When removing the dipstick when engine running, oily vapour coming out of the hole. is this blow-by and is this serious?

- (#245) Ivan Cousins, 20 Mar 05 14:26

It is blowby alright, but there are degrees... As long as there isn't enough pressure to pop the dipstic out of it's tube, or to cause problems with the turbo (blue smoke at idle), I wouldn't worry too much.

Didn't we find something iffy with the breath or yours a while back?

- (#245) david miller, 20 Mar 05 14:33

yes, it has always been a little smokey and use's a bit of oil ( about a pint every few weeks ).

- (#245) ivan, 20 Mar 05 14:37

Hmm, not so good then, maybe. You might try a flushing additive in the oil to see if the rings are sticky, but after that...?

Thicker oil to stop the blowby, or expensive fully-synthetic stuff to reduce vaporisation. Two schools of thought there.

Or re-ring it? yours is a facelift so it's probably worth doing (if you wanted to...), but on balance I'd probably drive it until it failed an emissions test.

- (#245) david miller, 20 Mar 05 16:57

These are the symptoms that I had from a cracked piston. Rising oil consumption was the main thing that I noticed, plus oily vapour blowing out of the valve cover breather into the air intake hose. Power, economy and emissions were fine. It got gradually worse over about 15,000km and then the exhaust starting getting embarassingly smokey and within 100km the crankcase pressure was enough to pop the dipstick up and spray oil around the engine compartment and some intermittent clattering noise could be heard - the piston finally separating, I imagine. It was still drivable, with the dipstick tied in, and is now going fine again after I replaced the piston - no other damage. I got the feeling that using various additives actually accelerated the final phase of the failure, it was just unfortunate that it was in the middle of a family holiday a long way from home.

That's my story, whether it's yours, Ivan, I can't say.

- (#245) Dave Mason (Sussex), 21 Mar 05 03:48

we are going to france at the end of june in the van so i suppose i should get it sorted. was it expensive?

- (#245) Ivan Cousins, 21 Mar 05 12:59

With hindsight I regret not sorting mine earlier.
Expensive? See Ace Answers > Engine mechanical > Piston. Broken piston to replace. I had time to plod through it myself - never done such a big job on a car before.
Step one would be a compression test which is not a big deal. Poor compression would confirm blowby and lead to removing the floorpan, head and sump - which a mechanic will do in a day. You then know what's broken, the state of the head, valves, pistons, rings, injectors etc and can plan the repair, plus any desirable reconditioning on the way - head surface, injectors, belts, temp gauge mod, etc. Once you've got the bits a mechanic can get it back together in another day or two.

- (#245) Dave Mason (Sussex), 23 Mar 05 03:56