$1400 later and still no cool air in the cabin
07-22-16, 12:48 PM
#1
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$1400 later and still no cool air in the cabin
Just had the SC400 air cond.system rebuilt , high side pressure 180 psi, low side pressure 30psi. When I leave for the gym here in Miss. around 6 AM I have cool air. Two hours later when I return home the air is barely cool. I have the system on reculate but it's like I'm getting warm air from the outside. I don't think the reculate mode is working. Suggestions, Ideas please. The air cond. in the wife's Lexus would make a great aux. meat locker.
07-22-16, 04:20 PM
#3
Southaven, what specific parts of the A/C system were replaced?
--A/C compressor?
--A/C Condenser?
--A/C Drier?
--A/C Evaporator Core?
--A/C Thermal Expansion Valve?
--A/C High pressure line?
--A/C Low pressure line?
Your compressor does not seem to be putting out overly high pressure but it isn't putting out nominal pressure either. I have forgotten what the optimum high and low side pressures were supposed to be but I thought one of them (high?) was supposed to be about 250psi. I am not an A/C person and my diagnostic knowledge is limited however I replaced all of the items listed on my car last year to get the system working correctly.
A couple of years back I replaced the compressor with a new Denso remanufactured unit and brand new high and low pressure lines.
In the middle of last year I found my Thermal Expansion Valve (TX-V) was stuck and causing 350psi on the high side. I ended up replacing that, the evap core since it was right there also. I installed a new condenser as well even though it wasn't technically bad... just old.
Check densoproducts.com where you will find many of the OEM A/C components for the SC300/400 available to order direct. High and low pressure lines are a Lexus only part.
--A/C compressor?
--A/C Condenser?
--A/C Drier?
--A/C Evaporator Core?
--A/C Thermal Expansion Valve?
--A/C High pressure line?
--A/C Low pressure line?
Your compressor does not seem to be putting out overly high pressure but it isn't putting out nominal pressure either. I have forgotten what the optimum high and low side pressures were supposed to be but I thought one of them (high?) was supposed to be about 250psi. I am not an A/C person and my diagnostic knowledge is limited however I replaced all of the items listed on my car last year to get the system working correctly.
A couple of years back I replaced the compressor with a new Denso remanufactured unit and brand new high and low pressure lines.
In the middle of last year I found my Thermal Expansion Valve (TX-V) was stuck and causing 350psi on the high side. I ended up replacing that, the evap core since it was right there also. I installed a new condenser as well even though it wasn't technically bad... just old.
Check densoproducts.com where you will find many of the OEM A/C components for the SC300/400 available to order direct. High and low pressure lines are a Lexus only part.
07-23-16, 09:32 AM
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Dude,
The Lexus manual states 185 to 213 psi is the normal range for the high side when running the engine for several minutes. The system could simply be a bit undercharged of R134a.
.
The Lexus manual states 185 to 213 psi is the normal range for the high side when running the engine for several minutes. The system could simply be a bit undercharged of R134a.
.
07-24-16, 12:40 PM
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Well here is the rest of the story. I read what Freakness wrote and said to myself, start with the simple solution. I went Autozone and bought a can of AC Pro with the gauge and filler hose. Added about 16 oz and brought the low side pressure up to where to should be based on the ambient temperature. You can hang meat in the cabin of the SC400 now.
07-24-16, 01:01 PM
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Well here is the rest of the story. I read what Freakness wrote and said to myself, start with the simple solution. I went Autozone and bought a can of AC Pro with the gauge and filler hose. Added about 16 oz and brought the low side pressure up to where to should be based on the ambient temperature. You can hang meat in the cabin of the SC400 now.
Dude,
Mmmmmmmmmmmmmmmmmeat
.
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07-24-16, 06:35 PM
#8
^^ The thermal expansion valve. SC's and Soarers of all years use this design. You can buy the same part new from Denso (OE supplier) but you'd also want to keep an eye on how worn your evaporator core is also since that has to come out to install the thermal expansion valve anyway.
When my valve went bad it was mostly stuck closed (I think) which caused a 350psi high pressure condition from the compressor side of the system. This wears out the compressor prematurely (not right away but over some months depending on how new the compressor is).
When my valve went bad it was mostly stuck closed (I think) which caused a 350psi high pressure condition from the compressor side of the system. This wears out the compressor prematurely (not right away but over some months depending on how new the compressor is).
07-24-16, 07:46 PM
#9
I have worked on a/c systems since I was a teenager (I am 50+ now) and I have never known an evaporator core to "wear out". I have seen one or two corrode due to condensation not draining properly, but never wear out. It would be money wasted to just replace since it is out of the car. Expansion valves do plug up and have to be replaced, usually due to a drier turning loose material and contaminating the system. Toyota also employs an EPR (evaporator pressure regulator) on these cars, they can be a source of problems as well. These can create a high pressure situation even if you replace the expansion valve. It's just something that has to be determined from troubleshooting.
^^ The thermal expansion valve. SC's and Soarers of all years use this design. You can buy the same part new from Denso (OE supplier) but you'd also want to keep an eye on how worn your evaporator core is also since that has to come out to install the thermal expansion valve anyway.
When my valve went bad it was mostly stuck closed (I think) which caused a 350psi high pressure condition from the compressor side of the system. This wears out the compressor prematurely (not right away but over some months depending on how new the compressor is).
When my valve went bad it was mostly stuck closed (I think) which caused a 350psi high pressure condition from the compressor side of the system. This wears out the compressor prematurely (not right away but over some months depending on how new the compressor is).
07-26-16, 06:53 AM
#10
Hey guys,
I had a issue with my AC last year when I bought my SC400. The AC would work for about 5 minutes and then the compressor would kick off and I would get that infamous green blinking light on the climate control inside. It had normal PSI on high and low side, and system was filled up with proper amount of 134. I went through and replaced my expansion valve, high pressure switch?, and the rpm sensor (not sure what that one is called its been awhile) on the actual compressor. None of this worked and the problem ended up being the actual Climate Control unit inside the car had died and was telling the compressor to shut off. I hope this helps someone!
good luck
I had a issue with my AC last year when I bought my SC400. The AC would work for about 5 minutes and then the compressor would kick off and I would get that infamous green blinking light on the climate control inside. It had normal PSI on high and low side, and system was filled up with proper amount of 134. I went through and replaced my expansion valve, high pressure switch?, and the rpm sensor (not sure what that one is called its been awhile) on the actual compressor. None of this worked and the problem ended up being the actual Climate Control unit inside the car had died and was telling the compressor to shut off. I hope this helps someone!
good luck
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