Hi guys. Helping my son replace blown head gasket. All was fine until I went to refit the camshaft to the sprocket but it doesn't line up (about 10mm). Prior to dismantled it I lossened to tensioner, tied the chain to the sprocket and inserted a large punch through the sprocket to prevent it from turning when undoing the bolt. Does it mean the chain has moved - jammed or is the tensioner stuffed. Got me frustrated. Any ideas would be great thanks

have you pulled the tensioner out? i mean all of its peice's

10mm is exactly the distance between the teeth on the cam gear, im not sure how distance between teeth on the crank and aux sprocket but its most prolly slipped a tooth.

Best way is to line up the balancer mark with the timing cover notch which is TDC of piston 1, and make sure the cam gear mark is sitting within 3mm above the head when fitted to the cam. If its out a tooth, then the cam gear mark will be out enough for you to notice.

BUT old harmonic balancers can slip over the years and cause the mark on it to show false Top Dead Centre of piston 1.

So prolly a good idea to check the TDC of piston 1 yourself:

Get a long socket extension or long screwdriver, tape on some paper around it and draw some fine lines up it to use it as a gauge. Tape down a paddle pop stick or something on the top of the head above no.1 spark plug hole to make it easier to see when the gauge moves up and down

Turn the crank with a 22mm socket and breaker bar until your getting close to the pulley mark lining up, also make sure its on the rotation where the cam gear mark is coming onto the right side.

Stick the gauge you made in the no.1 spark plug hole and and hold firmly down on the top of the piston and upwards against the top of the spark plug hole. Turn the crank slowly and watch the gauge move up, when the moment it stops moving, make a mark on the pulley at the timing cover notch.

Now keep turning and note when the moment the gauge starts to move down. Make another mark on the pulley. Find the middle point inbetween these two marks and THAT IS YOUR REAL TDC POINT. You may have to rock the crank back & forth a few times to double check the points

So youve found the real TDC point, it may even be on the original pulley mark or its a fair way off the pulley mark which means its slipped.

Turn the crank to the REAL tdc point youve worked out, making sure the cam gear mark is on the passenger side. Now is the cam gear within 3mm ABOVE the head? If not, measure the mark on the cam gear if moving the cam assembly back or forward a tooth would make it right.

(note that the cam gear teeth are 10mm apart, so each tooth its turned will move the cam gear 10mm)

Hold on....... do you mean you cant get the sprocket to move close enough to the cam to bolt it on and your 10mm out?

If so, that means you didnt lock up the tensioner properly and its tightened up the chain. You must remove the power steering reservoir to gain access to the tensioner and remove it. Then compress it in your hands and refit it, then turn it anti-clockwise to release it

unless its simple, like turning the cam?

thanks guys, all the posts are spot on. I'm heading back down on the weekend so I'll check it out and post back. cheers

Yes the tensioner is a ratchet type not continuous, it must be removed from the block and reset. Unfortunately this requires removing the PS pump and bracket to access it