random misfire

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mcdjl

Original Poster:

5,438 posts

194 months

Wednesday 29th July 2015
quotequote all
Hi, my 2002 v70 had had an oil leak into one of the pistons via a spark plug for some time now. As a result it uses oil to a varying extent. A pressure test said all was fine so I carried on. It's now developed a random misfire which is worse under load but seems present at idle, though barely noticeable. This came on suddenly with no apparent warning. The exhaust is quite sooty, but this had coincided with the oil getting used rapidly. Topping the oil up hasn't made a difference.
As this is random it would seem to be likely to be air or electricity, . Or the fuel pump. I'm trending away from the latter as while it's down on power it'll still pull. Does anyone have any suggestions for how I can chase this....our shall I look at new cars?
Cheers!

C70R

17,596 posts

103 months

Wednesday 26th August 2015
quotequote all
mcdjl said:
Hi, my 2002 v70 had had an oil leak into one of the pistons via a spark plug for some time now. As a result it uses oil to a varying extent. A pressure test said all was fine so I carried on. It's now developed a random misfire which is worse under load but seems present at idle, though barely noticeable. This came on suddenly with no apparent warning. The exhaust is quite sooty, but this had coincided with the oil getting used rapidly. Topping the oil up hasn't made a difference.
As this is random it would seem to be likely to be air or electricity, . Or the fuel pump. I'm trending away from the latter as while it's down on power it'll still pull. Does anyone have any suggestions for how I can chase this....our shall I look at new cars?
Cheers!
That sounds like a really strange kind of problem. How did oil get in via the spark plug in the first place?

mcdjl

Original Poster:

5,438 posts

194 months

Wednesday 26th August 2015
quotequote all
No idea! I sold the car in the end, well px'd it for at 9-5 which seems to have a propensity to drink oil.