E53 air con compressor not switching ON

[X5Sport]

About the only thing you haven’t changed is the actual controller in the centre console.  Is it working correctly?

If the green led next to the ‘snowflake’ symbol lights up, can you cycle the temperature across the complete range?  Something like 16°C to 35°C? 

At its lowest setting the blowers should all go to full speed.  It isn’t unknown for the actual controller to fail even though all of the lights come on, the temperature control doesn’t work.  It’s a non-repairable module.

I’m assuming from your last comment that the pressure is now holding?

[kanewesley]

Yes X5Sport, the pressure is now holding and I believe the centre console is Ok.

All lights lighting up as they should, temperature changing as selected, blower fan changing speed to suit.

I even tested the output from that controller PCB to the compressor and that is switching on correctly, as it should, so it seems that bit is ok too.

Just no cold air !

I wondered if perhaps the sensors monitoring the gas lines aren't responding as they should, but the fact that the controller is switching on an output to the compressor rules that out I believe.

[X5Sport]

There must be a thermometer somewhere that also drives this.  Do the pipes to/from the compressor itself get cold?

I’m kind of wondering whether there is an issue with the ac radiator matrix?  If the system lost its gas, did the rad get filled with crud.  There is a dryer in the system somewhere to keep water under control.  If the internal rad flow is down, or even the air ducts passing it are constricted then perhaps the air mixing isn’t happening and although the system is getting cold, the air flow is too low into the cabin.

You could try (carefully) poking a barbecue thermometer into the ducts to see what the air temp actually falls to.  I use one of these...

https://www.amazon.co.uk/gp/product/B01 ... UTF8&psc=1

......for monitoring the air temperature in the enclosure when 3D printing, or when annealing the output in the oven.

Other out of the box thoughts are whether the compressor is actually running properly.  The clutch works but is the compressor actually doing anything?  As the system lost its gas I’m wondering (aloud) whether a seal has given up and the coolant is just not getting compressed.  The condenser radiator at the front of the car should be getting warm too if my physics is working, due to compressed gas getting hot.  Airflow over the condenser cools it down so if my theory holds, the rad should warm up if no airflow is there (such as would happen on a stationary car).

As you rightly say, it’s only a bl@@dy fridge!

[kanewesley]

No Bud....the pipes to and from compressor not getting cold.

TBH I dont think the BMW guy I took it to is up to the mark. I think He's stringing me along.
I don't think he understands the process enough to collect the right evidence and diagnose the problem.

I think I may wait while next summer now, cut my losses and accept I've wasted money. I need to stop throwing good money after bad at it and start again with a fresh, knowledgeable pair of eyes next year.

I've spent a fortune and am no further forward than I was 4 months ago.

I've come to this conclusion X5Sport after reading your last contribution. I think if the guy I trusted had your train of thought, It would have been sorted a long time ago.

Oh well....you live and learn.

Hindsight is a great thing !

[kanewesley]

One more thing X5....since He's brought my car back, I have a "fuel inject fault" on it which he claims to know nothing about !!!

[X5Sport]

If the pipes aren’t getting cold that ‘suggests’ a compressor internal fault.  Need someone else with one of these cars to confirm what they get on their pipes too.

Injection issue could be disturbed wiring underneath the engine cover, or disturbed the fuel rail?  Someone close by with Carly may be able to pin down the actual code - if you don’t have it yourself.

[kanewesley]

I wish you lived next door to me ! :-[!!!

Whats Carly?

[henrym3]

I’m in Ireland atm but will probe the compressor pipes when I get home on Tuesday. I do know that the compressor outlet gets seriously hot and the return from the evaporator much cooler. Will give more accurate temperatures on Tuesday. But cold pipes suggest the compressor isn’t compressing

[X5Sport]

[quote="kanewesley"]
Whats Carly?
[/quote]

One of these.....

https://www.mycarly.com/product/bmw-app/

[kanewesley]

Never heard f it...is it new???

Will it work on a windows phone because not much does !

Is it free?

Where do I get a lead from to connect to car?

[X5Sport]

1.  Not really, several years old but constantly updated.

2.  No.  Android or iOS only.

3.  No - dedicated dongle is €69 and the App is £59 I think.  ‘Lite’ version of the App is free, but limited unless you pay.

4.  You don’t need a lead as it is all wireless.

I have the iOS version which uses WiFi (Android uses Bluetooth).  The dongle plugs into the OBD2 port and a tablet connects to it.  No other suppliers dongle works.

[henrym3]

Slightly confused with the temp readings on the pipes to/from compressor. BTW when checking the compressor clutch was cutting in and out on a regular basis. Inlet to compressor 30/32c and outlet to condenser 40/46c

[X5Sport]

Compressor output side will be higher as the compression process generates heat if my physics is correct. 

Refrigerant leaves the compressor as a high temp/high pressure gas. 
The Condenser will cool that down again enough to form a high pressure liquid refrigerant which then goes through the drier. 
Then onto the expansion valve to become a low pressure liquid. 
Then into the evaporator (this is where it meets fresh air flowing through the evaporator fins and pulls heat out of it) where it vaporises and expands further to become a low temperature gas again to go to the compressor.

Those temps look about right to me 

If the temps are the same both sides then it could be a stuck open expansion valve (so no pressure differential is maintained), bad compressor, blocked/bad evaporator, defective drier, blocked condenser, blocked pipes somewhere.

BMW can check the E53 with pressure gauges either side of the compressor as it is unregulated on these cars.  Later models are regulated so this technique doesn’t work.  If they can do it then any half decent AC specialist should be able to as well.

The TIS tells techies what to do ... not a diyable job

https://www.newtis.info/tisv2/a/en/e53- ... k/GbGkqA9N

[X5-D-Sport]

There is another option....

It may be that EVERY thing electronic is working properly.

I have an electro-magnet failure at the AC pump.

It is rare the pump itself fails if regularly powered up, but the coil that energises the magnet & works the clutch is a failure point.

Normally, you have a 4 hr job & replace the whole pump, as BMW do not sell the coil as a sub part...
However, I found a compatible coil that WILL FIT, & you can install it easily.

A small chunk of fan shroud needs to be removed, the belt tensioner levered to release the belt, & the clutch assy removed from the front of the pump. You will need long reach circlip pliers & work from under the vehicle with the undertray removed.

To test the solenoid (before you waste money), get under the vehicle & put a meter across the solenoid connections after disconnecting the device.... generally they fail open circuit.

I have a few solenoids ready to fit @ £85 each.

[kanewesley]

:-[
OK...so how embarassing.
Aircon still not working but now I know why it couldnt be mended.
The BMW tosser I took it to was ripping me off. I kept paying him cash in hand and he kept coming up with all sorts of finds and excuses till I'd had enough.
Final straw came when the last 2 days of him having car he disappeared with it for 2 days and kept lying to me.
He took £50 her, £100 there,.....but he seemed so believable.
Turns out he was and ex jailbird, a conman who took me for a ride to the tune of £700 in all.....all I got for that was an MOT certificate and lie after lie......Can't believe I was taken in but he seemed so gen.
Still no aircon if anyone knows where I can take it Doncaster area... :-[