Bad luck Flea. My coupe is weeping in sympathy

Don't think its engine mounts (or at least not worn engine mounts)

My mounts are pretty worn now, especially the lower rear. I often take my car past 7,000rpm, with few ill-effects (last time I did it, a water hose blew )

If the belt is shredding along its length, its indicative of it coming off either a pulley or a tensioner. Clearly, you have several to choose from, but my guess is that one of the elements of the belt run is out of true and its this that's causing the belt to slip off.

the fact that some failures have simply been the aux belt falling off away from the engine and some falling into the engine suggests that there is something causing sideways deflection of the belt. If it was just loose (but straight) it would flap around a bit, but should stay on the pulleys and tensioners.

I'm convinced that Flea's state of tune is not the issue. There are too many other cars running similar revs or similar bhp that haven't suffered for it to be caused by these factors alone.

As I said before, if it was solely caused by lifting off the throttle, it would be happening to more owners (especially as the latest failure was well within the rev limits of a standard Coupe)

The other alternative is to use the stilo abarth engine mounts where the belt arrangement is completely different. I had the aux belt go on my stilo and it did not take out the timing belt (that's not to say that it might not go) I guess the mounts may also be the same as the 1.8 147/156/punto HGT engine.

The pulley guard just reduces the risk. Without full enclosure of the belts nothing is guaranteed. Before the pulley guard in 90% of occurances the timing belt went, I guess with the guard it will reduce it a lot.


As i mentioned earlier I bet you've never changed your cam timing pulleys and if you want to rule out stuff the first thing is to change them and tensioners, not try visually see as you will not visually see anything unless it is so bad that it will last no time at all. You will not see a 1/2mm movement, but you can be sure that will shorten the belts life

Cam pulleys? i.e. the vernier pulley or the crankshaft cambelt pulley? I spoke to Barbz earlier and he is pretty confident that everything is ok down there having checked it before he left. I have to say the belts never look like they are perishing, no visible wear at all.

Leight, did you hit the limiter? If you remember mine went on the rollers at PT when it bounced off the limiter and I suspect it's the abrupt on off power that causes the belt to go AWOL.

Is it possible to get a picture a bit further away from the engine as I wonder if there are any other points where we could fashion up a stationary protection plate to compliment the one Barbz made.

Yes I remember you doing this!! I didn't hit the limiter this time and invariably don't unless on the drag strip That said, I think coming off the throttle at high rpms is effectively the same as the throttle goes closed and the injectors are cut so the engine braking is pretty severe.

I'm going to look into a better protection plate as while it only treats the symptoms I think this is the easiest solution to eliminate the risk totally regardless of other measures to stop it happening in the first place which may take time to figure out.

When I was at Guy Croft just before xmas he had been speaking to the Gates' the chaps who make hoses and belts regarding failures, the situation is incredibly complex there's a thread on it on his site.

Flea could there be a certain amount of run out on the crank pulley - maybe its creating extra fatigue in the belt, fatigue is the thing that kills belts so power/torque will always be a factor. Looks like wider belts are the only option - space will be the issue for sure.

Rich

Is there any way that it could be converted to run a chain?

someone mentioned a chain previously. They are more noisy and they require lubrication.

there not noisy on bmw so if it was done right i dont think it would be imo,remember i no sod all so dont shout

Wouldnt source of lubrication may be slightly cheaper than fixing the product of snapping belts?

Anyway im REALLY being thick here but could you not open the bonnet, bring the engine on to a decent amount of revs and strobe it to look for play?

Phill

Point one finger on his nose and one at pfoe in the style of Lionel Blair.

I think that might be an idea.

D-Day... to be bent or not bent, that is the question?

really hope its not too bad, fingers crossed!

Same here.

Not on here so much these days so only just seen this thread. Sorry to read it Flea.

really hope its not too bad, fingers crossed x2

Any news?

Ross

Yes... I found out on Monday that the valve clearances were way out i.e. bent valves, so no point timing it back up. Today the head came off and this is the view of 20 bent valves

Thankfully the pistons and rings are ok so it's a top end rebuild.

Doing anything with the big ends?

Will be dropping the sump and pulling the pistons to check it all.

Oooh bad news Flea

What are all the little marks on the valves?

its where they've been thumped with a forged piston

The sparkplugs look a nice colour...

limited consolation though...

Oh yes ofcourse. Got confused by the colour of the inlet valves (bronzy ish)

Yes the marks on the valves are from the pistons. Thankfully the pistons are all in very good condition along with the rings. There is zero sign of detonation (can normally see slight pitting on the piston crown near the edges) and the fueling is pretty much perfect with a nice tan colour on the inlets and the plugs. It's nice to see that at least!

Some of you may be wondering about why I have 3 electrode NGK 8 plugs in there instead of single electrode iridiums. Well I have actually found them to be more consistent at high boost than the iridiums which have been the cause of my missfires on two separate occasions!

Hope you get it sorted soon

Ditto Flea.

Ross

Arse - good luck with it Leight. Who's doing the work on it?

Just had a thought about this…………. Bare with me……

Flea said that his belt was coming off when he was applying/dropping the clutch (not necessarily at high revs though).

Is it possible that there is very sideways play in the crank? When the clutch is applied (believe Flea has a helix paddle) it is pushing the whole crank back a little, hence the crank pulley is then out of line slightly with the other pulleys and the belt snaps or comes off?

Suppose you could check the end play of the clutch by jacking up up and applying the clutch and then releasing it and see if the pulley moves.