timing belt tensioner spring ?

SDI_Tim said:

It's the spring inside the tensioner, which pushes on the piston that pushes forward to tension the belt. With the cambelt off, you can remove the spring and measure it.

I changed the spring on mine, and found the new one over tensioned the belt - it whined when test driving. So I had to ignore the spring tension and do it by feel.

Most people don't bother with changing the spring, and after my problems after I did, I wouldn't bother again unless the spring is way different from the correct length.

You should be able to pick up a spring from an ex MG Rover dealer still doing the parts, or XPower dealer.

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SDI_Tim said:

From memory it's about 60-70mm long. If it's miles out from the figure in Haynes, say 5mm or more I would consider changing it. It is not a foolproof method of making sure the tension is right - if the belt feels very loose or whines when you drive the car, chances are the tension could be wrong.

As you said, hardly anyone mentions it. The cost was around £5, and the new spring over-tightened my belt when I relied on it to set the belt tension.

I would look carefully at the state of the two tensioner bearings (cambelt and fuel belt), and idler bearing. Iif these make any noise or feel rough when you turn them, or you can wiggle them about at all, then I would replace them for peace of mind.

I'm assuming you are changing the fuel belt at the same time. It makes sense. The auxiliary belt is worth changing for less than £10 also if at all cracked or old.

Apart from this, the most critical thing is having exactly the right sized locking bits, to get the timing right. Also make sure you apply enough torque to the crank pulley, (63Nm and then 90 degrees of rotation more I think), you might need a long breaker bar for this.

I think Haynes mentions replacing the crank pulley bolt, I wouldn't bother if it looks okay, and something about the cam pulley damper being removed and replaced with new, wouldn't bother with this either, and I don't think anyone else does either.

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CCM said:

i will have a think about it and buy a new one of there only £5

do i just as for a cambelt tentioner spring for a diesel 25 ?

ive got a full kit so everything is getting replaced i had a drive belt too but lost it so if i cant find it i will buy a new one and sell the other when i find it .

ive got the drill bits 6.75 and 9.5 but could not get a 6.75 so for a 17/64" is it ?

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SDI_Tim said:

Yes if you ask for cambelt tensioner spring this should get you the right part.

6.75mm or 17/64" are both fine.

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SDI_Tim said:

You'll soon find out. Measure it and see if it tallies with the Haynes spec?

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