This does not seem good 94 850 smoke and crankcase pressure

skloon · Post by **skloon** » 05 Apr 2018, 15:52

Driving my RN swapped 94 850 turbo it has about 175000km on the engine and runs strong, lately I swear that it has been smoking but had to tell as it has been cold and it could just be steam, today coming to work I could tell it was nice blue grey smoke when I got off the throttle. When I got to work I opened the hood and when I opened the oil cap it actually popped at me. The PCV system was done about 20000km ago all new parts so I don’t quite know where to start. I fear a head gasket but the cap is free of sludge, of course it will be cold as heck for the next few weeks so I will not be able to wrench too much but wonder what the heck is going on

Post by **tryingbe** » 05 Apr 2018, 16:09

I'd upgrade the hoses and drill the hole bigger.

viewtopic.php?t=77936#p418231

Post by **scot850** » 05 Apr 2018, 20:11

What oil viscosity are you running?

Neil.

skloon · Post by **skloon** » 05 Apr 2018, 20:37

Mobill one 0w30

Post by **abscate** » 06 Apr 2018, 01:50

Pull the dipstick and vent the tube to ground with hose to temporarily relieve crank pressure and save the seals. The Volvo seals, not those cute baby harp seals

skloon · Post by **skloon** » 06 Apr 2018, 09:19

So I drove to work this am with the oil cap off-the smoke seems gone but it was -17 so lots of steam, where is the pressure coming from and how does the smoke appear ?

Post by **scot850** » 06 Apr 2018, 10:06

That oil is way too thin for a 94. Try running at least a 5W-30 for winter as per handbook and 10W-30 summer (I think I got that the right way around). For my 2000 models they specify 5W-40 oil.

Neil.

skloon · Post by **skloon** » 06 Apr 2018, 11:23

Okay, the engine is out of an 04 so when I tear out the PCV system and replace I will do the spring oil change

Post by **scot850** » 06 Apr 2018, 14:23

Even for an 04 my friend that is too thin I would suggest. Our 06 XC70 specifies 5W-30 oil.

The later version of the PCV system typically has less issues but is not immune depending on servicing history.

Good luck!

Neil.