AC problem
06-18-2017, 12:44 PM
#1
AC problem
My 02 is having a issue where the high side pressure builds to 375 psi at a stop and the compressor kicks off. The RPM does not change this. But when I drive over 25 MPH the ac compressor runs perfectly and does not turn off, again the rpm does not change the outcome. Overcharged? Or water/air in the system? Can't think of anything. Any feedback would be great. THANKS!
06-18-2017, 03:47 PM
#2
Senior Member
Join Date: Sep 2012
Location: The Northeast
Posts: 681
Check out this general A/C troubleshooting guide from Denso:
http://densoautoparts.com/sites/defa...ing%20tips.pdf
What's the low side like?
http://densoautoparts.com/sites/defa...ing%20tips.pdf
What's the low side like?
06-18-2017, 06:47 PM
#4
Make sure both cooling fans are coming on. Both fans should come on as soon as the AC is turned on. If one of the fans fails it will cause your exact symptoms.
The condenser gets too hot while stopped but cools off when moving and air flows through it.
The condenser gets too hot while stopped but cools off when moving and air flows through it.
06-18-2017, 10:36 PM
#5
Would the condenser get that hot right away? this happens even from the car sitting all night, the compressor will run when the car starts and will shut off due to high pressure. ill have to double check the fan, im almost positive it turns on but ill make sure.
06-19-2017, 12:47 AM
#6
Yeah. The condenser will get hot right away. It has nothing to do with engine temp or RPM.
Without both fans you'll only have AC for a very short time unless you're moving. Especially in a hot climate.
Both fans should come on with the AC even if the car is cold. If not, that's your problem. The fan motors do fail too. It's not uncommon.
Without both fans you'll only have AC for a very short time unless you're moving. Especially in a hot climate.
Both fans should come on with the AC even if the car is cold. If not, that's your problem. The fan motors do fail too. It's not uncommon.
Last edited by Derrick2k2SE; 06-19-2017 at 12:52 AM.
06-19-2017, 07:23 AM
#8
alright so i checked out the fan, and it did not turn on once. lucky for me it just rained and cooled down a little, so the ac compressor stayed on. So i hooked up my manifold gauge and the high side was starting to shoot up until I splashed water on the condenser and after that the pressures hung around 200-250, and lows between 10-20. I refereed to the FSM and based on that id say its overcharged AND my fan is not working.
06-19-2017, 08:53 AM
#9
Replace the fan motor first. There's no question that needs to be done. Splashing water on the condenser isn't the same as having a fan.
Swapping the fan motor is not a difficult repair. I'd turn the AC off when coming to a stop till you get it handled.
Unless it was it recently worked on, it shouldn't be overcharged or contaminated.
Swapping the fan motor is not a difficult repair. I'd turn the AC off when coming to a stop till you get it handled.
Unless it was it recently worked on, it shouldn't be overcharged or contaminated.
06-19-2017, 02:21 PM
#10
Senior Member
Join Date: Apr 2016
Location: Florida
Posts: 972
There's usually release valve in the event it gets overcharged!
Not sure at what psi it jumps up to(545psi?) but it won't explode unless that's been bypassed.
Not sure at what psi it jumps up to(545psi?) but it won't explode unless that's been bypassed.
Last edited by maximatech12; 06-19-2017 at 04:52 PM.
06-19-2017, 10:56 PM
#11
It popped the release valve one morning upon a start up. I splashed water on the condenser because thats what the Fsm said to do to see if it is overcharged. But now i have more problems, the ac isnt cooling at all as of this afternoon, ill have to see what my pressures are in the morning.
06-20-2017, 12:06 AM
#12
Just replace the fan motor then see what else it's doing. There's no point in checking any pressures as long as the condenser is overheating. You'll never get any useful readings. The fan has to be fixed no matter what.
Whatever you do, don't start trying to add or remove any refrigerant.
Whatever you do, don't start trying to add or remove any refrigerant.
06-20-2017, 11:16 AM
#14
Cooling fan motor. Both sides are the same part #.
Just get the motor and not the whole assembly.
The motor can usually be found in stock locally as well. The price may be very close and you'll have it today.
When you do the install you have to disconnect the radiator top hose from the radiator. It's tempting to try to wiggle the assembly around it but it wont go. You wont lose a lot of coolant but have something to catch it under the car.
Just get the motor and not the whole assembly.
The motor can usually be found in stock locally as well. The price may be very close and you'll have it today.
When you do the install you have to disconnect the radiator top hose from the radiator. It's tempting to try to wiggle the assembly around it but it wont go. You wont lose a lot of coolant but have something to catch it under the car.
06-20-2017, 07:41 PM
#17
Replaced the fan motor, fixed that side, other motor went out when I put it back together, replaced that one as well. both fans work perfectly now. Checked pressures, and based on the FSM my compressor is gone...... 70-80 high, didnt change with rpm, high side was 140-150 didnt change upon rpm. No cool air, and the high and low side were the same temperature. Do yall think that its the compressor or am i missing something here?
06-20-2017, 08:17 PM
#18
Is the compressor kicking on and do the fans come on with the AC? Even if the compressor is cooked it should still kick in. You should be able to hear it or watch it if you have someone who can push the button.
I'm not sure about these cars but some need to be reset if the pressures go out of spec too many times. I know GM does that to protect the system.
