Air conditioning cylcling

[m3f_mofood_f82b2cec49]

Looking for some air expertise here. My A/C compressor has been cylcling quite frequently (maybe once a minute or more). City/Highway doesn't seem to matter. I keep the temp set at the coldest setting, both driver and passender. It seems to blow cold when the compressor is on, and gains just a little temp when the compressor is shutting off. Does this consistently, as long as the a/c is on.



Is this a typical low r134a pressure? I know low pressure level will cause the compressor to not kick on at all if low enough. I've heard the expansion valve can be faulty also, and may cause this..



Any help is appreciated in advance.

Thx

[m3f_Mr ///M3_1448fff35e]

Looking for some air expertise here. My A/C compressor has been cylcling quite frequently (maybe once a minute or more). City/Highway doesn't seem to matter. I keep the temp set at the coldest setting, both driver and passender. It seems to blow cold when the compressor is on, and gains just a little temp when the compressor is shutting off. Does this consistently, as long as the a/c is on.



Is this a typical low r134a pressure? I know low pressure level will cause the compressor to not kick on at all if low enough. I've heard the expansion valve can be faulty also, and may cause this..



Any help is appreciated in advance.

Thx



It's normal for a compressor to cycle, but in your case a little too frequent. This is what the trade call, short cycling.

Did you measure the air off temp when the compressor is running and just before it cuts out ? What I mean by this is the temp of the air coming from one of your vents. For R134a you should be reading between 5 and 7 degrees C. I have seen it fall a tad under 5 degrees only on mild days. The hotter the ambient temp, the harder the system works.

Also, if your TX valve is faulty, you will see it ice up on the out going side to your evaporator. This will indicate either a blockage or a malfunctioning needle and seat (bellows).

Another thing you could have checked out is the temp sensor, I kind of doubt this would be an issue, but then again it pays to check anyway.

Hope that helps:thumbsup2:

[m3f_mofood_f82b2cec49]

Good info :thumbsup2:

I'll look for the icing, and check air temps.

Then i'll have the pressures checked.

Thanks

[m3f_JPoland_e17b491a3d]

It is most likely low refrigerant level. It is extremely common for car a/c units to slowly leak over time. Your simplist and likely cheapest first attempt is to add 134a. I would almost put money on that being the problem.

[m3f_Mr ///M3_1448fff35e]

Forgot to add, you can try bridging out your low pressure switch to enable the compressor to keep running, this will help you narrow it down between a shortage of refrigerant or in fact a faulty TX valve. If it has a refrigerant leak, you can get yourself a spray bottle and mix some dishwashing liquid and water then spray all your hose connections and where you see bubbles, that's your point of leakage, then again you could have more than one. Over time the O rings at your connections will tend to dry out if your A/C isn't used on a regular basis and refrigerant can slowly leak out. Oil that present in the system will migrate around and this in turn helps lubricate the O rings.

Hope it works out for you.

[m3f_mofood_f82b2cec49]

Forgot to add, you can try bridging out your low pressure switch to enable the compressor to keep running, this will help you narrow it down between a shortage of refrigerant or in fact a faulty TX valve. .



Would this damage the compressor if in fact LP side is low? Or are you saying check temps with the switch bridged, if it get's colder, it's a switch? Compressor running (continuous)-> colder -> bad switch?

or: Compressor running (continuous) -> no colder -> low refrigerant?



Good input all

Thanks

[m3f_Porschetec_b3046e5dde]

how cold does it blow?

[m3f_MyM3416_7ede772d78]

Usually a compressor cycles like that due to a low freon level. Get your level/pressures checked and go from there.



how cold does it blow?



what is your last name?

[m3f_kwipp_f8cf9d8d93]

Usually a compressor cycles like that due to a low freon level. Get your level/pressures checked and go from there.







what is your last name?



Do you have a link to some pics of your car? That color looks awesome.

[m3f_Mr ///M3_1448fff35e]

Would this damage the compressor if in fact LP side is low? Or are you saying check temps with the switch bridged, if it get's colder, it's a switch? Compressor running (continuous)-> colder -> bad switch?

or: Compressor running (continuous) -> no colder -> low refrigerant?



Good input all

Thanks



Yes it can, if your system is critically low then your compressor will run too hot and the lack of lubrication will damage it.



There are two many scenarios to mention and you'll wind up getting confused.

Unless you have a set of guages and some refrigeration experience you will be chasing your tail.

If you know someone close by with a set of guages, visit this link and go from there.



http://www.aa1car.com/library/ac98.htm



Unfortunately, I'm on the other side of the world and would help out if I could get there in person. Good luck and let us know how you go :thumbsup2:

[m3f_MyM3416_7ede772d78]

Do you have a link to some pics of your car? That color looks awesome.



Thanks. I'll have to look and see. I posted some a little while back...I'll see if I can locate them.

[m3f_mofood_f82b2cec49]

I do have access to gauges, just never really messed too much with a/c. I'm pretty handy with a wrench, though.



I haven't checked the temp yet, as I was gone all weekend, and now preparing for events next weekend...never enough time. It's blowing plenty cold enough still to keep me comfy in 95*F weather though.



Bad news is, the compressor sounds like a box of marbles at idle. I have a feeling an overhaul of the system is in the not too distant future. I think I will hook up some gauges and try to add an ounce or two to see if I can breathe some life into it for the summer.



Thanks again for all the info, appreciate ya'all

[m3f_JPoland_e17b491a3d]

Your compressor sounds like crap probably because you are running it with low refrigerant. It also could be that your lines are contaminated but seeing as you still have refrigerant in there, that is probably not the case unless you have had work done on it in the past.

It is not hard to add charge but I suggest you do it before running the system any more.