Fume vent pipe

[WillsMck]

Hi I have just driven a friends 1098cc which has been laid up for about 4 years. It was driving fine except after it was warmed up there is a constant escape of fumes from the metal fume vent pipe on the side of the engine. Actually I originally assumed it was steam, but I think it was exhaust. Has anyone any ideas about what I should do or investigate?

Thanks

William

[MarkyB]

It should be connected to the air filter at least, not open to air.

[WillsMck]

Thanks but this pipe is metal and runs straight down the side of the engine and is open like a drain down pipe

[phurn]

Sounds like the crank case breather, only there to relieve pressure in the case, nothing should come out of it! If it is then there's something up with the engine surely? Gas escaping through the piston rings?

[chrisd87]

Sounds like the piston rings could be in a poor state, as smoke from the breather pipe is frequently caused by excessive blow-by from worn rings. Carry out a compression check (engine hot, throttle fully open), and see if that reveals anything.

[bmcecosse]

Rings were probably stuck after lying unused. They may now be broken if the engine was started without first adding oil down the bores. Head off and pop the pistons to investigate. DO NOT RUN THE ENGINE !!

[Sam_Finlay]

What ^^^^^ bmcecosse said for definite.

[WillsMck]

Thanks but I fear the advice is too late as I drove the car back from the MOT tonight. It was only when I stopped and opened the bonnet as I could hear an unusual sound that I saw the escape of fumes from this down pipe.

[Sam_Finlay]

Has it seized then or was it still running when you switched the engine off?

Depending how long, fast and hard you ran the engine for will determine the extent of the damage you may have done. Someone correct me if I'm wrong but - if it hasn't seized then then the damage may be minimal. It will need a strip down to check it all out but you could still just be looking at a new set of rings and a decoke.

[polo2k]

How did the MOT go? if they passed it while smoke is coming out for a breather, I wouldnt trust it as a safety check ;)

[chrisd87]

If it's not listed as a reason for rejection in the MOT manual (which it isn't), they can't fail it. The tester can't make up the test as he goes along! Would obviously warrant an advisory and a chat with the owner, of course.

[WillsMck]

Started up this morning and no fumes. The fumes only seemed to appear after the engine was run for a while. This was the first time in six years that the car had been out. There are no abnormal noises from the engine and it seemed to be pulling away fine.

Thanks

William

[bmcecosse]

Would still suggest putting some diesel fuel down the bores and leaving it to soak through the rings for as long as possible - just to try to free off any sticking rings.

[WillsMck]

Thanks for the advice

William