What would cause oil to pool on top of the head?

It's always there. I've replaced the crankcase vent box and all the related hoses.

'96 850 turbo.

 

Hello Pollock,

Oil on top of the head is one of the chronic problems to 850s. The oil filler cap gasket is of poor quality and as far as my 850 was concerned, I had to replace it at every other oil change. Another source is the dipstick O-ring, but this one is located below the top of the head, so I assume it's the cap gasket. However, one person has reported that he had a crack in the filler neck (according to him, the filler neck turned a bit as he tightened the cap), and he managed to repair it with JB Weld. The worst case scenario is probably something like this, as the head is aluminum and certain locations are made very thin so they could develop cracks.

I would wipe clean the oil, replace the cap gasket and see what happens. In the meantime, I believe other people would be able to jump in and provide you with other solutions that I may be missing at the moment.

Good luck,


JPN

 

Agree with JPN. Change the rubbergasket or the entire filler cap. Agree also that no matter what, every now and then we have to change it. Definitely is of poor craftsmanship.

 

I had the same issue and as mentioned by others, I changed the oil cap gasket and it cured the problem. I now make it a point to change the gasket at every other oil change. FCP Groton has them for about $2

 

I've changed that gasket once in 22 years of owning Volvo's. And that was just last month on the one I just bought. I just don't get it.

 

It doesn't seem like that gasket should HAVE to seal the oil in. Seems like it was intended more to keep dirt out.

 

You may be right, I don't know of any other vehicle that has so much leak from oil filler cap. It may only be cured by servicing the PCV related components. I am also suspecting the cap itself; it is of peculiar design and it seems to have spring (?) mechanism to it as you see a "cross" type metal tangs (it may only be there forpositioning purpose). If it still leaks after doing a complete PCV system servicing, the lastresort would be to wait for Tech's reply or call the engineering dept in Sweden[8D].


JPN