Cambelt jumped a couple of teeth

**tuit** · 01-06-2009, 05:02 PM

I have a gen3 3sgte and the other day the engine stopped while pulling out of a carpark. After checking all the usual suspects we found the cam timing out by 3 teeth.
The exhaust and inlet cams were still in time but were retarded by 3 teeth when check against the crank. The motors only run 10k km since complete rebuild.
So my questions
1. What could cause this ?
2. Is there likely to be any damage ?

I've reset the cam timing and the cars running again but I'm understandably nervious.

**IN 05 NT** · 01-06-2009, 05:13 PM

belt tensioner loose/faiiled?.............

put the belt back to where it should be and see if she starts......wind it over a couple of times to make sure its not locking up on a bent valve 1st....not sure if these are an inter-fearance motor? (spelling

)

**thechuckster** · 01-06-2009, 06:18 PM

i think you have to get to gen4 before it's an interference motor - but i'd let someone confirm that.

Tuit: are you sure there are no teeth missing on the belt? and the tensioner is still within specs?

**TooF** · 01-06-2009, 10:09 PM

the tensioners on the 3s are a fairly comples beast.l certinaly with the gen2 you need to get the feeler gauges out to do it right and even the g3 are a bit tricky requiring you to press the tensioner spring into place. =

sounds odd but was it all put in right to start with ? generally a timing belt that is fresh and undamaged wont jump unless the belt is loose or something has stopped a camshaft moving.

**tuit** · 02-06-2009, 10:53 AM

tuit: are you sure there are no teeth missing on the belt? and the tensioner is still within specs?[/QUOTE]

I carefull checked all the teeth and removed the tensioner to make sure it operated correctly - not sure how much travel it should have but mounted back up it's less than 50% thru it's travel.

**petergoudie** · 03-06-2009, 12:19 AM

(1) This can sometimes happen in the rebuild if you turn the engine over with a spanner anti-clockwise or backwards. You should always turn them over in the direction they were made to go. (2) Some tensioners have a plastic tab or piece of wire holding them retracted during fitting. These have to be taken out before you put the cam belt cover on. If your's had one may be you didn't remove it.

**YLD-16L** · 03-06-2009, 09:33 AM

Often happens too when people park on a hill in gear where the car wants to roll backward and they have it in a forward gear or it wants to roll forward and they have it in a reverse gear.