AirCon - not cold, but compressor working?

[Crowz]

Only issue I have with replacing the valve is that for me it didn't help any and the fact I was out the money for Freon and the valve.

Well that and it was a pain to fool with from under the car.

Factoring in the cost :

$40 crappy snap ring pliers set
$15 Freon
$15 valve
Gas to go get Freon and valve.

So $70 in parts and the royal pain of fooling with the compress from under the car.

New compressor which I had to buy anyways because the valve didn't fix it was $110 or so.

So a bit more and you have a new compressor and piece of mind.

Its just not worth it to fool with the valve. If the valves toast then the compressor isn't that far off. New compressor has new valve.

[upallnight]

Originally Posted by Crowz

Only issue I have with replacing the valve is that for me it didn't help any and the fact I was out the money for Freon and the valve.

Well that and it was a pain to fool with from under the car.

Factoring in the cost :

$40 crappy snap ring pliers set
$15 Freon
$15 valve
Gas to go get Freon and valve.

So $70 in parts and the royal pain of fooling with the compress from under the car.

New compressor which I had to buy anyways because the valve didn't fix it was $110 or so.

So a bit more and you have a new compressor and piece of mind.

Its just not worth it to fool with the valve. If the valves toast then the compressor isn't that far off. New compressor has new valve.

Most compressors bought on-line are either refurbish or made in China.

[andrewwynn]

How great is that $15 valve. Great price on compressor. Before buying x5 I searched price of ac compressor and I thought was maybe $250. So much for the myth of BMW = expensive parts.


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[Crowz]

For me the $15 valve wasn't worth the gas it took to go get it. Did nothing to restore the compressor on mine.

This I the compressor I went with. Works awesome and is showing $119 right now.

https://www.ebay.com/itm/New-CO-1083...-/222490065603

[andrewwynn]

That is awesome. I check my hi/low on both x5 a couple times a year to make sure the compressor seals are holding.


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[more_fasterer]

Thanks for the advice guys. We can't buy R134a over the counter here in NZ for environmental reasons, so I'm gonna be stuck with taking the car to a service agent to get the aircon working properly.

With that said, I went to a friendly auto electrician today (to talk about an issue with the 335i... sigh, BMW life) and it turned out that he had a set of gauges. The low side was sitting at 26psi and high was at 220psi, so a bit low but not out of range. Oddly, he added a bit of gas into it and now it generates a modicum of cold air, unless the engine is idling - in which case no cooling occurs.

Originally Posted by upallnight

Do you have the variable valve compressor? Have you hooked up a set of gauges to the low and high side of the system? If not hook up a set of gauges and tell us what the low side and high side readings are.

Yes, it has a variable compressor.

Originally Posted by upallnight

Don't have a set of gauges or don't know how to hook up a set of gauges, pay for my round trip ticket to NZ and I'll bring my tool and I'll tell you what the pressures are. If that is too expensive for you, take it to an AC shop and let them tell you what the pressures are. If that is too expensive, just lower the windows and drive around with natural air conditioning.

I feel like you could've presented those options in a slightly different order

Originally Posted by Crowz

Only issue I have with replacing the valve is that for me it didn't help any and the fact I was out the money for Freon and the valve.

Well that and it was a pain to fool with from under the car.

Factoring in the cost :

$40 crappy snap ring pliers set
$15 Freon
$15 valve
Gas to go get Freon and valve.

So $70 in parts and the royal pain of fooling with the compress from under the car.

New compressor which I had to buy anyways because the valve didn't fix it was $110 or so.

So a bit more and you have a new compressor and piece of mind.

Its just not worth it to fool with the valve. If the valves toast then the compressor isn't that far off. New compressor has new valve.

Good feedback. Thanks for the link to your useful write-up, too. I'm gonna organise to have the car looked at by an aircon specialist, cos I don't really have much option. Which kinda grates, as I have DIY'd everything else on this car (including changing the trans solenoids). But it sounds like I can expect a "you need a new compressor" diagnosis.


Cheers guys

[upallnight]

Originally Posted by more_fasterer

Thanks for the advice guys. We can't buy R134a over the counter here in NZ for environmental reasons, so I'm gonna be stuck with taking the car to a service agent to get the aircon working properly.

With that said, I went to a friendly auto electrician today (to talk about an issue with the 335i... sigh, BMW life) and it turned out that he had a set of gauges. The low side was sitting at 26psi and high was at 220psi, so a bit low but not out of range. Oddly, he added a bit of gas into it and now it generates a modicum of cold air, unless the engine is idling - in which case no cooling occurs.



Yes, it has a variable compressor.



I feel like you could've presented those options in a slightly different order




Good feedback. Thanks for the link to your useful write-up, too. I'm gonna organise to have the car looked at by an aircon specialist, cos I don't really have much option. Which kinda grates, as I have DIY'd everything else on this car (including changing the trans solenoids). But it sounds like I can expect a "you need a new compressor" diagnosis.


Cheers guys

The low side appears to be lower then the design parameter. What was the ambient air temperature when these readings were taken?

It could also be the expansion valve that is attached to the evaporator inside the car. You will need to recover the refrigerant before you can replace it.

GL

[Crowz]

If your getting that kind of low side reading then the compressor should be fine. When they mess up from the valve it doesn't usually get very low on the low side.

Best way I have found to diagnose the valve is to go on a loooong drive with the a/c on. If it starts cooling eventually and works great when it finally does go to cooling its a bad compressor for sure.

If it never goes to cooling no matter what time wise then its not very likely to be the variable compressor. Also adding Freon will not effect cooling at all. If you add Freon and it cools its not the valve.

[upallnight]

Originally Posted by Crowz

If your getting that kind of low side reading then the compressor should be fine. When they mess up from the valve it doesn't usually get very low on the low side.

Best way I have found to diagnose the valve is to go on a loooong drive with the a/c on. If it starts cooling eventually and works great when it finally does go to cooling its a bad compressor for sure.

If it never goes to cooling no matter what time wise then its not very likely to be the variable compressor. Also adding Freon will not effect cooling at all. If you add Freon and it cools its not the valve.

Automotive refrigeration system are designed so that the evaporator core does not get below 32 F. Why, when our refrigerator at home can get to a temp below 32F. Because unlike a refrigerator that has a frost free heating element design into it to eliminate ice build up on the evaporator, the evaporator in an automobile does not have this feature. And with the hot humid air that is drawn into the car, a lot of humidity is condensing on the evaporator. If the evaporator core was allowed to get below 32F, the water would freeze and block the incoming air from passing through the evaporator. This will prevent the air from cooling down so now you have warm air going around the evaporator instead of through it. When this happens you don't have cold air coming out of the vent.

A low side pressure also determine the coldness of the evaporator core. The lower the low side pressure the colder the evaporator can get. This is why the design low side pressure is usually around 34 - 40 PSI.

[andrewwynn]

I can look back I usually take photos I might have the exact numbers when I redid my AC but the numbers are much higher something like 45 low and 240 High. I didn't see the numbers after adding the freon. It's funny talking about fixing AC because of course it's about 10 days from winter here in Wisconsin


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