Discovered today that my cambelt tensioner pulley had collapsed (the ball bearings have gone all over) ,the belt has melted the cam cover where it was rubbing it and my crank cams are all out of time (V40 T4 1998 105kmiles). I pulled it all apart hoping that if i replace the tensioner and belt that no valves have been damaged. my only problem has been trying to remove the centre nut on the crank to get the accesory pulley off the crank. I did a search and found that some cars just need the four outside bolts removing to get to the cam pulley - is this the case on a V40 ?
I have left it soaking over night with WD40 penetrating oil and was going to try a bit of heat in the morning if it still won't shift. Is there anyway of seeing the timing marks on the crank pulley without removing this nut and is it a normal thread i.e. loosens anticlockwise as the manual doesn't say.
Alledgedly my local volvo repairer changed the belt and tensioner at the 80k service - can they fail this quickly or is there an easy way of telling if it was changed ? Should I also change the idler pulley while I'm at it.

Most of the time people use an impact to remove and install the nut.

You should be able to see the marks if you look at the lower crank pulley if you look by the block.One mark is on the block and the other is on the inside of the pulley.


It is possible that it could have worn out early.Yes I would replace the idler at the same time so you don't have to take it apart again.

Thanks for the fast response. Still didn't shift it this morning but noticed the timing marks you said about. Thought putting heat on it may damage the oil seals so gave it a miss and then noticed a small half moon shaped ally cover that goes below the crank pulley.
Having removed this with the two bolts that hold it - it is possible to take off the belt without removing the outer auxillery pulley.
It's a bit of a fiddle but I managed to get the new belt on and put a new cam belt tensioner on.
Seeing the allignment marks is pretty difficult but I noticed two cuts in the teeth of the crank pulley and a large blob on the aux pulley inside. - you need lamps/torches to see them.
Also the guys who did the last cam change marked the cam pulleys with nail varnish so it made it easy to line them up. I couldn't see any markings on the cam cover for the cam pulleys ???
Tightened it all up and then replaced the cover. Put all the other bits back and tried to start her up.......................

It's fine ! it would seem that on the T4 engine that there is enough clearance between the valves and pistons to not do damage - I would imagine this has to do with the low compression ratio of 8.5 to 1 meaning the piston doesn't rise up as far. No more worrying about the cam belt breaking then.

Having taken it for a blast for a couple of miles all seems ok. Hopefully somebody can use this info if it happens to them. The warning sign was a strange scrapeing sound on idle that dissapears if you rev the engine. The parts department at my local volvo dealer had never seen one go like this before - could be a one off , a bad batch or just was never actually changed at the 80k service as it should have been. Anyway I'll sleep better tonight.

You got very lucky somehow The engine 99% of the time bends valves.

So you fall into the 1% which is very lucky.