Volvo 2.4t engine burning oil after engine braking / vacuum?

[Willber]

My 2002 V70 2.4 turbo petrol is burning oil after long periods of engine braking. It will give a puff of blue smoke which clears quickly when accelerating again after engine braking.

Car does not blow smoke at any other times either on boost / full throttle or after long periods of idling or in the morning on cold start (so I dont think it is valve stem seals).

The PCV system is good and I replaced the whole lot around 7k miles ago, still sucking in when doing the glove test.

I have read it could be the turbo 'seals' which are actually similar to a piston ring type seal within the turbo. A recon turbo is £150 and I can fit myself.

Does anyone else think it could be something else? I need to take the intake pipework off and see if excessive oil is in there and check the turbo for play.

I will do a compression test also to be sure but I am told these engines rarely have piston ring issues....

Thanks

Will

[dhutch]

Doesn't help a lot, but my X-reg nat asp 330ci also does the same.
Since I cured the weep on the oil filter housing it need about a pint every 4-6months or 3-5k miles.
Given the car has done 170k and most of its age seem to do the same or worse, ive not looked any further.


Daniel

[stevieturbo]

could be PCV related or valve stem seals.

I doubt it is the turbo.

What oil is in it ?

[Willber]

I dont think it will be PCV as I replaced the whole lot including the pipe which goes around the side of tue block. It sucks in at idle whereas it didn't before replacement.

There is oil on all the plugs so I am thinking it is stem seals now.

No play or excessive oil in the turbo or intake pipework

I think it may have been caused by changing the fully synth oil whereas it has always been run on semi before. I have ordered some Forte seal conditioner and will change back to 10w 40 semi to see if it helps ....

[stevieturbo]

Willber said:

I dont think it will be PCV as I replaced the whole lot including the pipe which goes around the side of tue block. It sucks in at idle whereas it didn't before replacement.

There is oil on all the plugs so I am thinking it is stem seals now.

No play or excessive oil in the turbo or intake pipework

I think it may have been caused by changing the fully synth oil whereas it has always been run on semi before. I have ordered some Forte seal conditioner and will change back to 10w 40 semi to see if it helps ....

Yes, but if it sucks in, it can also suck in oil if the oil/air separator aspect is not good.

If the plugs are oily, look for the source. ie. is the intake manifold or throttle oily too ? or associated pipework leading to that ?

[Willber]

Fair point but as far as I know if the PCV sucks in on a Volvo then it's good. I will however check the throttle body pipe for oil. Would it not smoke after idling if it was anything to so with the intake?

It only smoke on extended periods of engine breaking which again according to googles suggests stem seals.

Its all a bit strange to be honest as its always had regular oil changes and is (was) running a lot better than when I bought it with the fully clogged PCV