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2004 SC430 167k miles - My son just bought this car and the A/C recently stopped blowing cold after a few weeks.
We assumed it simply needed a recharge, but the pressure gauge on the refrigerant shows maximum pressure when hooking up.
The compressor appears to be running and the clutch is engaged.
I'm not sure exactly what to do next as far as diagnosing the problem. Any ideas? Thanks!
Good morning, I have a 2006 sc430 with 207,000 miles bought it with 189,000. My a/c was working fine last summer and the next day it was blowing hot air. Hooked up the guages and the low side pegged out while the high side was really low reading nothing. I've been to an automotive a/c class and had a good instructor. I always knew how to charge but diagnosis is where it is and I learned a lot and how to do it within the standards abiding by EPA rules and regulations. I discharged the system by evacuating the freon into an empty cylinder with my guages. I removed the serpentine belt and compressor. The original denso compressor has a mechanical valve that let's the freon convert from liquid to high pressure gas. If this valve is the original it gets caked up over time and does not allow the compressor to compress in layman terms resulting in the low side of the guage pegging out. The part cost like 20.00 bucks. Got it off of ebay. I matched it up by eyesight. Removed it. You need a set of c clip pliers put about 4oz of compressor oil and replaced the o-ring and part. Reinstalled the compressor and replaced the belt for good measure. Recharged the system and she is blowing ice cold. I have a picture of the part. Dont replace the compressor keep the original one. It will last forever if serviced properly.
Fantastic information Nook1. I'm assuming the compressor oil you referred to is used to coat the control valve?
Yes sir Just to replace any oil that may have spilled while removing the valve or compressor after disconnecting .but yes to lubricate the compressor and valve. I didn't mention but a/c control valve under your foot pedal that connects to the tube inside the engine bay. I replaced that first and no dice. That control valve fixed the problem. Good luck and if you have any questions just ask but its pretty straight forward. Don't forget to draw it down after replacement and you should be good to go.
Good morning, I have a 2006 sc430 with 207,000 miles bought it with 189,000. My a/c was working fine last summer and the next day it was blowing hot air. Hooked up the guages and the low side pegged out while the high side was really low reading nothing. I've been to an automotive a/c class and had a good instructor. I always knew how to charge but diagnosis is where it is and I learned a lot and how to do it within the standards abiding by EPA rules and regulations. I discharged the system by evacuating the freon into an empty cylinder with my guages. I removed the serpentine belt and compressor. The original denso compressor has a mechanical valve that let's the freon convert from liquid to high pressure gas. If this valve is the original it gets caked up over time and does not allow the compressor to compress in layman terms resulting in the low side of the guage pegging out. The part cost like 20.00 bucks. Got it off of ebay. I matched it up by eyesight. Removed it. You need a set of c clip pliers put about 4oz of compressor oil and replaced the o-ring and part. Reinstalled the compressor and replaced the belt for good measure. Recharged the system and she is blowing ice cold. I have a picture of the part. Dont replace the compressor keep the original one. It will last forever if serviced properly.
That is FANTASTIC information to know! I wish I had learned that a couple of summers ago.
That is FANTASTIC information to know! I wish I had learned that a couple of summers ago.
Yes its a good thing to know during the summer months. I am a Army Combat Vet and worked on Apache helicopters. They have 2 huge compressors to cool down the electronics. If you can find leaks and trouble shoot that monster you have a job for life lol!
If you wind up replacing the compressor thats cool but they are so expensive even for a remanufactured one. Not even talking about new yet. 22.00 , a little time, some guages and patience and she will be blowing cold again.
Yes sir Just to replace any oil that may have spilled while removing the valve or compressor after disconnecting .but yes to lubricate the compressor and valve. I didn't mention but a/c control valve under your foot pedal that connects to the tube inside the engine bay. I replaced that first and no dice. That control valve fixed the problem. Good luck and if you have any questions just ask but its pretty straight forward. Don't forget to draw it down after replacement and you should be good to go.
Saving this in case I run into AC issues in the future. Thanks for the heads up. Any chance you have pictures of where the control valve is located?
Saving this in case I run into AC issues in the future. Thanks for the heads up. Any chance you have pictures of where the control valve is located?
Yes dont mind sharing info thats what we are here for. Didn’t take a picture but its on the side of the compressor. You have to remove it to access it unfortunately. It's not hard.. took more time jacking it up and removing the undercover.
The circle in red is where that control valve is. It comes with the 3 orings just have to make sure you lube them with compressor oil .
I put gauges on mine and the low and high pressure side read about 100 psi with the compressor engaged which says it is not compressing. I was thinking the compressor was shot but after reading this I am beginning to wonder. Would this valve cause such a condition? Oh, the a/c was working fine one day and not the next. It only has 70k miles on a 2005.
Last edited by mildsc430; 05-27-22 at 06:30 AM.
Reason: Added info
I put gauges on mine and the low and high pressure side read about 100 psi with the compressor engaged which says it is not compressing. I was thinking the compressor was shot but after reading this I am beginning to wonder. Would this valve cause such a condition? Oh, the a/c was working fine one day and not the next. It only has 70k miles on a 2005.
I think I have a picture of what the a/c guages looked like when the valve froze up Low side high / high side low is a condition and fix for that. The A/C valve. If both sides are high you are right that ultimately means the compressor isnt compressing the liquid into gas to make the cooling through the evap inside the car. So yes a new compressor may be warranted. I would at least change out the i cant think of the name but the a/c regulater just under the drivers foot pedal. I changed mine out before the valve on the compressor and it still read the same low side high/high lo
My pressures are about 75 on the low side, 100 on the high side, compressor engaged. When the engine is off, both at 100. Guess it is time to pull the compressor.
Oh, and I did the diagnostics from the dash and no codes (00).
My pressures are about 75 on the low side, 100 on the high side, compressor engaged. When the engine is off, both at 100. Guess it is time to pull the compressor.
Oh, and I did the diagnostics from the dash and no codes (00).
Yes unfortunately but its an easy task and not that pricey. Just remember to get the drier and condenser as a package, oil your compressor, vacuum it down check for leaks and recharge.
Yes unfortunately but its an easy task and not that pricey. Just remember to get the drier and condenser as a package, oil your compressor, vacuum it down check for leaks and recharge.
OK, I will bite. How easy? Is there an instructional video or step-by-step available? Or is it one of those "if you have to ask, don't try it"?
Also, when you did your valve change did you replace the condenser as well?
05-04-21, 09:28 PM
A/C Problems
