How on earth does one remove the locking pin from a new drive belt tensioner once installed? For starters its very hard to access. I just about managed to grip the end of the pin with some water pump pliers, but the spring is holding it in with so much force that I have no chance of pulling it out from this awkward angle. Am I meant to use a long handled spanner to push back the tensioner slightly (to release load on the pin?). In which case wouldn't it be easier just to remove the pin before installing and use that spanner to re-fit the belt?

Which engine does the car have in?

When I've done them on 1.9's, I've had to use a really long spanner to get the leverage to wind the tensioner off, doable, just needs the force/ As far taking the pin out, I think I've normally just used a pair of grips or heavy pliers and just wiggled and pulled

It's the 1.9 VRS. Did you need the long handled spanner to relieve load on the pin when pulling it out? And as for using pliers how did you manage to get access without removing all the intercooler pipework first?

By way of an update, the pin came out with gentle pulling using fingers when I used a long handled spanner to jiggle the tension on the pulley. Lucky, because there was no way I was getting pliers down there and be able to put meaningful force on them. The new pulley seems not to have the problem of the old one of thr belt not being properly centred on it, which touch wood will allow the belt to have a proper lifetime before it breaks.

On 02/01/2026 at 18:50, tham383 said:

By way of an update, the pin came out with gentle pulling using fingers when I used a long handled spanner to jiggle the tension on the pulley. Lucky, because there was no way I was getting pliers down there and be able to put meaningful force on them. The new pulley seems not to have the problem of the old one of thr belt not being properly centred on it, which touch wood will allow the belt to have a proper lifetime before it breaks.

Just to add, check your alternator clutch. When mine jammed solid it wore out the tensioner.

On 06/01/2026 at 21:26, Tailhappy said:

Just to add, check your alternator clutch. When mine jammed solid it wore out the tensioner.

Forgot to mention this.. The clutch is quite stiff. If I jam the fan blades with a screwdriver, the pulley is easily turnable (in one direction only) with fingers but it certainly won't free wheel under its own momentum like it does with the clutch disengaged. But this alternator including the clutch is new. I still have the old one which seems to be a bit stiffer, but the difference isn't dramatic. Should the pulley be able to free wheel when the clutch is engaged?

8 hours ago, tham383 said:

Forgot to mention this.. The clutch is quite stiff. If I jam the fan blades with a screwdriver, the pulley is easily turnable (in one direction only) with fingers but it certainly won't free wheel under its own momentum like it does with the clutch disengaged. But this alternator including the clutch is new. I still have the old one which seems to be a bit stiffer, but the difference isn't dramatic. Should the pulley be able to free wheel when the clutch is engaged?

I'm not quite sure what you mean by the clutch but the alternator should (when the engine is turned off from idle) spin down over several seconds and start instantly when the engine starts again. The freewheel bites 100% in one direction and is easy to turn (with alternator internally stalled) by fingers the other.

On 16/01/2026 at 09:14, Tailhappy said:

I'm not quite sure what you mean by the clutch but the alternator should (when the engine is turned off from idle) spin down over several seconds and start instantly when the engine starts again. The freewheel bites 100% in one direction and is easy to turn (with alternator internally stalled) by fingers the other.

Might be clearer as follows:

With the fan blades blocked (e.g. using a screwdriver through one of the air vents):

A. - Clockwise - pulley can't rotate

B. - Anticlockwise - pulley can be turned easily with fingers, but won't continue to spin under its own momentum (too much friction)

C. - With the fan blades allowed to rotate freely: You can turn the pulley easily (in either direction) with fingers and it will continue to spin under its own momentum.

I'm worried about scenario B .. Should the pulley spin easily under its own momentum in this case?

Edited 20 January20 Jan by tham383

On 20/01/2026 at 14:56, tham383 said:

Might be clearer as follows:

With the fan blades blocked (e.g. using a screwdriver through one of the air vents):

A. - Clockwise - pulley can't rotate

B. - Anticlockwise - pulley can be turned easily with fingers, but won't continue to spin under its own momentum (too much friction)

C. - With the fan blades allowed to rotate freely: You can turn the pulley easily (in either direction) with fingers and it will continue to spin under its own momentum.

I'm worried about scenario B .. Should the pulley spin easily under its own momentum in this case?

That does sound like its working as it should. The clutch does have some friction as it has to be ready to engage instantly and supply a substantial amount of force (especially when glow plugs are on).

However this pulley is a known failure point which when it does fail really stresses the entire auxiliary belt system. So if you were to replace it (not a difficult job but need an impact drill and the special tool) you will be more confident that your system is not likely to fail between auxiliary belt replacement intervals.

Reassuring...

The pulley is newish, since it came and with new alternator at a point last year. So hopefully it will be ok.