I've got a '99 Pathy thats giving me an odd Air Conditioning problem.
First of all, I just did a ton of 105k maintenance including:
• New Radiator and upper/lower hoses
• Water pump
• Thermostat
• Timing belt
• Alternator (a bearing was going so I replaced it)
• Spark plugs
Before all of the work the Air Conditioner worked like a dream. After all the work I put into it the Air Conditioner will only get Cold In the morning when the ambient temps are ~70 or below
When it heats up to the mid 90's F here in SoCal, it only blows Cool air (it never gets Cold)
The compressor clutch engages and disengages fine.
I had the refrigerant levels checked at pep boys and they said it was fine (it was in the morning so the A/C system was working fine)
I've read about something called the Thermo Control Amplifier in the dashboard under the glove box that has been known to cause problems.
Any ideas & experiences will be greatly appreciated
Intermittent Air conditioning
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jpjm132003
- Posts: 13
- Joined: Thu Sep 30, 2010 9:56 am
- Car: 2005 Nissan Altima 2.5s
Re: Intermittent Air conditioning
A/C on, clutch engaged compressor spinning, is it a V6 piston operated, feel the output large compressor hose, should be cold. That enters the evaporator which is the heat exchanger feeding cold air in the cab. The return line should be a bit warmer than the input line.
Feel these lines in am when cool, then again when in pm being warmer ambient. Are the the same or different in temperature.
Ambient does make some difference but when the freon changes state it does so when compressed. There is a plate within the compressor to vary the compressors rate of change, if stuck that compressor may only be able to discharge at the lower end.
Other than taking it apart and looking you can try dislodging the compressor's swash plate by giving it a good solid thud with a weighted hammer, but choose an area of the compressor that will do the best in vibration without breaking. This is a very iffy thing to do and should be done while the compressor is operating.
If a V6 compressor it is also expensive.
Also if you have a drier installed that drier may be saturated or plugging. Even the front mounted condenser can be plugged. Feel the heat exchangers both the internal evaporator and the front mounted condenser.
The evaporator under normal use is cold 40F to 55F while the condenser is hot as it removes cabin heat. So compare them, feel around the drier, while all this system operates liquid to gas to liquid transformation is taking place can you hear this, use a stethoscope on pipes and heat exchangers.
I am assuming you have no tools for really examining the cooling system so your hands, eyes and ears are needed.
The system is acting as if it is low on freon but I must rely upon your word that it is up, how did they test this?
Feel these lines in am when cool, then again when in pm being warmer ambient. Are the the same or different in temperature.
Ambient does make some difference but when the freon changes state it does so when compressed. There is a plate within the compressor to vary the compressors rate of change, if stuck that compressor may only be able to discharge at the lower end.
Other than taking it apart and looking you can try dislodging the compressor's swash plate by giving it a good solid thud with a weighted hammer, but choose an area of the compressor that will do the best in vibration without breaking. This is a very iffy thing to do and should be done while the compressor is operating.
If a V6 compressor it is also expensive.
Also if you have a drier installed that drier may be saturated or plugging. Even the front mounted condenser can be plugged. Feel the heat exchangers both the internal evaporator and the front mounted condenser.
The evaporator under normal use is cold 40F to 55F while the condenser is hot as it removes cabin heat. So compare them, feel around the drier, while all this system operates liquid to gas to liquid transformation is taking place can you hear this, use a stethoscope on pipes and heat exchangers.
I am assuming you have no tools for really examining the cooling system so your hands, eyes and ears are needed.
The system is acting as if it is low on freon but I must rely upon your word that it is up, how did they test this?
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jpjm132003
- Posts: 13
- Joined: Thu Sep 30, 2010 9:56 am
- Car: 2005 Nissan Altima 2.5s
Re: Intermittent Air conditioning
Hey Thank you for the detailed advice. However, you are right; I do complicated work but my A/C knowledge is pretty much what I have learned through this experience.
All I know is that the clutch on the compressor is engaging and the return line never gets ice cold like it used to.
My uncle works for Freigtliner and he has equipment and knows what he is talking about. We are going to check pressures, evacuate the system, and he is going to use his knowledge to narrow it down to the problem.
He mentioned everything you mentioned as a potential problem.
I will post the results on Saturday to try to help with anyone else's problem.
All I know is that the clutch on the compressor is engaging and the return line never gets ice cold like it used to.
My uncle works for Freigtliner and he has equipment and knows what he is talking about. We are going to check pressures, evacuate the system, and he is going to use his knowledge to narrow it down to the problem.
He mentioned everything you mentioned as a potential problem.
I will post the results on Saturday to try to help with anyone else's problem.
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jpjm132003
- Posts: 13
- Joined: Thu Sep 30, 2010 9:56 am
- Car: 2005 Nissan Altima 2.5s
Problem Resolved
I ended up paying a local A/C "Expert" for what he thought the issue was.
He determined that the internal flap of the A/C Compressor wasn't working properly.
So I went to a place in Garden Grove, CA called A/C Exchange.
They do good work for cheap.
They replaced the A/C Compressor, condenser, expansion valve, and cleaned the pipes with an "oil based solvent"
The parts and labor costed me $565 vs the dealer & experts quote of 1300+
No further problems and the Pathy onces again blows ice cold every day.
It wasn't a cheap or easy fix but it has been resolved and determined that the AC compressor was at fault
Online reviews for A/C exchange are pretty low, but I had a great experience. They did the work for less than half the dealers quote.
He determined that the internal flap of the A/C Compressor wasn't working properly.
So I went to a place in Garden Grove, CA called A/C Exchange.
They do good work for cheap.
They replaced the A/C Compressor, condenser, expansion valve, and cleaned the pipes with an "oil based solvent"
The parts and labor costed me $565 vs the dealer & experts quote of 1300+
No further problems and the Pathy onces again blows ice cold every day.
It wasn't a cheap or easy fix but it has been resolved and determined that the AC compressor was at fault
Online reviews for A/C exchange are pretty low, but I had a great experience. They did the work for less than half the dealers quote.