hi

my mums car recently broke its cam belt


its a 1.6 vauxhall astra M reg.


do any of our resident experts know if this engine crunches itself if the belt breaks, or does the pistons miss the valves....?

according to mum, the car just lost power and there were no nasty noises.

Its the belt for sure, I can see its snapped.


atb

steve

[Edited on 7/12/03 by stephen_gusterson]

A friends wife had one that broke them several times and it never had a problem after replacement. It was caused by the water pump, they found out eventually, bearings had gone and the belt was running off.

yours, Pete,

Stephen, got one of them, its my toolbox and the third one ive had, bust a couple of belts and just replaced it, try turning the engine on the crank pully bolt by hand, trust me u will know if somthings whacked if u here crunching noisies
Shug.

sounds good so far!

thanks

Steve, as far as I remember, they always bend one and ususally 3 valves. Once you have sorted the head and you put a new belt on, always renew the water pump, it acts as a tensioner, and is guaranteed to leak once disturbed, it has a big O ring which perishes, you can replace this, but the ally pump in an iron block does the usual disolving trick. The pump is dead cheap though.

Steve, sorry I didnt see this earlier....

As already mentioned, sometimes you can be extremely lucky and the engine suffers no damage whatsoever.
You could be just lucky, and find that the engine has snapped a couple of rockers, with no further damage. These can be replaced without dismantling, IF you have the special tool. The tool is basically a valve spring compressor, that bolts to one of the rocker cover bolt holes. The toll can then be tightened down onto the spring cap, pushing the valve down and allowing replacement of said rocker. SP sell em, or alternatively make one...
Or you could be unlucky, and find it has bent valves....

IIRC the water pump does not have to be moved on a VX engine of this age, instead tension is adjusted by a plastic idler gear, which are very prone to collapsing, This may of caused the belt failure, and if it hasnt, replace them anyway. But check the pump as well, and if the money will stretch, fit a new one anyway. I have fitted loads of VX cambelts, only to find that the water pump is leaking a month or so later....

As for how the cambelt is tensioned, it may be best to refer to a manual, because the tensioner is a weird and wonderful thing.....

thanks for all the advice!

atb

steve

The 8v engines are bullet proof when it comes to cambelt snapping. Tho the 16v's are not. Especially the 2.0 16v, which will bend valves,etc with a broken cambelt. i would imagine the 1.6 16v would be have similar problems.... just hope yours is an 8v

I didnt take that much detail in - but the placcy cover over the belt was pretty wide at the head, so I would put my money on it being a 16v

atb

steve

8v engines, remove rocker cover check for broken fingers.
If broken fingers, undo head bolts remove cambox only (carefully) replace broken fingers and missing thrust buttons, replace cambox(carefully) AND REFIT old head bolts to original spec, replace cambelt AND waterpump/idlers/tensioners. turn engine by hand if ok compression test/start.
If fingers NOT broken replace cambelt AND waterpump/idlers/tensioners. etc. etc. etc. etc..

If 16v remove head and cry. replace cambelt/waterpump/idlers/tensioners after crying while refitting head.

If a head requires reworking I would recommend Cylinder head services in Northampton.

ATB steve hope this is not tooooo late & helps.


Enjoy

Have 93 1.4 astra 8v
I was very very unlucky

one of the cam shaft bearings seized which stopped the camshaft, which twisted the timing belt sproket off the camshaft, which bent valves and ruined pistons and rockers

[Edited on 22/12/03 by liam.mccaffrey]

Update

mum got her car fixed

12 bent valves of 16

cost 1100 quid

expensive cam belt change!

atb

steve