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Ac odd issue

Old Aug 23, 2023 | 07:48 AM
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Default Ac odd issue

Hey guys,

Got a strange one. Checked my fan running perfectly. Both, hi and low side pressures within spec. Freon filled to 1.1 lbs.

At the evap core. It’s 34 degrees scanning with temp laser. Out of the vents it’s 68 degrees with dials set to 60.

Seems to get colder when moving. Kinda stumped on this. Tested the blender doors and they seem to all be working… unless they are slipping.

Only thing I haven’t done is replace that in cabin temp sensor, outside temp sensor or engine coolant sensor since I think all those are tied to the ac.

Also, ac is considerably colder when car is cold. If I shut it off and go run some errands. It struggles to get to a cool temperature. Unless driving for some time on expressway. Above 80 degrees out the car ac performance is also degraded.

Any help appreciated before I throw in the towel.

Last edited by Petera90; Aug 23, 2023 at 08:00 AM.
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Old Aug 23, 2023 | 08:02 AM
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Sounds like restricted airflow across the condenser (gets colder when moving)…I’d also make sure it’s clean of sand and dirt or other debris…good idea to clean it maybe once every 2 years with air or water.
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Old Aug 23, 2023 | 08:09 AM
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Just an observation, but the effectiveness of the cooling ability of your AC system is dependent upon the rate of heat exchange provided by the condenser. And the condenser sits up front, so it’s the first to get clogged with leaves, bugs, dirt, or anything else sucked up in there. Providing more air flow helps that situation somewhat, which is consistent with what you are observing at with higher speeds.
EDIT: c5diag beat me to it on that point
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Old Aug 23, 2023 | 08:27 AM
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If you're seeing 34 degrees at the evaporator, that is plenty cold, so the system is working. I know you said you investigated the blender doors, but it seems to me that the problem is there. Either a problem with the blender door itself, or the controls for the blender door.
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Old Aug 23, 2023 | 08:34 AM
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Don’t see how the OP is getting a temp gun on the “Evaporator” ??…basically the dash has to come apart.
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Old Aug 23, 2023 | 08:41 AM
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Originally Posted by C5 Diag
Don’t see how the OP is getting a temp gun on the “Evaporator” ??…basically the dash has to come apart.
I'm assuming he is getting the temp from the lines at the firewall just before going into the evaporator.
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Old Aug 23, 2023 | 08:41 AM
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Originally Posted by C5 Diag
Don’t see how the OP is getting a temp gun on the “Evaporator” ??…basically the dash has to come apart.
sorry the line in firewall.
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Old Aug 23, 2023 | 08:50 AM
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OK, well a blend door issue wouldn’t cool the cabin down more as the speed of the car increases.
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Old Aug 23, 2023 | 08:52 AM
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Originally Posted by C5 Diag
OK, well a blend door issue wouldn’t cool the cabin down more as the speed of the car increases.
Im gonna clean out the condenser and radiator. I assume it’s never been done. Car only has 22k miles. So I’ll see if that works. Have a feeling it should solve it all
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Old Aug 23, 2023 | 08:57 AM
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Originally Posted by Petera90
Im gonna clean out the condenser and radiator. I assume it’s never been done. Car only has 22k miles. So I’ll see if that works. Have a feeling it should solve it all
Where did you take these readings ??…at the TXV ??
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Old Aug 23, 2023 | 08:59 AM
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Originally Posted by C5 Diag
Where did you take these readings ??…at the TXV ??
yes all those lines running at the back of the firewall. The low side is also frosted and freezing.

the other odd issue is the center vents driver is always 7 degrees warmer.
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Old Aug 23, 2023 | 09:23 AM
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Dirty condenser can cause frosting on the low side…I’d address that first and we can try to help you from there.
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Old Aug 23, 2023 | 05:26 PM
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Cleaned the condenser and a **** ton of dust and leaves came out. The center vents read as follows: 56 degrees for passenger side. 63 for driver side.

Driver side vent by door 56 degrees. Passenger side vent by door 56.

all actuators seem to be working. Just don’t understand the center vents difference in temp. Unless there’s a vent seal leak…
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Old Aug 23, 2023 | 06:17 PM
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Probably something to do with the Law of the Seven Degrees of Separation.
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Old Aug 24, 2023 | 08:33 AM
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Originally Posted by FatsWaller
Probably something to do with the Law of the Seven Degrees of Separation.
lol that explains it
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