Cambelt changed now bad noises?

test for even compressions

Look for water in the oil, oil in the water. The head gasket might have let go. Look for steam in the exhaust (after it warms up).

Worst case: hole melted in piston (that's what the noises suggest to me), but I can't see how that could have happened. Probably not the issue.

Good luck,

also a blow between two cylinders can sound like you describe, but again a compression test should show that

You probably have, but is the head torqued down properly?

Yes, and that is what is annoying, I did it all correctly, but it looks like the head will have to come off again. Alan.

It could well be that, I'll be doing a comp. test tomorrow, but unless the comps look about right, I think the head will be off again, which is a real pain, though all of the bolts will come off easily, so I wont be

3 hours underneath trying to undo the exhaust nuts this time. Alan.

Compression test done - 135, 225 220 215. So Cylinder 1 has a fault. Tested again, with a reading of 0. Piston is going up and down, cams are turning. So it is head off again(bollocks), to see what has gone wrong. It doesnt look like an head gasket fault as no leaks at all at that end, so either a dropped valve, stuck valve, or damaged piston crown. Depressed is a word that springs to mind. Alan.

Have you had the rocker cover off yet? If you removed the valves from the head I'd guess that one wasn't put back together properly and a collet's popped off, or a spring has broken, possibly.

Si

And that's the right answer - just got the head off again 5 minutes ago, with one of the brand new exhaust valves drooping. Luckily no major piston damage, so the car will not be scrapped this week, as was being planned earlier today.

Now, what about re-using the head gasket and bolts? They have been on for 3 days, with the engine running for 10 minutes.

I know both should be replaced, but is it really necessary?

Thanks Alan.

Not when the labour is free ;) You should change them both, but if the gasket is expensive and the old one is looking good................. most stretchbolts will go again, although you should check the overall length on some types.

I would be concerned about the valve guide (they can crack when a valve gets dropped), and obviously you will need to check that the new valve can seat properly

Well, this is a strange one. The collet end of the valve has broken off:

This was a brand new valve, it had ran for less than 10 minutes. As the engine had been run with it broken, there is some rubbing/wear marks at the break, so it is not clear if it was a crack, or manufacturing fault.

I'm presuming this is a makers fault, though am open to any offers on how this has occured. Thanks Alan.

Never seen that before. Paging Mr.Cheerful!

Si

This can be caused by incorrect collets (old ones on a slightly different design of valve). Or did you do anything odd during install that could have put a sideways stress on? I have seen people do strange things with levers and the like rather than get a proper valve spring compressor for instance. Can also be caused by a wild cam without the right valve springs. aaah, were all the valve springs right down in the head? if it has the wide brim valve seals were they right down? if it has shimmed valves were they in right? if hydraulic tappets were they cleaned out and fully collapsible?

if you are certain everything was correct then a faulty valve is possible, but very remote. take it to the supplier and see what they say.

Dave Baker would have some more good ideas and experience too.

Mrcheerful