A/C blowing warm air?

Tiny
MATTSTORMS42
  • MEMBER
  • 2008 MITSUBISHI GALANT
  • 2.4L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 260,000 MILES
The compressor engages once then stops. A/C is blinking. Low side and high side pressure read 50 PSI, "see pic". System was charged with ez chill refrigerant can.
Tuesday, July 1st, 2025 AT 3:47 PM

7 Replies

Tiny
MECHTRIX
  • MECHANIC
  • 382 POSTS
Ive seen this happen before just becuase there wasnt enough refrigerant in the system these systems take a spe ifued amount wich must be measured out carfully each system is different with its own required amount it uses. Also to much or not enough oil. Theres a few things that can cuase this problem like
1. Did you evecuate the system first befor filling it . Was a manifold and or a vacume pump used to mearure the pressure inside the system to establish a starting point for the filling or evacuation process?
2. Did the can of refrigerant say it was the type with or without oil in it. Some have it some dont. Ive seem people ad the tyoe with oil and over fill it a d damage the pump. Did you drain it?
3 did you fill it with the eng running and with the ac on
4. How did you determine the amount of oil was in the systen befor you started the evacuation and or refilling process ? Did you
Check all electronic devices associated with the ac system to see if any where faulty
These systems can be damaged easily. Always use extream caution when working with these systems.

That said "use your own best judgement if you decide to try this
. It could damage the system if you dont take into acaount the things ive meantiined above
. Please read this carfully before attempting to rapir it
. From my own experience .
Somtimes this happens if you simply dont have enough or to much refrigerent or oil or both uhin the system. You need to determine exactly how much your gonna need if any before hand. If its determined that you dont have enough you can ad some slowly while its running with the ac on. And watch the ac punp clutch cycle on and off as you ad some refrigerant. When doing so you might notice the clutch staying on a bit longer and longer as you ad some. And the high side increase in pressure as you fill it slowly using short burst. Wait 20 seconds or so in between times giving it a chance. To fully circulates through the system. Keep watching till the pump clutch cycles on and stays on for up to one min then stop filling dont go beond this point it can damage the pump . If all seems well it should be good by then let it run a while the try turning the ac of wait a few min and turnit back on you should have cold air shortly after its turned back on .. This has worked many times for me on many different cars where this problem accured but only works when youve determined it didnt have enough refirgerant in it. But keep in mind its up to you if you want to try this. Good luck hope this helps
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Tuesday, July 1st, 2025 AT 9:49 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
I agree with MECHTRIX, there is not enough refrigerant inside the system. Here is a video to help you charge the system correctly.

https://www.youtube.com/watch?v=4EqdrBVb0sY

Please go over this guide and get back to us.
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Friday, September 5th, 2025 AT 5:22 PM
Tiny
MATTSTORMS42
  • MEMBER
  • 40 POSTS
Ty, expansion valve is bad. Have frozen bolt. Cant get a food "bite" on it from fire wall. Can you send diagram for procedure to take dash off
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Saturday, September 6th, 2025 AT 6:57 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Can I ask how you found this out, what was the high side reading? Yes the bolts for the expansion block can get seized due to rust and corrosion. To remove the evaporator the dash and HVAC module must be removed which is a big job. Please start a new thread for this issue. So I suggest to use wd40 and let it sit overnight, then use a quality tool to try ad remove it.
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Saturday, September 6th, 2025 AT 4:10 PM
Tiny
MATTSTORMS42
  • MEMBER
  • 40 POSTS
Blowing hot air. Had leak in a pitted corroded receiver/drier. Compressor would function. New pressure switch. Lowside line not cold to touch. Also captured refridgerant and vacuumed down system. Refilled with appropriate amount of refridgerant no change.
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Sunday, September 7th, 2025 AT 6:31 AM
Tiny
MATTSTORMS42
  • MEMBER
  • 40 POSTS
  • 2008 MITSUBISHI GALANT
  • 2.4L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 264,000 MILES
I have a bad expansion valve I have to replace. I went through firewall and was able to disconnect high/low side ac lines and get 5mm bolt and expansion valve block off. I was able to get 1 of 2 4mm allen bolts off expansion valve. The upper allen bolt seems to be stuck. Is there another way to access the expansion valve so I can remove this bolt.

Thank you
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Sunday, September 7th, 2025 AT 9:09 AM (Merged)
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Nope, you must get the other bolt out, I would use a large crescent wrench to help support he valve so you don't break the evaporator core. Also, use a quality Allen tool to help avoid rounding the bolt.
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Sunday, September 7th, 2025 AT 9:09 AM (Merged)

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