Hello, working on a car for my son that previously had optimal cooling. But the AC got to where it seemed the variable displacement compressor was locked on max setting, it dragged unusually on the engine and produced huge puddles from the condensate drain, compressor would cycle on and off, this car shouldn't do that. I replaced the compressor with a used low miles denso unit and new denso expansion valve. Condensor was new 1 yr prior from hole in it, generic but visually identical replacement. Vac and charged to spec and having problems.
The drag on the engine and puddles of water are gone but the cooling is not right. The car will cool off eventually but I cant leave it like this. Appreciate any help I've worked on ac and studied for years but it is not my forte. Been reading here for days
At 1500rpm max cool/fan recirc w/doors open 10 mins running
94F ambient 47% humidity
94F room temp sens
60-65F center vent temp
evap fin thermistor 53-57F
300-350psi high side hovers around 325
22-27psi low side
elec cooling fan stays same speed unless high pressure nears 350 then goes to max speed (as spec)
max speed pulls it back down to ~300psi
coolant temp sens stays at 197-198 solid
Manual says 22-36 low 199-228 high
Spraying condensor with water dives the high side to 190-200psi.
Driving helps get slightly vent temp but not cold like it should be, doesn't seem to be an airflow problem.
I dont have temp clamps but with ir gun the condensor inlet outlet temps are at least 30deg apart and the condensor surface temp is pretty even maybe 15deg spread bottom to top, nothing stands out there.
Poor cooling Excessive high side pressures 09 ES350 Lexus
- JohnHere
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Re: Poor cooling Excessive high side pressures 09 ES350 Lexus
The low-side pressures aren't too bad, but the high side is much too high, pointing to a condensing problem.
I would attack this problem on two fronts:
1. Replace the fan, check that nothing is obstructing airflow through the condenser, and that all foam seals and shrouds are in place. (The water-spray test confirms poor condensing.)
2. Replace the control valve because the one that came with the used Denso compressor might be faulty. Control valves are relatively inexpensive.
How did you recharge it, by weight or pressures? Lexus vehicles like this one are very sensitive to the refrigerant amount.
I would attack this problem on two fronts:
1. Replace the fan, check that nothing is obstructing airflow through the condenser, and that all foam seals and shrouds are in place. (The water-spray test confirms poor condensing.)
2. Replace the control valve because the one that came with the used Denso compressor might be faulty. Control valves are relatively inexpensive.
How did you recharge it, by weight or pressures? Lexus vehicles like this one are very sensitive to the refrigerant amount.
Member – MACS (Mobile Air Climate Systems Association)
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Re: Poor cooling Excessive high side pressures 09 ES350 Lexus
Just an additional note to what JohnHere said....make sure to inspect between the condenser and radiator. Most debris such as cottonwood and other dirt will get through the condenser fins and matt up on the face of the radiator. Condenser will look clean but the radiator could be blocked.