FOMULA91

iTrader: (3)

I understand its common for the A/C related compartment failure for the 06-13 Civic.
Most of the problem I see is the Omoron relay failure, pressure switch failure, clutch shim gap problem and of course, low/high on refrigerant cause the compressor clutch not to engage.

I also read many article with intermittently cooling problem which cold air switch over to warm air caused by evaporator freeze up do to expansion valve failure .

The A/C on my mothers 09 Civic (less than 40K miles original owner) never really had ice cold air to start with but she hardly use the A/C.

Last week, I was making a trip out of state and used my mothers Civic. It wasn't blowing cold air so I simply added 12 oz of refrigerant and it started to blow cold air right away. It was working fine during the trip but I simply thought there might be a leak somewhere so i had my brother use the A/C machine to double check. The pressure check good and the system was actually overcharged (1.14 lbs and the Civic require 15.9 oz) so my brother drain and recover to spec.

Yesterday, the A/C was working normally but this morning, it completely stopped working.

After inspecting the Civic, the problem I found was that it only blows warm air. If I turn the **** all the way on the heater, it gets HOT and the blower motor if working fine but stays somewhat warm if I turn the **** back to cold.
When I turn ON the A/C MAX button, the condenser fan and the compressor clutch will turn on and off normally so it does not have the clutch engagement issue. However, it only blows warm air.

Found info on how to Troubleshoot the HVAC System and perform the test but no code came up.

I doubt the refrigerant is gone but going to have my brother check compression on the A/C system tomorrow to see if the compressor is working normally even though the clutch is engaging.

Any feedback or comment will be appreciated.

holmesnmanny

before you add refrigerant it's blowing hot and after you add refrigerant it blows cold so it's likely it has a substantial leak

add some uv dye then add some refrigerant and run it for a bit, then park it in the dark and use some uv glasses and light to check for leaks

FOMULA91

iTrader: (3)

No leak in the system.

Got the result from my brother and the compressor is very weak and cannot charge the high pressure. So the i'll be replacing the compressor next week.

holmesnmanny

if it's blowing cold at any point in time then the compressor would appear to be good otherwise it wouldn't blow cold

sumdewd

x2 on what holmesnmanny said. Did you have him recover and weigh the refrigerant again after the "weak" pressure check? I'm sorry, but I find it hard to believe that it's working fabulous and then isn't working well until refrigerant is added again--- with no leak.

Evaporator freeze up with the defective expansion valve can be verified by reading 0 or vacuum on the low side with absurd pressures on the high side.

How did your brother check for leaks? With a UV light and dye? With an electronic sniffer? By hooking his gauges up to check pressures? Simply measuring low and high pressures to gauge compressor condition is useless without factoring in humidity, charge level, oil amount, ambient temperature, sunlight, engine speed, blower setting, and condenser cleanliness/airflow.

Based on my own observations with a digital refrigerant scale, a TXV based system can run and not short cycle(it's not a clutch cycling orifice tube system) on only 3oz of refrigerant at 80f from a deep vacuum. It also didn't cool at ALL. The 1996 Civic system tested called for about 22-24oz. You're talking 12.5% of original system capacity. This is why you can never simply guess a diagnosis with MVAC systems. So the fact that you compressor is still running literally means nothing except there could be 2-3oz or the full 16oz in there.

Please don't spend money on a compressor just yet. I strongly believe you have a huge leak. And if you do replace it, replace the receiver drier at the same time and add oil PER THE SERVICE MANUAL. Oftentimes the OEM compressor is the best model to keep since some mentally defective person somehow rebuilds every aftermarket A/C compressor.

FOMULA91

iTrader: (3)

Thanks for the feedback holmesnmanny & sumdewd

My brother recovered 15.3 oz of refrigerant (Yesterday) so the system seems to have no leak after the refill last week. We also checked for leak via Dye/light in the dark with the garage shut for better result and that was on Wednesday night.

After the recovery and refill once again yesterday, the pressure gauge reads 15 PSI for Low pressure and 120-130 PSI for High pressure while the car is on idle and compressor kicking in.

holmesnmanny

how is the ac cooling right now ? is it working properly ?

i would suggest cleaning the condenser

sumdewd

What was the ambient temperature? This one has me a little confused right now. A weak compressor would make high/low pressures closer to the static PSI when it's running. You're pulling down on the low side but the high side isn't very far. (???) Is the recovery machine good and definitely putting 15.3 ounces in? On paper it looks like a low charge or it's really cold outside.

It's also possible that the expansion valve could be the culprit. I'm at work right now but now I wanna do some research later and get back to you. I mean I don't doubt your brother's expertise, but I'm personally just not sold on a new compressor just yet.

I don't know whether this car has a heater core reheating issue like the 88-00 Civics did. Their water valve would fail and passively run the heater at all times. You'd get good pressures but ****-tier cooling of the cabin.

FOMULA91

iTrader: (3)

The ambient temperature here in San Diego was around 78-82 F so the operating psi for a good compressor should perform around 40-50 PSI Low and 175-210 PSI High.

My brother works at the local Toyota dealer and they don't carry anything fancy but use standard equipment.

I mean, the given PSI # for both Low and High is way below standard which indicate the compressor is not doing its job...

Either way, my brother empty out the system again and we're preparing to replace the compressor, receiver drier, belt and o-ring.

Thanks again for your reply.

sumdewd

I'm still not convinced a weak compressor is the issue, but I hope it works out for you. I hope you hold onto the old one in case your replacement does not solve the issue. These compressors aren't variable displacement for this model year, and you said it worked fine after charging it.. Compressors don't magically heal themselves after adding more refrigerant. That would be like a heart failure patient being fine after a blood transfusion. I still think there's something else at play here.

Most A/C issues can be solved or at least diagnosed with a drain, proper evacuation, and fill to factory spec, which is going to happen regardless if you're replacing the compressor with a reputable shop.

Let us know what happens. I'm genuinely curious with this one. Holmesnmanny has stated more than once in the past that bad expansion valves plague this generation, and I'm definitely leaning in that direction at the moment.

FOMULA91

iTrader: (3)

Yes, I know right? I was pretty confuse myself since adding a can of refrigerant helped but completely fail couple days after my brother did the evacuation and fill to spec.

I searched about the expansion valves plague but that will usually provide cold air first then stop do to clogged valve. The low pressure line on this Civic doesn't even get cold nor show any sign of mist...

I mainly read a lot of people complaining about the clutch not turning on or it won't turn off but this isn't the case here. However, I did read a lot of people complaining about the compressor failing and replacing it...

I spoke my parent but they just told me that the A/C on the Civic never really had Ice cold breeze when they first bought the Civic from the dealer but never really complained since they hardly used it (only go out to buy grocery)...

holmesnmanny

I suppose it's possible the expansion valve is sticking partially open instead of sticking closed as normally is the case.

FOMULA91

iTrader: (3)

WOW didn't know holmesnmanny got banned...

Either way, I got my Denso ac compressor last week and installed it. I was thinking the OEM compressor was Denso too but it was actually Sanden...
After installation, my brother took it to the dealer (Saturday 08/11) to add Pag oil and charge refrigerant to spec.
Everything so far is working great.