I have a 99 V70XC.

just noticed a puff of white smoke at startup after the car has sat a day or so. Clears out right away but it's really got me.

122K

any ideas?

 

Check the vent system.

 

Vent system?

you mean air cleaner, air inlets?

 

Not I mean the engine vent system(Vent box system on american cars known as PCV system)

 

Ahhh!

Crankcase pressure. Could be plugged somewhere? I'll check it out.



Any paticular spot they sometimes plug?

 

Could be anywhere it should really be removed and inspected. But also if a hose it bad or torn will do the same thing.
There is one hose in the induction hose just before the turbo that the elbow sometimes goes bad on.
Also see if you have a banjo fitting on the bottom of the intake. It is close to the power steering pump. If so there is a small hose that comes off the vent box to the intake check it in the bango fitting they clog there.

 

Ok,

Haven'T had time to dig into this but I tried starting it this AM with the oil filler cap off after it sat overnight. The puff only happens after sitting overnight. Am I thinking correctly trying to rule out high pressure in the valve cover?


It still did it.

 

I wouldn't if the vent system is plugged when you turn it off the oil will move and sit waiting for the next start up.

 

Thank you very much for the quick reply.


Not to sound dumb but you're saying taking the cap off at start-up is not a going to tell us anything?

Any good links with a step by step instruction on cleaning the PCV system? Haynes manual?

 

That really won't tell that much.
Start the car and rev it up some or hold it up some for a few minutes then let it idle and remove the cap and see if pressure releases.