Page 1 of 1

Blue Smoke

Posted: Sun Jun 21, 2009 5:44 pm
by whenisayjump
I have been looking at a minor that failed it's MOT on 'blue smoke' from the exhaust. I have been told this is thought to be because it's been driven very little for a year.

Could this be the cause?... or is it something more extreme like piston rings? (I know it's had a new head gasket in the last year)

Posted: Sun Jun 21, 2009 5:56 pm
by MarkyB
If the smoke appears after you rev the engine it's probably ring/bores.
If it only happens when the engine is started having stood for a while it is probably valve seals/guides.

Posted: Sun Jun 21, 2009 5:58 pm
by whenisayjump
I would imagine both are pretty major though.

Posted: Sun Jun 21, 2009 6:08 pm
by MarkyB
If the bores are worn you need new pistons and a rebore, this get pricey.
Valve guides you can do yourself.
Either way knock plenty off the price for the aggro.
If the engine is that badly worn it suggests a general lack of maintenance so grease points may not have been maintained either :o

Posted: Sun Jun 21, 2009 6:42 pm
by dalebrignall
wyns make some stuff you can add to the oil to stop it smoking.i dont know if it works,have you got good oil pressure,if not sounds expensive.

Posted: Sun Jun 21, 2009 6:45 pm
by whenisayjump
This is on a car I'm looking at buying. Essentially it needs the suspension mounts welded (all), and it has a dodgy earth so the lights are behaving funny.

It's just the blue smoke that worries me. They say it's because it's not been driven.... but that doesn't seem quite right.

James

blue smoke

Posted: Sun Jun 21, 2009 7:23 pm
by alfabob
Due to a lack of use it might be a seized or gummed up 'oil scraper ring' it's the one below the compression rings. In the past i have used an 'add to old oil' engine flush, like Forte.

Might be worth a try, it's a lot cheaper than a rebuild?

Posted: Sun Jun 21, 2009 7:26 pm
by whenisayjump
The type of thing a 'good run' would sort out then, if it's gummed up?

Obviously I realise this is just conjecture on your parts, but thanks for all your help!

blue smoke

Posted: Sun Jun 21, 2009 8:02 pm
by alfabob
maybe? What I have done in the past is;

Get the engine warm, add oil flush, READ tin first!

Drive for about 20 or so mls with plenty of revs to get the pressure up and the oil pumping around.

Drain the oil for as long as you can, change the fliter and add new oil.

See what happens, does not always work but i have cured many a sticking valve lifter, seized rings etc, the cheapest option by far!!

Posted: Sun Jun 21, 2009 9:19 pm
by whenisayjump
Thanks for your input. My essential dilemma is, well, rot is part of the course. It's just the blue smoke, that's a little more scary. The car is coming from people I trust, it's been to a mechanic for an MOT, and that's the feedback I've been given.

I've told them, I want to know a price with the MOT or I can't really go for it. I think that's wise.

James

Posted: Sun Jun 21, 2009 9:40 pm
by rayofleamington
I've rescued a bucket full of cars that have been off the road for a while, and NEVER come across blue smoke.
Blue smoke means oil is getting burnt. Essentially there are 3 ways it can get in the cylinder:
1) from above (valve guides - relatively easy swap for a good head, needs a socket set, torque wrench and a gasket set too)
2) from below (rings / bores, generally major rebuild, not ideal for a novice, or just buy a 2nd hand engine for an easier life)
3) with the fuel! (If it doesn't smoke when running on fresh fuel then the job's a good un, however this would only occur if there was something seriously wrong with the fuel.)

Posted: Sun Jun 21, 2009 10:13 pm
by whenisayjump
Okay. Thanks. I need to give this some thought.

James

Posted: Mon Jun 22, 2009 8:24 am
by kennatt
if you want it with an mot its going to cost you three times as much as one for rebuilding,The weldings no problem and just find a decent second hand engine and drop it in .

Posted: Mon Jun 22, 2009 8:50 am
by LouiseM
On the other hand if you want a Minor that you can use as soon as you buy it walk away and find something else. There are plenty for sale at the moment. Depends on what you're looking for really (and how much cash you have to spend). Do you want a complete project or an ongoing restoration that can be used now but improved as you go along?

Posted: Mon Jun 22, 2009 9:38 am
by whenisayjump
LouiseM wrote:On the other hand if you want a Minor that you can use as soon as you buy it walk away and find something else. There are plenty for sale at the moment. Depends on what you're looking for really (and how much cash you have to spend). Do you want a complete project or an ongoing restoration that can be used now but improved as you go along?
Yes, I think I would say the latter. I'll let you know how it transpires.

Posted: Wed Jun 24, 2009 9:29 pm
by bmcecosse
The blue smoke is the very least of the worries- - you can pick up another engine quite cheaply - what IS worrying is the comment about suspension points needing welded. THAT's the really scary point - my advice - walk away from this car - in fact, RUN.