Cam belt change on an M20

[Brianmoooore]

There's no need to slacken the belt off. Just fit the pump without the spring, and refit the spring at the next cambelt change.
If you're going to use sealant as well as the gasket, use it very sparingly, especially if it's the silicon rubber type. That stuff can be a menace, as it squeezes out of the joint inside, hardens and breaks off. I've seen more than one oil pick up filter in a sump badly clogged by this stuff on engines where its been used on the sump gasket.

[clarko74]

I'm just about to change my timing belt/waterpump. Are the gaskets that come with non-bmw pumps (I've got the best quality pump that GSF do) not very good then? Should I wait and myself get a BMW one? Considering it's quite an effort to get to it I'd rather get it right the first time.

[clarko74]

For anyone wondering the what the difference between the pre and post-facelift pumps is here are a couple of photos (yes I did get the wrong one the first time! but it was due to ECP's dubious website giving incorrect information):

Pre-Facelift:


Facelift:


I've also put this info on the Wiki: http://www.e30zone.net/e30zonewiki/inde ... ater_Pumps

[Brianmoooore]

They might well not be as good, but the pump gasket is not a weak point in any way on these engines, as long as its fitted correctly.

[clarko74]

I'll stick with the one I have and give it a go then, cheer's Brian.

[kman82]

If I was starting from scratch I'd definately get a BMW gasket as it looks and feels much better than the kwp one I got, like brian said though I guess it's how you fit it!

[murran]

the gaskets with non gen pumps are like paper. fit these with hylomar blue sealent or you'll find your car having a wee while your filling it up.

[Simon13]

rubbish! i've never had a leak from the gasket when fitting a genuine or non genuine gasket/pump.

[Brianmoooore]

Gaskets are only needed anywhere to take up imperfections in the two surfaces being joined. If the surfaces fit together perfectly, then in theory, no gasket would be required anywhere.
The thin gaskets will be perfectly adequate if both mating surfaces are good, but I suppose if either surface is pitted or not as flat as it should be, then the thicker gasket will seal where a thinner one might not.

[murran]

i have had it a couple of times, now i dont take the chance. mating surfaces are never perfect.
a thin smear of hylomar assures you wont be taking it apart again in half an hours time.

[kman82]

True enough a thin smear of gasket sealant on my bmw gasket done the job nicely. I suspect i was just trying to fit the water pump like a spastic first time round but now its all good!

[aeberbach]

The old A/C belt was on so tight that I had to cut if off, as I couldn't fit it over the pulley to remove it. The problem was that I couldn't releive tension on the pulley, because the adjustment mechanism was maxed out in the "loose" position when the belt was fully tensioned! I read about "rolling on" the belt, which is where you put the car in gear and have someone push it so that the pulley turns, making it easier to slip the belt on. I tried this, but my new OE belt was so hopelessly short that even this didn't work. I finally got fed up and went to the auto parts store and bought a Gates 1/2 in. (12.5mm-13mm) width belt that was 2 inches longer than the OE belt. This one slipped right on. I tensioned it and it's worked beautifully ever since. Go figure.

Exactly what happened to me! I had to cut the old belt off and found the new belt supplied by Pelican as the right one for my car too short to go on when all the AC bolts were loose. I got the belt on by placing it partially on the pulleys and then turning the engine while holding the belt in place, forcing it to follow the groove and go on. But it is way too tight. I think going for the slightly larger belt and adjusting might be very good advice.

[kman82]

tut tut tut. That'll teach you for having luxuries such as AC!