A/c blowing warm - next steps?

[jd24689]

Hi all,

My a/c was not working so recently had it regassed. No leaks were repotted (guessing the garage would have told me). Didn't make it any better.

I'm debating whether to spend lots on a diagnosis, or to just replace the compressor myself to see if it fixes it since it will only take 30 mins or so. Was going to get a cheap used compressor for around £30, so would just be this plus the cost of the discharge/recharge.

Does this seem like a good idea or is there a good chance it will be something else?

Is there anything else I should check or any cheap sensors I should try replacing first?

The car is a 2005 c220d coupe (w203)

Thanks in advance

 

[zipdip]

Suggest you get a local car air con company to look at it,there is a mobile one in Brighton called Brigton Auto Air

 

[davymead]

Seems odd that the garage took your hard earned without telling you what was amiss. Surely they realised it was still not blowing ice cold after re-gassing and checking for leaks

 

[m80]

If it failed to blow cool at regas you 'may' be lucky in that a reset might sort it.

Best to check the pressure after an over night stand, before starting the engine. The pressure is around 3 bar.

If no pressure then a leak is conformed.

The vacuum machines are near useless for finding a leak.
Have ATS nitrogen test at 11 bar for about 20 minutes. You may find the leak is obvious at that pressure, a hole in the condensor and you may hear it hissing.

 

[Petrol Pete]

Hello and welcome . Has the a/c ever worked (ice cold) during your ownership of the car ?

The compressor is just one part of the jigsaw , condenser , heat exchanger , expansion valve , evaporator , pressure switch........ If you replace these components one by one and recharge the system each time you will spend more money than the car is worth.

Example: The pressure switch might be faulty (arguably the cheapest part) but a recharge will be required after changing it .

If there are no leaks ( I assume they have re checked it since filling ?) then testing the output from the pressure switch is next if the clutch on the pump is not engaging.

 

[W1ghty]

Also you should leave the a/c on all the time to stop the seals drying out .

 

[Rory]

The compressor is just one part of the jigsaw , condenser , heat exchanger , expansion valve , evaporator , pressure switch........ If you replace these components one by one and recharge the system each time you will spend more money than the car is worth.

Could even be a blend flap not closing fully so there's still some warm air mixing in - mine was colder on passenger side than drivers.

To be honest the a/c in my W203 was always a bit rubbish - I had the car from 5mths old and only just sold it. Multiple people looked at it and a few years ago the condensor was replaced as it was leaking due to corrosion. But it never blew properly cold.

 

[davymead]

Welcome along BTW.

 

[vijilants]

Not sure which garage you used but they should have done a before and after temp check. If the system was not working, they should have emptied out the gas and not charged you.

If I were you, first I'd go back to the garage and ask for my money back.

Your average aircon recharge service is unable to check for leaks. Places such as Kwickfit refund you if the temp is not cold or if you take the car away and the gas leaks out.

As said above, take it to a reputable aircon specialist who will diagnose the problem. If there is enough gas in the system, regardless of a leak, the compressor should engage. Leaks are usually located by injecting a dye in to the system.

You can also check for voltage at the compressor to see if it has been triggered to engage.

 

[davymead]

Not sure which garage you used but they should have done a before and after temp check. If the system was not working, they should have emptied out the gas and not charged you.

If I were you, first I'd go back to the garage and ask for my money back.

Then as said above, take it to a reputable aircon specialist who will diagnose the problem. If there is enough gas in the system, regardless of a leak, the compressor should engage. Leaks are usually located by injecting a dye in to the system.

You can also check for voltage at the compressor to see if it has been triggered to engage.

Absolutely. That’s what I’d expect, and exactly what any decent Indie would have done.

 

[Stratman]

Buy a UV torch from ebay and use it to detect any dye escaping from the system. Take a very close look at the condenser (immediately behind the front grille) and the pipes in and out of it, best viewed from under the bonnet.

 

[jd24689]

Thanks for the advice and welcomes.

I actually contacted the garage asking them if they have some kind of report from the re-gassing. They said no and that they basically just link it to the re-gass machine and press a button, that's it. This is quite a bit different to the in-depth service they make it sound like on their website!

I since contacted the local mobile air con company suggested above. They seem really helpful said they can diagnose the problem for a really good price so will do that before changing anything.

I have only had the car since October and the aircon has never really worked, so who knows how long it's been like that for.

 

[Petrol Pete]

That is really poor service . They should at LEAST test vent temperatures 'before and after' , never take your car there again and move on . you might want to name them on here so they can be avoided by local MB forum members.