How to replace the timing belt tensioner...

The timing belt tensioner is a common problem on the 1.2 8v engines in both the MK1 punto and the MK2. Signs of a failing tensioner is a grinding, whirring, squeaking or screeching (in very bad cases) noise coming from under the plastic cover on the drivers side of the engine. Sometimes the noise is constant, sometimes within only a particular rev range.

This guide is based on a MK2, but the MK1 is a similar proceedure, only the mounting point being slightly different. Its usually recommended to change the timing belt at the same time, but in some cases this isn't required - here I only replace the tensioner due to the belt being quite new anyway as can be seen by its moist rubbery look - if yours looks dry, its probably best to replace the belt aswell. If you don't feel like taking up that challenge, you should be OK anyway as this engine is non-interference and so in most cases, no damage is caused should the belt snap.

Time taken: Less than an hour.

So this is the car before any work commences....


And here the new tensioner....


Remove the air intake pipe by squeezing on the top and bottom of the hose and pulling....


Support the engine with a jack, placing a piece of wood between the jack and the sump to prevent damage to the sump. Jack it up slowly until the car starts to raise slightly then stop immediatly. Now you are taking the weight of the engine on the jack....


Undo the 4 13mm engine mount nuts equally half a turn at a time so as to not put strain on just one nut as you finish....


Then the 3 17mm lock nuts holding the mount to the chassis...


Move the mount out of the way...


Then remove the second half of the mount with the 4 15mm bolts holding it to the engine...


Pull the mount out of the way (you can just see the tensioner here now)...


Pull the connection block out of the plastic cover and pull the wiring out of the cover all the way around...


Remove the 3 10mm bolts holding the cover in place...



Pull the top half of the cover away and the tensioner and camshaft pulley are now clearly exposed...


Remove the final 10mm bolt to remove the bottom cover...


Now the crankshaft pulley is exposed...


It always helps to have an assistant


Use tippex to create timing marks on both the crankshaft and camshaft with the belt - I couldn't find any tippex so nailvarnish had to suffice It can be hard to get a timing mark on the crankshaft but can be done if you have small hands. If not, the alternator must be loosened and the drive wheel for it also removed. It is important to get these marks as one slip of the belt while its slack, or a slight movement of either shaft will mess up your timing.


Now remove the tensioner with the 13mm nut. As its removed, tension the belt with your finger to help prevent the belt moving...


Keep hold of the little metal disc that holds the tensioner in place, and swap the tensioners (still holding tension in the belt with your finger.) In this photo, you can clearly see the condition of the old tensioner next to the newly installed tensioner. Force the tensioner forward to tension the belt fully and tighten the nut tight! To gauge the correct tension without the correct tool, you want it tight enough so that along the longest stretch of the belt, you cant quite twist it a quarter of a turn...


Then reassemble in reverse order. Its worth mentioning when tightening the 4 13mm mount nuts, to do them half a turn at a time in a cross shpe - i.e. top right, bottom left, top left, bottom right and repeat until there all tight. Once there tight, remove the jack before tightening the 17mm locknuts from the mount to the chassis - this way the mount will settle in its natural positon. Then tighten the 17mm locknuts.

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