Cambelt

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paultv
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Post Sat Feb 10, 2018 8:46 am

OK so I changed my cambelt, waterpump and camshaft front seal 18 months ago.

The car has driven about 7000 miles since.

The Febi water pump started making a horrible racket when the engine was hot, so I decided to replace it, just can't stand the noise any more, especially at idle.

Opened everything up yesterday, -3c in the garage! and I'm a bit concerned about the cambelt. It was a new Conti Continental kit with correct number stamped on the tensioner pulley, but now the back surface of the belt is covered in tiny cracks.

Is this normal wear for the mileage or should I replace it for a "better" make?

Suggestions?

Its pretty crap to have the Febi pump bearings fail after a week, but the belt also?

Are these just crummy parts I wonder, I'm sure the old belt was worn, but just shiny.

Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

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martauto
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Post Sat Feb 10, 2018 1:57 pm

Both should do better than 7000 miles but both to start to go seems very strange.

Mart.
Only the E46 cab left now.
Just got too old.
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arrisbmw
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Post Sat Feb 10, 2018 10:09 pm

change the belt too. if the pulley of the water pump was getting hot due to the failing bearing , that would probably cause the belt back to have cracks in it.
when you fitted the new belt , did you also change the idler and adjuster pulleys too.
how did you tension the belt ?
I understood conti belts were good. the cambelt should last 35 k , depending on driving style.
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paultv
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Post Sun Feb 11, 2018 2:17 pm

Everything was new, and the tension was set using the pin and spring in the usual way.
I've picked up a Saleri water pump, appears much better engineered than the Febi which looks cheaply cast.

Replacing the belt makes sense whilst I'm in there.

Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

https://bmwe30cabriolet-wdm.blogspot.com/
clipper
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Post Mon Feb 12, 2018 3:48 pm

Shouldn't be anything wrong with a Conti belt. I was recommended Conti years ago and I just replaced my first one last year, after 6 years running and 3 years standing. Honestly, it didn't have any signs of wear / fatigue.
These are sensations as hard to forget as they are to ignore.....
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paultv
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Post Wed Feb 14, 2018 7:02 am

So everything's out. The old cam belt has a worn outer edge - although it was centered on the tension idler and the cam gear, there is evidence of wear to the inside of the lower belt cover piece as well, indicating that the belt could have crept towards the outer edge when running - is this possible? does the belt simply stay put once under tension assuming all the bearings involved are good?

Also, the old tension bearing is noisy - so maybe this is the root cause of everything - as you turn it, it's crunchy but not much play.

Anyhoo - all the new stuff going in today, with a careful eye on alignment.

Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

https://bmwe30cabriolet-wdm.blogspot.com/
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Brianmoooore
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Post Wed Feb 14, 2018 10:11 am

There's a common fault where the centre pin of the tensioner bearing works loose where its riveted to the rest of the tensioner bracket. This will throw the belt outwards, against the cover.
There was a recall on one particular tensioner (Z31??), but I've seen the problem on other versions as well.
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paultv
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Post Wed Feb 14, 2018 12:15 pm

Hi Brian,

Yup, I read about people welding the rear of the pin to secure it permanently - I think I just had a really unlucky collection of new parts - the new Saleri water pump is silent, and the car is driving perfectly after it's first outing in the snow this morning.

I hope the new belt and tensioner last a bit longer this time round - it's another Conti.

Paul :-)
4th May 1990 325i Convertible.

BMW E30 Cabriolet Best Mod Ever:

https://bmwe30cabriolet-wdm.blogspot.com/