I am not aware of any sealant needed on the bolts on the idler pulley on the 960. If it's leaking oil, I'd bet either the cam or crank seal wasn't installed correctly or the shaft may have been gouged during removal of the old seal. Alternatively, the cam cover gasket (anaerobic seal) can leak although I would think this would be rare. When I replaced the head on our '97 960, I used Victor Reinz seals and they are holding up well.

How is your PCV system? If this is plugged, it can cause oil leaks. When I did the head, I replaced the whole system and it was amazing what poor condition the hoses were in after 240k miles.

Dear Volvo426,

Hope you're well. My comments relate to a cam seal leak on a 940. Oil wet the top of the head projection, under which is the water pump.

hen I removed the cam sprocket, there was no sign of oil leakage on the face of the head. Yet, the cam seal - red, aftermarket (put in by prior owner's mechanic, 15 yrs / 70K miles ago) - was so loose, that it took minimal effort to remove. I put in a Volvo brand Viton seal (#6842273). There has been no sign of leakage.

The lesson: a seal that has failed - or is improperly installed - is likely to leak. The idler pulley seal may have been seated slightly "cocked", i.e., the seal's axis is not parallel with the axis of the idler pulley shaft. Also possible: the seal's inner lip was kinked or folded during installation.

In short, I'd have replaced the idler pulley seal and see if that solves the problem.

I used the B230 engine crank pulley counter-hold tool - usually used to hold the crankshaft, while the crank pulley's bolt is removed/tightened - to hold the cam sprocket, while I removed (and tightened) the cam sprocket bolt. I do not know if this tool will help with that, when it comes to removing the idler pulley's bolt on a B6304 engine.

Hope this helps.

Yours faithfully,

Spook