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325 timing belt

Posted: Sun May 06, 2012 11:52 am
by jimmypee
I,ve seen the thread. I take it thats for a manual there are 2 pipes going into my rad are these cooling pipes for the auto trans oil. Do they just screw out. Also do most people take the bonnet off.

Re: 325 timing belt

Posted: Sun May 06, 2012 12:19 pm
by Topblag
Bonnet stays on. Airbox, radiator and viscous fan off.That gives you all the access you need. Just disconnect the auto box cooler pipes from the rad and put then in something to catch the oil drips.

The unscrew the nuts and pull them out of the radiator.

Re: 325 timing belt

Posted: Sun May 06, 2012 12:39 pm
by jimmypee
Nice one.

Posted: Sun May 06, 2012 8:20 pm
by jimmypee
Just reading the thread it's not clear whether you leave the tensioner loose so it tensions belt as it stretches or if you tighten it back up. Can anyone answer the question

Re:

Posted: Sun May 06, 2012 8:26 pm
by Rtaylor2208
Once you have removed the Old belt you need to push the tensioner hard up against the spring then lock it in position tightening the mounting nuts. Once that's done fit the belt, crank first then intermediate wheel, then cam and finally onto the tensioner.

Once that's done loosen the tensioner bolts to allow the spring to tighten the belt.

With the belt now tight, tighten up the bolts. Then reassemble everything.

Having just done this myself on a 325 auto on frIday I can confirm that it's a horrible job to do.

Re:

Posted: Sun May 06, 2012 9:39 pm
by Brianmoooore
Rtaylor2208 wrote:Once you have removed the Old belt you need to push the tensioner hard up against the spring then lock it in position tightening the mounting nuts. Once that's done fit the belt, crank first then intermediate wheel, then cam and finally onto the tensioner.

Once that's done loosen the tensioner bolts to allow the spring to tighten the belt.
Now turn the engine,by hand with a 22mm spanner on the crank bolt, two full turns in the forward direction, then slacken the tensioner bolts and allow the spring to tension the belt again while still applying a little pressure to the spanner, to ensure that the tension side of the belt is actually under tension. Tighten the tensioner bolts again.
Then reassemble everything.

Having just done this myself on a 325 auto on frIday I can confirm that it's a horrible job to do.

Re:

Posted: Sun May 06, 2012 10:02 pm
by jimmypee
did you replace the tensioner or just the belt. Mines had the belt done loads of times but not sure if the tensioners been done

Re:

Posted: Mon May 07, 2012 12:23 am
by Rtaylor2208
^^^^ Brian is the voice of expertise here. I rePlaced the tensioner also as it was literally £10 more than the belt, for at least 4 Years / 40000 miles of peace of mind it was worth it.

Re:

Posted: Mon May 07, 2012 7:24 am
by capri_rob
jimmypee wrote:did you replace the tensioner or just the belt. Mines had the belt done loads of times but not sure if the tensioners been done
ECP sell a timing belt and tensioner kit - not expensive and made by Contitech who manufacture the genuine belts for BMW.

For what they cost you may as well change the tensioner with each belt change.

Re:

Posted: Mon May 07, 2012 9:38 am
by Brianmoooore
Depends to a large degree on whether the belt is changed as a result of mileage or time.
On a garage queen that only does 1000 miles a year, the belt should be changed every four years, but there's little point in changing a bearing that's done just 4000 miles.
Note that there was a duff (M20) tensioner supplied at one time, marked Z139???, IIRC, and this should be changed on sight. The centre pin on these becomes loose, allowing the tensioner to run at an angle, and throwing the belt against the outer cover.

Re:

Posted: Mon May 07, 2012 12:06 pm
by jimmypee
Yeah it's only 45 quid for the continental belt with tensioner so will do both