Air Con Issues

[dry run]

Hi all,

Air-con is malfunctioning and I'm absolutely stumped as to what is going on.

All the switches work/light up, fan increases and descreases in speed, turn the heat up and it gets hot, turn the heat down and drivers side pumps ambient (non cooled) air, but the pasengers side still blows hot (not full heat, but heated). Air con off or on makes no difference, but clearly the car is not artificially cooling the air.

Any ideas? I'm guessing a re-gas to start, but it seems a little more complicated than that given the temperature issues.

If you have ideas, please feel free to ask questions, as I didn't want to create a long over complicated post.

TIA

 

[mattkh]

What year car.?

 

[dry run]

2015

"Annoyingly", when I drove to work this morning, it appears to be functioning correctly - which I'm pleased about, but doesn't bode well for the future

So, would still welcome any comments on what could have been the cause.

 

[mioba]

get it diagnosed pal, star will id the culprit.

 

[dry run]

get it diagnosed pal, star will id the culprit.

Does STAR diags cover the air con?

 

[Blobcat]

Sounds like a jammed duo-valve - they can stick leading to temp imbalance issues as well as always hot or always cold

 

[dry run]

Booked in for re-gas on Tuesday, I'll ask them about the duo-valve. Is it easy to get to?

 

[Wighty]

May well have logged a fault code on the car ? At 6 years old it’s due a regas anyway

 

[Botus]

Sounds like a jammed duo-valve - they can stick leading to temp imbalance issues as well as always hot or always cold

my car has rear AC control, last summer the right rear jammed on full heat and tried to melt the car.... the rear controls bring a crazy valve behind the right front wheel many call the duo valve, but whilst some are cheap mine is 500 quid. It has these odd poppet valves in it and aftermarket people make repair kits for... but allegedly by the wipers is another two £50 black plastic mixing units that also fail

 

[Botus]

in comparison to mine this system doesn't look much more complex than a lit match

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nemigaparts.com

part 150 under hot water lines ?

 

[th3h1ghlander]

Does STAR diags cover the air con?

Diags do cover aircon (to some extent depending on model and year). Just as an example, a diag done on my 2002 w203 activates the actuators on the venting for the climate control zones and does even identify that one of the actuators is blocked or sticking resulting in sub-optimal or incorrect operation in a specific zone.

Recommend a diag is done to help pinpoint any issues.


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[davemercedes]

I use a local garage for my regular service work. Roughly every couple of years it’s noticeable that the aircon isn’t up to the job. They check the gas levels and top it up (Labour = £0 but he charges for the gas etc) then that’s it for the next couple of years. I run the car with air on on all the time and just adjust the temperature as necessary. I had a check done on a special offer 7 or 8 years ago and ATS said it was all in order.

But funnily enough in HOT weather I’ve never thought it to be quite adequate.

 

[mioba]

Does STAR diags cover the air con?

Yes, I diag will identify parts of the circuit that may have failed (compressors, valves, relays, switches, the control unit) and the gas level.

A run of the mill place gassing your car will only gas the car and the most they can do it terms of diags will be find a leak.

Hence the need to get it properly diagnosed.

 

[dry run]

Thanks guys for the replies. Now that we have actually had some hot weather, the air con issue has become apparent (funny though that car never steamed up during the rain we had recently - which leads me to believe the air intake has been "Air conned").

Hopefully, the re-gas will prove to be the panacea to my problems, but if not it will have to go on STAR for a diagnosis (if any shown).

I'll update as revealed

 

[th3h1ghlander]

But funnily enough in HOT weather I’ve never thought it to be quite adequate.

When I got my w203 second-hand, with an original Mercedes A/C compressor pump, it was icy cold within seconds and was most certainly cold enough on the host test of UK days ... however ... 6 months after I got the car on a hot autumn day all of a sudden the cold air stopped mid-use. I suspected need to gas but took it to an Indie to check, did a star diag but he concluded that it was the pump and that I should take it to an A/C specialist to get checked/replaced/re-gassed.

I did this, took it to a place near Staples Corner on the A406, they confirmed that it was the pump and told me replacement pump, leak check and re-gassing was £325 all in. Picked it up later that day and it has been working fine ever since however I will say that it is nowhere near as cold as it was originally and it does take longer to get cold as well. I suspect the pump is not OEM and would have been whatever re-manufactured part they had laying around and is not as good as the original...but it didn’t break the bank and is 85% as good as the original and still working 5 years later.


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[dry run]

Just got the car back from a £50 air-con service and re-gas From ATS Europmaster in Portsmouth.

Pleased to report that everything is working like it should - very cold air available on-tap, auto function working, all zones working fine. Just need the good weather to hold so I can enjoy it

Thanks for all the replies and help.

 

[mioba]

Glad you are sorted OP. If it still works after a week you are sorted. Keep it on all the time otherwise seals dry and the pump siezes.

 

[dry run]

Glad you are sorted OP. If it still works after a week you are sorted. Keep it on all the time otherwise seals dry and the pump siezes.

Apparently, they have a very clever machine that checks the whole AC system for faults (including leaks). Mine passed with just a re-gas so I'm hopeful for the future, Have always run my cars with the AC on, but maybe the previous owner didn't?

Thanks for your input!

 

[Wighty]

Apparently, they have a very clever machine that checks the whole AC system for faults (including leaks). Mine passed with just a re-gas so I'm hopeful for the future, Have always run my cars with the AC on, but maybe the previous owner didn't?

Thanks for your input!

Onward to the next fault buddy

 

[peterws1957]

Onward to the next fault buddy

Nothing like being optimistic