Thread: Thought i had joined the broken crank club but NO!

1 step forward 2 steps back.. fitted new oil pump and sorted broken rockers and cam sprocket , fitted it and timed it put an old belt and tensioner on that Dazza td5 kindly gave me, rotated the engine and just short of 1 rotation its locking up..

Im sure the timing cant be out as rotating it back from where it locks up i can get all 3 timing pins in on my marks .

The thing im unsure of is if i try and continue to rotate it back further it locks up again..

Any suggestions on things to check before i proceed to the next step of heads off..

Cheers Bulletman

Originally Posted by Bulletman

1 step forward 2 steps back.. fitted new oil pump and sorted broken rockers and cam sprocket , fitted it and timed it put an old belt and tensioner on that Dazza td5 kindly gave me, rotated the engine and just short of 1 rotation its locking up..

Im sure the timing cant be out as rotating it back from where it locks up i can get all 3 timing pins in on my marks .

The thing im unsure of is if i try and continue to rotate it back further it locks up again..

Any suggestions on things to check before i proceed to the next step of heads off..

Cheers Bulletman

You will have bent valves. Have you checked for valve binding? Cam rockers snap because the valve hit the piston and the force went into the cam rocker. You can’t go from that to happy. You’ll have bent valve stems and damaged valves seating surfaces.

If you say you’ve timed it right then you probably have a jammed valve hitting a piston

He checked unloaded valve heights but.

Let the cams loose and wind over with all the valves closed.

If that works its timing

Is it doesn't, it's the head

When it locks up. Put a scewer in the glow plug or injector hole and work out which head has to come off

Originally Posted by DiscoJeffster

You will have bent valves. Have you checked for valve binding? Cam rockers snap because the valve hit the piston and the force went into the cam rocker. You can’t go from that to happy. You’ll have bent valve stems and damaged valves seating surfaces.

If you say you’ve timed it right then you probably have a jammed valve hitting a piston

Im not the lucky backpacker who does no maintenence and somehow it fixes itself..
I fully expected it to have valve damage but thought i would see if the LR gods were shining on me but as usual they dont seem to be..

How do i check for valve binding ?

The car has cost me plenty so far so pulling the heads and doing a head overhaul is just another piece i expected, but hoped for some lotto style luck ... but as usual its not to be..

Cheers Bulletman

Originally Posted by josh.huber

He checked unloaded valve heights but.

Let the cams loose and wind over with all the valves closed.

If that works its timing

Is it doesn't, it's the head

When it locks up. Put a scewer in the glow plug or injector hole and work out which head has to come off

I rotated it with injectors out so i should be able to do as you say..

Im a bit confused as to if i can rotate with all the valves closed how does that tell me its timing not a valve ?

Appreciate the suggestion which i will try..

Cheers Bulletman

If you're lucky, it's possible the cam chain pulled the tensioner down hard enough when it had its "moment" that it skipped a tooth or 2, enough to lock up on the intake cam.

If it locks up with the cams backed off on that side, put some compressed air down the injector holes ( keep in mind the piston might want to "bottom"), and listen for air coming out the intake ( one person job ) or exhaust ( 2 people ) on each cyl.

If all that checks out try the other side.

If you can rotate it with all the valves closed then it has to be timing because a badly bent valve would still lock it up with the cams backed off.

Good luck.

Apologies if I've missed something as I haven't read through the whole thread, but have you checked cam timing / Valves on both sides?

Originally Posted by discorevy

If you're lucky, it's possible the cam chain pulled the tensioner down hard enough when it had its "moment" that it skipped a tooth or 2, enough to lock up on the intake cam.

If it locks up with the cams backed off on that side, put some compressed air down the injector holes ( keep in mind the piston might want to "bottom"), and listen for air coming out the intake ( one person job ) or exhaust ( 2 people ) on each cyl.

If all that checks out try the other side.

If you can rotate it with all the valves closed then it has to be timing because a badly bent valve would still lock it up with the cams backed off.

Good luck.

Apologies if I've missed something as I haven't read through the whole thread, but have you checked cam timing / Valves on both sides?

I had 1 broken cam chain and 1 that had jumped teeth so i have lined up both cams as per the manual that has the different colour links aligning with the slots on the cam toothed wheel ? Both side line up and both slot into the timing pin slots pretty much when they are at the 12 oclock position..

I will back off the cams and see if i can rotate the engine next but i cant see how timing can be out but i have never worked with overhead cams so i could well be doing it wrong..

My initial thought was timing but only 1 hole lines up on the fly wheel so i can only assume #1 has to be tdc.. then its just a matter on making sure the cams are correct but i cant see how you can be 180 degrees out on that set up.. but more than happy to be shown that my thoughts are incorrect..

I was going to do a leak down but decided on doing a rotation first just to see if it would but i cant get 1 full turn of the crank only about 7/8 before something locks it.. i can actually hear it but to pin point is very hard..

Thanks and cheers Bulletman

Originally Posted by Bulletman

I had 1 broken cam chain and 1 that had jumped teeth so i have lined up both cams as per the manual that has the different colour links aligning with the slots on the cam toothed wheel ? Both side line up and both slot into the timing pin slots pretty much when they are at the 12 oclock position..

I will back off the cams and see if i can rotate the engine next but i cant see how timing can be out but i have never worked with overhead cams so i could well be doing it wrong..

My initial thought was timing but only 1 hole lines up on the fly wheel so i can only assume #1 has to be tdc.. then its just a matter on making sure the cams are correct but i cant see how you can be 180 degrees out on that set up.. but more than happy to be shown that my thoughts are incorrect..

I was going to do a leak down but decided on doing a rotation first just to see if it would but i cant get 1 full turn of the crank only about 7/8 before something locks it.. i can actually hear it but to pin point is very hard..

Thanks and cheers Bulletman

That sort of force can easily bend a cam on these, maybe get it to the position where it locks up then back off the cam caps ( 1 side at a time ) and see if it rotates further.