Cambelt change update

Technical Area Engine, Transmission, Exhaust etc
2

 I have now completed a cambelt change on my Mk 2.5 Sport. The car is a 2002 model and has done 25,000 miles. The old belt is circa 9 years old therefore but was visually fine and had no signs of fatigue ie cracking or brittleness, etc. it looked like it was good to go for a lot more miles yet. I did notice however the new belt is a tighter fit and has less slackness in it than the old belt did at TDC before I released the tensioner spring. I also replaced the camshaft oil seals, belt idler and tensioner, crankshaft bolt, tensioner spring and cam cover gasket. I had bought and had intended to replace the crankshaft oil seal also but chickened out as everything was clean down there. Beware that the smaller of the two camshaft oil seals looks the same as the crankshaft oil seal but the latter is slightly larger. In the end I had no difficulty removing the oft troublesome crankshaft pulley bolt by putting the car in fourth gear, handbrake on and front wheels chocked and used a long breaker bar. I discarded the old bolt as a precaution due to the torque it is wound up to and purchased a new one from MX5 Parts. I found the 3 parts of the main pulley to be rusted together and never did manage to separate them …

In all it took me about a day over the period of a week - as the missus had me decorating for most of the time. Just go slow and careful and double check the timing once the new belt is fitted. Saved a few quid, which always engenders a warm feeling …

If anyone else is contemplating doing it themselves on the VVT engine and have any questions please contact me and I’ll try to help.

3

 Much respect to you. 

I have the same car, same age, with 18k miles.

The handbook says the belt does not need changing until 54000mls - no mention of age (which is unusual) - but I’m starting to get nervous about it and will have to bite the bullet soon.  I’m not noted for my mechanical ability though!

4

 Hi Bob

Knowing what I know now, I probably wouldn’t have changed my belt this time around and I’d have left it for another two or three years. I would guess the oil seals will fatigue before the cambelt does and therefore you may see drips of oil under the car first. If you do decide to replace the belt yourself it does help you get to know your car and you get a great feeling of satisfaction on (successful) completion. You do need the following though - time, a good set of tools, a decent working environment , and a source of technical reference that will give you the sequence of removal, torque settings for bolt re-tightening, etc. I bought Rod’s workshop manual for the Mk 1 1.8 which helped but Wayne, a frequent contributor to these forums, also helped me out too (and many thanks to him). I do have some photos I took when setting the timing which is the only tricky bit I encountered but you just have to be careful and check and re-check before re-assembly.

Regards

5

Thanks for the advice - much appreciated.

I certainly understand what you are saying about the feeling of satisfaction upon completion, but with my luck I would have some bits left over!  Will have to give it some thought.

Regards

Bob C