed Sep 07, 2005 10:28 pm

Quaser wrote:could be your power steering or fan belt

Could be, but I changed them after I did the cambelt & it did it both before & after...

Post Wed Sep 07, 2005 11:28 pm

It's not normal for the belt to whine.
Take the two V belts off and run the engine for several seconds to eliminate them.
Vaguely reember that there are two different belts for the M20 - one for squ
are edged teeth, and one for rounded, but I may be thinking of a different engine.
Don't assume that new idler = good idler.

Post Wed Sep 07, 2005 11:36 pm

Check the belt pully's for wear.
They may not be a smooth v shape anymore and can grip the belts too much.

Does the timing belt sit in the same place as the old one? it could just need to bed in and wear away the rust thats formed on the sprockets. (but thats your call, if you leave it and thats not the problem it could be too late before you work out the cause)

Could be the fan belt is tighter than the old one (normal tension) and is showing the wear in the water pump bearings. It's worth replacing the water pump when you do the timing belt as it's only about Ãƒ”šÃ‚£20 for a new pump.

Post Fri Oct 28, 2005 11:15 am

Hokay, well I don't think it's going to go away by itself...

I've tried running without each belt & there's no change... I guess it must be the new belt or tensioner then

Anyone got any more ideas before I go through it all again? Methinks it'll be on BMW parts rather than GSF this time

Post Fri Oct 28, 2005 12:07 pm

When i did mine i cocked the covers up, i put the bottom one on first and then the top one, which pulled the bottom one too close to the tensioner and the cover rubbed on it, or was it the other way round? Anyway just check the cambelt covers.

Post Fri Oct 28, 2005 3:29 pm

How was the belt tensioned??

Did you rely on the spring or did you add a bit to be sure??

Post Tue Nov 01, 2005 1:31 pm

Andy_magic wrote:How was the belt tensioned??

Did you rely on the spring or did you add a bit to be sure??

First time there was no spring (

), so I did it by hand to the same tension it was at before & it was noisy so I stopped it straight away, went out & got a spring. Did it again using just the spring tension, it seemed remarkably similar, but what can you do?! Put it back together & it was still whiney