BMW 3 series 320D ac blowing hot air

Question

It has recently been really hot and to my surprise on the hottest day of the year my ac was not working.

I took it to halfords to get the ac recharged however when they attached the pressure gauge it did not register anything, obviously with the car running and ac turned to max.

I checked for the compressor and it does kick in as you can hear the engine working harder.

Is this something like a block or a leak? Or is it that I havent recharged it for the past year (and I have no idea when the last time the person before me recharged it) might it be that its never charged?

Is there any other checks I can do? Or do I have to take it to a garage or BMW?

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Answers

Compressor kick in as the engine started reving and shaking... Like something in the back of the engine started...

I'll turn on and check along the line...

I was also thinking of taking it for a service in case there are a lot of bits in the pipes and it is blocked

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Took it to the garage.. compressor doesn't appear to be moving. However there is literally nothing in terms of gas in the system at all!! So I will take it to halfords to fill it up .. the guy said the person probably didn't screw it in and if there is nothing inside then how would it create pressure? Is this true?

Answer 1

Did you see the compressor kick in? If not, I'm thinking your car doesn't have any refrigerant in it. If they put the gauges on the system and it didn't register anything, that's a pretty good sign it doesn't have any refrigerant in the system.

If your car has completely lost its charge, this means there has been a catastrophic failure somewhere in the system ... it has lost its integrity and no longer is holding refrigerant. Unless you are an A/C mechanic, this is more than likely something which will need to go to the shop to fix.

If the compressor did actually kick in, then whomever put the gauges on the A/C system to check it didn't do a very good job of checking. There is no way it will kick in without refrigerant in the system. You can, however do a very easy check by touching the A/C lines right at the firewall (or as close as you can get to the firewall) as they go into and out of the body of the car. Feel the lines and see if one is cold and one is hot (or warm since you aren't getting any benefit from the cooling). If so, you're moving refrigerant and something is wrong inside the car, like there may be an issue with the hot/cold blend door not opening so the cold would be present in the cabin. You could possible dig into the dash of the car and replace this yourself, but it is a chore in most cases.