D5 (2005 on) Engine won't rev more 1500

[vanags]

Hi!

I and mechanics in service station don't know what to tray next. My timing belt on D5 diesel engine 2008 jumed by one tooth. They opened camshafts and found only one rocker not in place. Placed this on place, changed timing belt and seal ring on camshaft. Now engine not rev more than 1500. It sounds good but slow response from throttle pedal and no rev more 1500rpm!!! Measured presure on all cylinders is ~30 bar +/- 1 bar.

No fault codes on Volvo Vida now. Only from begining was fault on camshafts position sensor, after erasing it, not more reapears.

Is it possible by change of seal on camshaft, its gear is fixed in wrong position and so the timing is incorrect? Mechanics told me that there is very small amout of possible movement and this can't so influence work of engine if it moved by small amount. But according Volvo Vida, some special tools (plugs) are required by this operation - how important they are. And is it possible this done without it.

My suspections was also that exhaust camsahft is turned by some amout and now it works faster, then required, but after investigation I found that between camshafts are gears on anotehr end of camshafts. This is not traditional way, when timing belt is turning both camshafts.

And what else we need to check?

Volvo V50 2008 D5 engine.

[vanags]

Done! Changing engine head fixed the problem. Valve lifter places was broken - all 20.