W201 'smoke' from glove box?

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Rob77

MB Enthusiast
Joined
Aug 31, 2005
Messages
1,945
Location
Bolton
Car
1990 W201 2.6 Sportline; 2011 S204 C350 CDI Sport; 1978 Foale/Suzuki GS750; 1994 Aprilia Pegaso 650
A couple of weeks ago, on the M6, South to Manchester, I was stuck in a queue of traffic and what looked like smoke started to come from beneath the glove box.

It was a very hot day and my aircon isn't working. The engine temp sits normally all the time but on a hot day in town it rises a bit when stationary and it did this here too. In a situation like this, I'll sometimes put on the heater to draw away heat, though I'm not sure it does much.

Anyway, I got moving again, once the jam cleared and the car was no worse for the episode. The smoking thing lasted only a few seconds and may not have been actual smoke as there was no smell. It hasn't happened since either (or before).

Anyone know what might cause this? Might it be related to the faulty aircon? I was going to get the aircon looked at later this week.

One other thing that might be connected? Driving on a hot and rainy day in town, the heater really struggles to clear mist from the windscreen. I put that down to lack of aircon but surely I should be able to clear condensation easily without, no?

Incidentally, I put this in interior since that's where the effect was felt but appologies if it should be elsewhere.
 
Ok, I put the car into a garage to have the aircon checked for leaks and regassed - they had a special offer on.

The tech said that the system has gas in it but that it is slowly escaping into the interior, at the place I mentioned (incidentally I didn't mention all this to him).

He thinks that there is an evaporator under the glovebox and that it is faulty and leaking slowly. He explained that the gas in my system is an old type that has different connectors to the ones in use today (and since around 1995). Apparently, this gas is harmful too and he didn't want to go near it!

Does anyone know where I can get an evaporator, at a reasonable price, for fitting locally? Should I have the couplings changed over to this new type (to suit the new gas)? Or should I book it into a specialist to sort out? And if so, can anyone recommend a good (and ecconomical) specialist, either in Scotland or the North of England (I go as far down as Leeds / Manchester occasionally)

I'm obviously not keen to use the car too much until I can get all this fixed, in view of what he said, so if anyone can be of any help it would be much appreciated.

Rob
 
I would have thought that any reputable specialist ought to be able to deal with your car without any problem - if no-one else chirps in, then look on www.yell.com and see what it brings up near you in the way of vehicle air conditioning specialists.
 
Thanks Gordon. I hadn't used Yell but, sure, I don't imagine I'd have much difficulty finding an aircon specialist per se. My problem would be finding a reputable one.

Lists of companies is all well and good but what are they like, I've never heard of any, let alone had experence of them and nor do I know anyone who has.

Fixing my aircon will involve stripping out the dash and doing work that I'll never see. I don't want the work done by some poorly trained monkey who may do more harm than good. Equally, though I'm mindful that a proper repair might be costly and this is a 16 year old car.

I do want a good job doing but don't want to be stung for it so if anyone knows of a good place please let me know and I'll give it a go.
 
Right, I called a tech at random from yell.com. He operates from a van and checked out the system this morning.

He is going to convert the filling valves to the newer gas type and fill the system. There was no gas at all in it as the dryer has a big hole rusted through it (so still no idea what caused the smoke).

He is going to quote me for all of the above work and will include for a new universal dryer. An MB dryer is 76.60 + VAT and this universal one will be similar and make from steel (as original), not alloy and it'll be half the price.

I'm tempted to go for the MB unit but does it matter? Would anyone else just go for the cheaper universal part?

Also, once this work is done and the system is holding pressure, I'll be able to see if anything's actually wrong with the evaporater. I hope not as I've just had a quote from MB for the part and its £518.88 + VAT :eek: So, should it turn out I need one, I might need to consider some universal replacement for that.

Given that MB won't actually make the aircon parts anyway, presumably it doesn't matter if I use non MB spares - I'm trying to convince myself, help me out here someone??
 
Coupled with the failure to clear the windscreen i wonder if your car loses any water from the cooliing system. If so I would go for the heater matrix or pipes having a small leak and you saw steam (actually water vapour, you cant see steam) leaking into the car.
Also check the drain tubes to make sure no additional water is entering the car then being evaporated by the heater.
 
Thanks Dieselman, I'll look into that. I've still never seen the smoke / steam again but I notice a small and light oily film on the passenger footwell carpet, near the radio. Also 2 or 3 spots on the mat. Would that indicate a leak in the drain tubes?

And do you have any thoughts on the original MB v's OEM parts for the aircon? I'm leaning towards OEM, since I don't yet know where this is all going to end :(

Cheers, Rob
 
Rob77 said:
I notice a small and light oily film on the passenger footwell carpet, near the radio. Also 2 or 3 spots on the mat. Would that indicate a leak in the drain tubes?
Cheers, Rob


Below is a cut/paste of my post on another thread concerning air con........i think it is relevant to your problem.......i suspect the evaporator is leaking, the 'smoke' behind the glove box that you mentioned in your first post would have been the moment when the evaporator (or another a/c related component) failed and the pressurised refrigerent/oil was released, this would appear as 'smoke' or 'vapour' momentarily..... and i would investigate further before attempting to recharge the system ........
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http://forums.mercedesclub.org.uk/showthread.php?t=19768
Tip........Have a look at the a/c compressor, it should be completely free of any dark, 'oily' or wet patches.........if there are any leaks or seepages of refrigerent from the compressor seals or joints the refrigerent oil/gas mixture will leave tell-tale 'oily' patches at the point of escape.....the same applies to the condenser/rest of the system.
 
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Thanks, that was some useful information but, in this case, I don't think the "smoke" can have appeared at the moment of failure. The drier has such a large corroded hole in it that it must have lost all pressure quite some time ago.
 
Rob77 said:
Thanks, that was some useful information but, in this case, I don't think the "smoke" can have appeared at the moment of failure. The drier has such a large corroded hole in it that it must have lost all pressure quite some time ago.


In your second post, after the one where the 'smoke appeared, you said a tech looked at the system and said there was still gas in it?.........


Rob77 said:
The tech said that the system has gas in it but that it is slowly escaping into the interior, at the place I mentioned (incidentally I didn't mention all this to him).

He thinks that there is an evaporator under the glovebox and that it is faulty and leaking slowly
 
Yes, indeed he did say that. Clearly, he was talking through his backside though because I've since seen that it was impossible for there to have been any gas present.

As you'll see, from my posts, I've had two technicians look at my system now. That was the first one. I actually followed the second one about when he looked at it yesterday so I have a little more confidence in his findings.

Which all just goes to show why I hoped I could get a recommendation for someone to use. Strangers will often tell you just anything.
 
Good news. The (second) AC man returned today with the new drier unit, installed it, tested it, cleaned it, replaced the filler points to suit the new gas, then regassed and oiled it all.

I have aircon now :bannana:

It's holding pressure fine so the evaporator seems to be ok. He did say that since it hadn't been used in a while, it was possible a leak may develop later. I'll watch out for that.

Still no idea what caused the oil droplets though. It does seem something occasionally drips oil from somewhere behind the dash. Its not a worrying amount or anything so maybe I'll just wait and get it looked at when it gets its service.
 

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