C200 Elegance-Air-Conditioning Overflow or a Problem?
 

I live in the UK so drive a right hand 1996 C200 Elegance which I bought last June.

I recently had the head gasket replaced (the radiator was also replaced a month before) both fortunately under a warranty insurance. Yesterday, after returning from a trip, I noticed water dripping under the car. The position was roughly to the rear of the engine and slightly to the left when looking from the front. Looking from the side it was inline with the Elegance badge.

I've been told that this is almost certainly the air-conditioning overflow(?) but I haven't been
able to clarify exactly where that is situated so can't be sure the water I'm seeing is
collecting in the right place to be from the AC unit.

My concern is that whilst the radiator was being replaced by my local mechanic, he pointed out there was also evidence of the head gasket leaking from a position roughly to the rear of the engine and on the left looking from the front. I believe there is a drain cock at that position which he initially thought might be weeping but when he took off the manifold he saw staining confirming the gasket was faulty.

During this time I'd noticed a similar pool of water under the car at odd times, in more or less the same position as now. I assumed the water was from the faulty gasket as I was told the gasket leak would only show when the engine was cooling and the position seemed right.

The head gasket repair was done by the the dealer from whom I bought the car, who is a MB specialist but not main dealer. I have spoken to him and he assures me that everything is OK and not to worry, but!

I also spoke to my own mechanic, who is not MB, but who detected the head gasket problem. He told me to run the car for a time and see if the header tank loses a significant amount of water, although as the gasket was only replaced a couple of weeks ago I was told there may still be some air in the system so some topping could be needed and wouldn't be unusual.

Neither the dealer nor my own mechanic can tell me exactly where the AC overflow(?) is situated on the C Class so I can't judge if the water dripping is in the right place for it to come from the AC. My own mechanic did however say that in his experience most AC overflows(?) are situated more or less under where your feet rest on the pedals (this of course would only be for RH drive vehicles).

The dripping was quite regular shortly after I parked the car but had begun to slow down within a couple of hours, all of which I hope points to the AC. I was told to place a clean dish under the car next time to collect any water and to taste it to see if it has anti-freeze, which I'm told would have a sweet taste. Don't much relish that idea so wondered if there was any other way to determine if the water contained anti-freeze or not, perhaps a litmus paper test or similar.

Can you help please?

The AC system removes moisture from the air. It has to go somewhere. When you stop, you'll see it dripping.

Normal. Check if it's water, if so, you're fine.

Hi blackmercedes

Thanks for the reply.

Appreciate the AC has to drain but it was the similarity of where the water was laying with what I saw before the head gasket replacement that started to get me paranoid.

I've since come across some other info saying that on a LH drive C Class the AC drains on the passenger side of the firewall, just about in line with the pedals, so on a RH drive that would put it just where the water is laying which is encouraging.

Checked under the car today and it's dry so it does look like the AC but will check again after I get back from the weekend and put a clean dish under to catch the water so I can check it's "clean".