1999 Volvo V70XC Variable Valve timing problem?

[many volvos]

My crank gear jumped the timing belt, when it was real cold outside. The camshaft gears both showed 5.5 teeth off. First question, does anyone know for sure if this damaged the valves? It appears that you have to be 6 or more teeth off, to damage anything. Is this correct? The engine spins fine with the starter and it wants to fire, but will not start. I took the belt off and reversed the cams to their marks and the engine will only turn in reverse 360 degrees, but only moves 270 degrees clockwise. Next question is if the valves are bent and interfering with rotation clockwise, why can the engine turn counterclockwise?
A tech told me you can not turn the engine counterclockwise or it will screw up the CVVT. Is that correct and if so, what does it take to correct that problem? I can not get the cams to align up on the back end of the engine, to install the locking tool, as the exhaust cam will not reverse far enough to be in the correct position, even moving the exhaust cam gear to the right, in the variable range. Is this due to built up pressure inside the CVVT, that needs to be relieved or is there some other restriction, that presents the exhaust cam from moving in reverse? I have had a mechanic look down the cylinders through the spark plug holes with a snake type camera and he saw no damage inside and no dents in the top of the pistons or bent valves. I do not want to take off the head, unless I know for sure there is an internal problem and it is not just a variable value timing issue.

[draser]

From this forum, it takes about 2 teeth off and valves start hitting. But if boroscope did not see marks perhaps you got lucky. So, are you saying that front sproket marks line up to cover marks and crank sproket valley lines up to block mark but rear slots are not horizontal? If that is true at some point one of the sprokets was removed and put back slightly off. Can you post pics of front sprokets all lined up and slots in back to see how much you're off?

[Ozark Lee]

You can, and actually you will have to, turn the engine counterclockwise to set the CVVT preload. It sounds like you are still off on the exhaust cam though since you should be able to turn the engine either way for a full rotation.

The chances of not having valve damage with the timing belt off that far is pretty remote but I would certainly exhaust every effort to try to get the timing back before the next step, which is to remove the head.

Here is what you need to do.

Get the crankshaft lined up to the mark. Double and triple check that you have the notch on the oil pump centered between the two microscopic marks on the harmonic balancer.

At this point you should be able to rotate both of the camshafts a full 360 degrees without any interference.

From there rotate the camshafts clockwise to the timing marks at the 12:00 position and install the timing belt. Be sure it is taught between the idler roller and in between the camshafts and tighten the tensioner.

Next rotate the engine 360 degrees and double check that the marks are still lined up. If they are lined up continue another 90 degrees clockwise and then rotate the engine back counterclockwise to the timing marks.

Loosen the tensioner and remove the timing belt from the camshafts.

Re-thread the timing belt back on, starting at the intake camshaft sprocket and when you get to the exhaust camshaft rotate the outer sprocket to the point where the timing mark on the sprocket is lined up with the timing mark at the 12:00 position on the cover. On the exhaust camshaft the outer portion of the sprocket moves independently from the center of the hub.

At this point the three bolts that hold the outer sprocket should not be at either stop on the slots on the outer sprocket.

Adjust the tensioner indicator to be between the tabs, in the window as it were, and tighten the tensioner bolt.

At this point I would go ahead and crank it through a couple of revolutions to see if anything is hitting. If you don't hit anything, try to fire it up.

...Lee