Intermittent smoking

[Firkie]

Hi, I've got a strange problem with my 1.9 water-cooled T25. There is intermittent smoking on start up, sometimes it is very bad! Initially having inspected the air box I thought it was oil vapour collecting from the breather and entering the carb. This seemed to make sense, so I cleaned the breather tower and pipe, but this didn't last long before the problem returned! My next idea was to cap the air box and allow the vapour to escape to the atmosphere ( not an ideal solution). I thought I'd isolated the issue (heavy breathing , maybe exhaust gases pressurising oil ....head gasket?). But having starting the van and getting a good start no smoking and choke engaged two or three times, I started it today and it smoked badly after a few seconds on start up after struggling to start coughing stuttering and cutting out????
I'm lost?? If the valve seals are shot, surely it would smoke every time it was started after standing for a few days.
Any help, advice would be greatly appreciated

[meggles]

Are you getting excessive smoke when it's been stood for a while, but not when it hasn't been stood. Answer to this could give a clue.

[Firkie]

To be honest, I start it maybe every third day which may include a run up the road. It doesn't seem to have a pattern, not one I've noticed. I would understand the smoke if it only smoked after standing a while. But it doesn't want to run on the occasions it smokes, I've got to hold the revs or it will die. But to start it I always pump the accelerator a few times and on the occasions it doesn't smoke it will start and run on choke without touching the accelerator ??? When i take it down the road there is no smoke even if I push it a bit ( I've had my dad follow me for that reason)

[meggles]

To be honest, I start it maybe every third day which may include a run up the road. It doesn't seem to have a pattern, not one I've noticed. I would understand the smoke if it only smoked after standing a while. But it doesn't want to run on the occasions it smokes, I've got to hold the revs or it will die. But to start it I always pump the accelerator a few times and on the occasions it doesn't smoke it will start and run on choke without touching the accelerator ??? When i take it down the road there is no smoke even if I push it a bit ( I've had my dad follow me for that reason)

Thinking excessive oil draining down the valve guides and therefore plugs can't spark due to oil fouling. Sorry if it's not much help. Have you looked at plugs to see if they are oiling up? Have you tried removing air box and starting up? Thereby removing the chance of it being oil drawing through the top of the carb? I'm not an expert but I reckon it's a possibility.

[Firkie]

I haven't looked at the plugs, although when I got the van Christmas time I did replace plugs, leads, oil and filters and the plugs I took out were old but clean . I do appreciate you replying and offering advice

[meggles]

I haven't looked at the plugs, although when I got the van Christmas time I did replace plugs, leads, oil and filters and the plugs I took out were old but clean . I do appreciate you replying and offering advice

No problem. This is what the forum is all about. My son is a brilliant mechanic, just walked into the room. If he can offer some advice I'll post again.

[meggles]

He suggests maybe another breather somewhere which is blocked... but he isn't 100% with these engines. Sorry if it doesn't help.

[Firkie]

Maybe someone else could confirm this and steer me in the right direction to sort it out?
I'm on a 04.50hrs start in the morning , my bed is calling me
Look forward to hearing any more advice

[NicBeeee]

But to start it I always pump the accelerator a few times and on the occasions it doesn't smoke it will start and run on choke without touching the accelerator ???

Hi
Just to rule it out, are you following the correct starting procedure, press accelerator fully down, lift of foot, start engine without touching accelerator, should tick over at 2000 revs to start with.

[kevtherev]

what colour is the smoke?
Black ,blue or pale blue

[Firkie]

The smoke is blue, and stinks of oil.
I wouldn't think pumping the accelerator a couple of times would cause smoking, it's a method I found works for my van. I've tried different methods, but the smoking isn't every time.
I'm thinking its valve stem seals like suggested. I've tried to source the parts just, but can only find the diesel seals? Tried vw heritage and just campers

[Firkie]

Just had thought.... After the oil change I put a tin of wynns in? Surely this wouldn't cause any trouble?
I've used the stuff for years and always felt it was a good additive

[kevtherev]

the blue smoke is oil
So I think you need a compression check.
DG engines don't have valve stem seals
I would think your problem is worn valve guides or piston rings
The poor starting, running may be coincidence but a compression check will tell
Though it does suggest a choke issue if you have to stomp on the accelerator to get it to start



As an aside..
What does the additive claim to do...that your oil doesn't?

[Firkie]

Would worn piston rings cause smoking just on cold start?
Do you know if the valve guide replacement is easy enough to do?

[kevtherev]

maybe

and.. I have never had to so I can't coment... 134,000 miles still ok

What does the additive do?