smoke in the cab....

[NOOG_monkey_II]

Hi all, can I pick the collective knowledge please?
A couple of times now I've got smoke in the cab, particularly noticeable when I stop at traffic lights, it is coming from the air vents and the floor/bottom of the dash. I'm driving a 1981 air-cooled.
I'm presuming this is oil burning (or something burning?) as opposed to exhaust fumes? Im also assuming this has something to do with the heat exchangers in some way? This is where my knowledge peters out a bit as I thought my heat exchangers were discontented after a problem last year with constant heat and oil smells in the cab (no smoke) and taking it to a garage recommended on this forum. Certainly my heater controls are not connected and have no action on heat/air. There is not a vast amount of heat coming out either as I used to have previous to the fix.

Now I took the van in for a service a couple of weeks ago (again to the well known local Brighton garage from this forum) and mentioned the smoke issue. When I picked it up he said he had fixed it, and that it was oil on something - my first drive of 45mins in it though and it was doing exactly the same, so If I go back I want to be better armed with what it might be? Can I not completely cut off the source of the air coming back up into thw cab somehow? Also I had a look under the nearside rear arch and can see an open pipe which I think used to be connected to the heat exchanger, picture attached. Could this be a cause? Is there something else other than the heat exchangers it could be?

ta muchly!

[NOOG_monkey_II]

Im going to answer myself.... Ive just got under the van and had a proper poke around after reading another thread on here. That opening is from the nearside heat exchanger so I assume smoke can deffo be sucked back up into the cab here correct? The other end of the pipe is just hanging out of sight. On the off side the connection seems intact but on the underside of the heat exchanger I've noticed fresh oil for the first time! doh. Now just to find from whence it came. Cant say I'm too happy that the garage has left it like this after I've raised the issue with them twice and given them a fair chuck of cash the last two years - not naming names, but can anyone recommend any other Brighton based "specialists" I can try? Where the heat exchangers join the exhaust they are very rusty as well - would there be an issue with exhaust fumes getting in?

Thanks!

[82JEW75]

Sounds like your heat exchangers are connected on one side and disconnected on the other?

(The one pictured is disconnected)

If so, disconnect the other side, this will "fix" the smoke problem, but you really want to look at the source, there shouldn't be any oil leaking anywhere.

Treat the cause, not the symptoms...

[NOOG_monkey_II]

Thanks, so there is no issue in disconnecting the two completely? do I need to block up the open pipe there? Or can I just remove the pipes back to the cab completely? Im aware fumes might be getting sucked back up that pipe.

Needless to say I shall be trying to get the leak sorted (its not huge, today is the first day I've noticed any on the road where Im parked), but I do need to drive it next weekend so might not be able to book it in anywhere before then.

cheers!

[82JEW75]

Thanks, so there is no issue in disconnecting the two completely? do I need to block up the open pipe there? Or can I just remove the pipes back to the cab completely? Im aware fumes might be getting sucked back up that pipe.

Needless to say I shall be trying to get the leak sorted (its not huge, today is the first day I've noticed any on the road where Im parked), but I do need to drive it next weekend so might not be able to book it in anywhere before then.

cheers!

It's not a bad idea to block off the ends of the pipes you disconnected, just to keep them clean really. Not much point trying to block off the ends of the heat exchangers, if the flaps are open, anything you put on there will just get blown off.

You won't hurt anything running with those pipes disconnected, though obviously you'll have no heating.

I'd start planning for the engine to come out, you haven't mentioned what it is (CT? CU?) but it might not be a bad idea to start looking for cheap exhaust parts if you think your exhaust is on it's last legs, they can be hard to find, particularly CT, so best to collect all the bits needed in advance.

Good excuse to treat the engine to an overhaul anyway

[NOOG_monkey_II]

It's not a bad idea to block off the ends of the pipes you disconnected, just to keep them clean really. Not much point trying to block off the ends of the heat exchangers, if the flaps are open, anything you put on there will just get blown off.

You won't hurt anything running with those pipes disconnected, though obviously you'll have no heating.

I'd start planning for the engine to come out, you haven't mentioned what it is (CT? CU?) but it might not be a bad idea to start looking for cheap exhaust parts if you think your exhaust is on it's last legs, they can be hard to find, particularly CT, so best to collect all the bits needed in advance.

Good excuse to treat the engine to an overhaul anyway

Its a new-ish engine, replacement 9 years ago, 2 litre vega CU. approx 15k on it.