Possible slipped Timing Belt (1.8t)
 

How'do folks :}

I've mentioned this in a previous post (1.8t misfire)

I suspect the Timing Belt may have slipped on my 75 :o

I may be wrong - however, this has me a bit concerned r.e other potential causes of my initial misfire - I don't want to run the engine at all now, so won't be trying new plugs/coils...


r.e a slipped belt - If a belt HAS slipped - is it possible to diagnose using the timing marks ? :shrug:

I was thinking - if the belt has slipped - i'll be rotating the crankshaft in Vain :shrug: as the marks won't line up :shrug: - or would it simply be a set number of rotations of the crankshaft would guarantee a thorough check ? ....:shrug: I'm not sure if that makes sense as to what my concern is.


my current thinking is - I have to just go ahead with a belt replacement - and hope there has been no damage caused - if there HAS - i'll find out after replacing the belt :shrug:


what damage is likely to occur following a belt slipping and timing being off ?



Paul.

Firstly i would check all timing marks line up as they should that way you can be sure everything is ok.:}
Then you can start to find the the cause of the misfire.:shrug:
If the belt has slipped it could be drastic:eek: or you could be lucky & no damage at all:D

If you turn the engine so the front pulley mark lines up - the cam belt change one not the TDC one - then the lines across the cam pulleys should show if it's all in sync or not. I think a stock engine can be one tooth out without causing contact.

If there had been any piston/valve contact and a bent valve you'd have a misfire or uneven idle. Mine sounded like a Subaru flat four at tickover when I bent a valve.

Re belt
 

Take a look at my thread in the 'Tech help', 1.8 belt disaster to see what you are facing, good luck!

I pulled the top cover off earlier had a wee look - nothing much to report - other than maybe the tensioner seemed off it's mark - there was a maybe wee bit slack in the belt :shrug: not too sure

I don't have a 22mm?? socket for the crank pulley - and it got a bit cold and dark - i'll acquire a 22mm socket and rotate the crank to check if the timing is off.

I'm of the feeling - i suspect it has slipped - so i should go ahead and replace the belt with timing/tension correct - fire up the car......:shrug:....and see if any damage has been done from there.

what's the thinking on this ?

if any damage has been done it's already done - and i'll know right away :D

I think i will have occured some damage to the valves(?) as i heard sounds you don't want to hear - didn't run for long tho :shrug: who knows i guess we'll see.





Paul.

Paul, don't change anything until you have verified by the marks that the belt has actually jumped. If it's not loose, jumping a tooth is much less likely.

Good luck,
Glenn

:cool: i'm going to get a 22mm socket (sure that's the size - i'll confirm) so i can rotate the crank and check timing ;)

I do think there was a bit excess slack :shrug: and the tensioner was off it's mark - suggesting it's not tight enough.


Paul.

Isn't there a timing mark on the outside (plastic) cover? If so, you could check the timing without removing the bottom pulley.:shrug:
EDIT. Re-read. I see that you are just using the socket to rotate the engine!

You will have a small amount of slack in the longest section of the belt you could twist the belt about 45 degrees.
Good luck.

Is that WILL have or SHOULD have ? :shrug: i.e - should a properly tensioned belt have 45degrees of twist ?



I'm no further forward today - other than i've been preparing for the "Inevitable" :D - I'm pretty sure with what i experienced that - timing WAS off causing initial misfires/hunting idle and, whilst chasing faulty coil/plug possibilities and running the engine - Metal on Metal contact WAS heard :cool: it's a GREAT sound :getmecoat: not....lol

so i'm expecting/preparing for a head off valve replacement ;)


I still plan to check timing before i start pulling her to bits:D;) - if i can i'll pick up a 22mm socket over the weekend - :o funds are that low i can't afford a £7 socket at the minute :duh:



I'm not sure what i'll do if the timing lines up :shrug:

I'm hoping to find timing IS off - in this case i think i would just accept that valves have bent - rather than fit new belt/tensioner and hope for the best - I heard contact and from the way it was last running, i'd guess a few are stuck open.


I think in this case i'd like to have a go at repairing this myself :cool:


It may take a week or 2 or 3....lol.... Once i have funds for all the parts i'll need - it adds up :eek:......




Paul.