Check the FSM to see if there's a reset required. I just don't know off hand.
It doesn't seem right that it would be completely cooked like that.
I'm not sure about these cars but some need to be reset if the pressures go out of spec too many times. I know GM does that to protect the system.
Check the FSM to see if there's a reset required. I just don't know off hand.
It doesn't seem right that it would be completely cooked like that.
06-20-2017, 10:50 PM
#19
The compressor kicks on and stays on, both fans run. Based on the pressures and what the service manual says it is leading to a bad compressor. Ill look into a pressure reset. I think I had multiple problems on my hand lol. Ill let you know what I find out within the next day or two.
06-21-2017, 05:42 AM
#20
It may have gotten cooked by running without the fan.
It may be cost effective to get a diagnosis from an AC professional at this point. Get a solid diagnosis so you're not guessing.
If you want to do the repair yourself, the shop can remove the refrigerant and recharge it when you're done. This includes vacuuming the moisture out of the system. Very important.
It may be cost effective to get a diagnosis from an AC professional at this point. Get a solid diagnosis so you're not guessing.
If you want to do the repair yourself, the shop can remove the refrigerant and recharge it when you're done. This includes vacuuming the moisture out of the system. Very important.
06-21-2017, 03:04 PM
#21
Just got it diagnosed at a local Firestone, confirmed the compressor was gone. Next step for me is to find out the sequence of evacuation and when or if to flush the system. Would I even need to flush it? do I evac it the replace then replace the compressor, or replace the compressor then evac, then recharge. and should I replace the drier and expansion valve. This is more than I was hoping haha
I really appreciate all the help!
I really appreciate all the help!
06-21-2017, 04:15 PM
#22
That sucks. probably killed it running without the fan.
*First you have a shop evacuate the refrigerant.
*Then you take it home and replace the components.
*Once you've replaced the components you bring it back to the shop and have them vacuum it down and recharge it. They'll know what to do so you don't have to worry about that exact process. They'll hold it at Vacuum to remove moisture and test for leaks.
*Finally, you drive home enjoying your nice cool AC.
You'll want to replace the drier since you'll be opening the system to moisture. Not sure about the expansion valve. See what the shop says.
*First you have a shop evacuate the refrigerant.
*Then you take it home and replace the components.
*Once you've replaced the components you bring it back to the shop and have them vacuum it down and recharge it. They'll know what to do so you don't have to worry about that exact process. They'll hold it at Vacuum to remove moisture and test for leaks.
*Finally, you drive home enjoying your nice cool AC.
You'll want to replace the drier since you'll be opening the system to moisture. Not sure about the expansion valve. See what the shop says.
06-21-2017, 05:54 PM
#24
Senior Member
Join Date: Apr 2016
Location: Florida
Posts: 972
If you do the p/s belt i highly recommend disconnecting the hpp/s hose from the pump first!
The pump has to be lowered to slip the old one off then new one on. This puts a HUGE strain the send/return hoses.
If its the compressor the evaporator should be frozen up right?
The pump has to be lowered to slip the old one off then new one on. This puts a HUGE strain the send/return hoses.
If its the compressor the evaporator should be frozen up right?
06-21-2017, 07:28 PM
#25
If you do the p/s belt i highly recommend disconnecting the hpp/s hose from the pump first!
The pump has to be lowered to slip the old one off then new one on. This puts a HUGE strain the send/return hoses.
If its the compressor the evaporator should be frozen up right?
The pump has to be lowered to slip the old one off then new one on. This puts a HUGE strain the send/return hoses.
If its the compressor the evaporator should be frozen up right?
Screwing with the hose is a pain and there's no need.
Just release the tensioner and the belt will loosen till it can be removed. There's no strain on the hose at all.
06-21-2017, 09:37 PM
#26
Awesome, i won't be messing with the PS belt, put a new one on 5k ago but that would make sense to do it if I needed it. I'll be starting the compressor replacement process Friday most likely, I'll replace the compressor, drier, and most likely the expansion valve since it comes with the kit. As well as whatever O-rings I come in contact with. I'll let y'all know how it goes and I really appreciate the help once again.
would y'all recommend replacing the condenser? Been reading where it might be a good idea but it's 60$ and 60$ is 60$ lol.
would y'all recommend replacing the condenser? Been reading where it might be a good idea but it's 60$ and 60$ is 60$ lol.
Last edited by VQ35maxima=Beast; 06-21-2017 at 09:41 PM.
06-27-2017, 05:54 PM
#30
Just got everything installed, ended up not doing a expansion valve, just did drier, and compressor. Drained the 1.5oz of oil from the compressor, and im taking it to get evacuated, oiled, and filled up. Lets hope there are no leaks!
06-27-2017, 06:41 PM
#31
Senior Member
Join Date: Dec 2016
Location: Wisconsin
Posts: 432
After reading this thread, I'm super hesitant to use my A/C since one of my radiator fans is not working. My A/C still works, but it could be colder. I'm hoping when I replace the motor, it gets colder.
Good luck with your A/C!
Good luck with your A/C!
06-28-2017, 06:56 AM
#32
The rest of the system isn't.
06-28-2017, 07:38 AM
#33
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Join Date: Dec 2016
Location: Wisconsin
Posts: 432