A/C blowing warm air at IDLE

LJMolina

LJMolina

TJ Enthusiast
Joined
Dec 11, 2019
Messages
122
Location
Broken Arrow, OK
Ok, I have a new issue... my 2006 LJU automatic, my air conditioning works fine when I am on the highway/street moving. When I stop for more than 5 minute or so such as stopped for a train or waiting for food at a fast food restaurant the vents will start to blow warmer air out of them. They blow warm air just not near as cool as when the jeep is in motion. All my flap settings work fine, my engine coolant temp is rock steady at 210,... I put some gauges on the HIGH/LOW (260psi/41psi@80degrees) so the pressures are in the green for the outside temp range. My radiator mechanical fan seems to be working fine but i does get unbearably hot in the engine bay (might be normal?) Condenser is clear of debris as I power wash it.

any ideas? I tried to find other forums but really most stopped in the middle of the threads with no solutions.

The only thing I can think of, I do have grille inserts and I do feel the radiator fan suction through the inserts... I just dont know if the airflow is sufficient. I will remove them later today and post my result but in the meantime I like to hear what everyone has to say.

Thanks in advance...
 
(260psi/41psi@80degrees)
Click to expand...

Your pressures look perfect for the ambient temperature, indicating that the condenser is getting plenty of flow, how is the vacuum at idle (which it should be the strongest), could have a a blend door that is moving at idle, letting some heat from the heater core in??
 
Last edited:
Engine fan clutch could be getting weak also.
Edit to add: I redid the cooling system when I bought mine but didn't do the fan clutch. Went to the ORV park this spring and got the warning to CHECK GAUGES. Sure enough the engine temp had climbed above the magic 210. The fan clutch spun freely.
 
So, the engine clutch fan is solid. All vacuum lines have no cracks or leaks.
The only thing last to check is to take a look at the blend doors.
 
ljmolina said:
Ok, I have a new issue... my 2006 LJU automatic, my air conditioning works fine when I am on the highway/street moving. When I stop for more than 5 minute or so such as stopped for a train or waiting for food at a fast food restaurant the vents will start to blow warmer air out of them. They blow warm air just not near as cool as when the jeep is in motion. All my flap settings work fine, my engine coolant temp is rock steady at 210,... I put some gauges on the HIGH/LOW (260psi/41psi@80degrees) so the pressures are in the green for the outside temp range. My radiator mechanical fan seems to be working fine but i does get unbearably hot in the engine bay (might be normal?) Condenser is clear of debris as I power wash it.

any ideas? I tried to find other forums but really most stopped in the middle of the threads with no solutions.

The only thing I can think of, I do have grille inserts and I do feel the radiator fan suction through the inserts... I just dont know if the airflow is sufficient. I will remove them later today and post my result but in the meantime I like to hear what everyone has to say.

Thanks in advance...
Click to expand...

Actually at 80* the low pressure is fine, but the high pressure is some what high like there is either moisture or air in your system or the metering orifice is not doing its job. Pressures for 80* LOW 40-50 and HIGH 175-210.
The pressures you posted are at idle or when the engine is at 1800 RPMs ?
 
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