A/C performance troubleshooting - need help please!

[tsitalon1]

Hey guys,

Just moved to Texas and my A/C is not up to snuff.

Short story:
Replaced compressor
Dryer
Expansion Valve
Cleaned Evaporator and housing
Replaced all o-rings
Had A/C shop flush and fill
Heater core bypass
A/F fan resistor bypassed (fan on high when on)

Long story:
clicky

Current gauge readings at 80º ambient:

26-30 Low / 210-225 High
Slight bubbles in sight glass

At 80º ambient, I'm getting 45-50º outlet temps.
At 95º ambient, I'm getting 60-65º outlet temps.

Evap inlet line starts to get hot around 90º ambient and I feel the passenger side of condenser getting hot (115º)
Evap outlet line is very cold and condensation is dripping off the pipe.

Using water to cool down the condenser will make outlet temps drop from 60º to 43º.

I'm inclined to replace the condenser, but I'm not sure if just adding a 7" fan to the passenger side would help instead.

What are your guys thoughts on all the above?

 

[marvinmadman]

What are your Hi/Lo pressures and outlet temps while cruising at 55 mph VS parked while reved up to say 3k for 30-60 seconds?

 

[tsitalon1]

LMAO - How would I obtain my pressures while driving down the road at 55mph?

Outlet temps don't really change much whether stationary or moving. The lowest I was able to get was 43º while spraying water on my condenser at 80º ambient temps

The presence of bubbles in the slight glass make me want to add freon, but the pressures are already spot on i think. - If I could just get it to drop another 10º, I'd be happy!

 

[marvinmadman]

Easy. Route the gauges under the hood and place them under the wiper.

 

[marvinmadman]

If cruising doesn't help outlet temps, throw this thought out the window.

Quoting tsitalon1:

I'm not sure if just adding a 7" fan to the passenger side would help instead.

 

[tsitalon1]

Good point - Guess I could. What are we looking for exactly?

I"m assuming the condenser temps should drop a little, but not much since I still have the stock IC blocking half of the damn condenser.

So I should see pressure drop a bit right?

 

[marvinmadman]

I had a similar problem before. Not saying your system is overcharged, but its possible. On converted systems I usually end up with about 75% recommended charge. But if I have problems I would start with 50% charge and see if the low side dips too low while cruising and add freon if needed. That particular car "90 civic sedan" ended up with 1 can and worked perfect. Low side would go as low as 5 psi and outlet temps were cold as 40º.


EDIT ERRRRRR I read the other thread wrong. I thought you put in 33oz of freon. <img src="/ubbthreads/images/graemlins/crazy.gif" alt="" />

 

[tsitalon1]

It has since been charged by an A/C shop...

Overcharged wouldn't show bubbles would it?

 

[marvinmadman]

I believe the r134a systems tend to not put sight glasses because the oil foams up. Sounds like your condensor isn't up to the task or overcharged with freon or OIL. Too much oil would raise pressure and negate efficiency. Many variables /ubbthreads/images/graemlins/uhh.gif

 

[marvinmadman]

Did you thoroughly clean the system of old oil when you added the PAG?

 

[tsitalon1]

Yep, had the shop flush before charging.

 

[tsitalon1]

Quoting marvinmadman:
I believe the r134a systems tend to not put sight glasses because the oil foams up. Sounds like your condensor isn't up to the task or overcharged with freon or OIL. Too much oil would raise pressure and negate efficiency. Many variables /ubbthreads/images/graemlins/uhh.gif



Compressor should be fine since the pressures are 30/220 right?

 

[galant651]

220 seems a little bit high but is reasonable, 30 on the low side is actually really being ambiant temp in 80. i would say its more of a cooling problem in the condensor, not that the condensor is bad but theres not enough airflow at idle to reallly cool it.

 

[galant651]

what are your high and low side readings when its been sitting and has equalized?

 

[tsitalon1]

Are you asking what the pressures are after shutting off the car and waiting 30 minutes?

I'll have to try that. what will that tell us?

 

[galant651]

it can help tell you if it was overcharged. how many ounces is it suppose to be charged with?

 

[tsitalon1]

Label on the hood lists 33oz total, though I'm not sure if that's a listing for r12 or r134a. My understanding is this should be oil and freon.

 

[galant651]

oil and freon should be 2 different values. and charge amount wont really vary much between r12 or r134. its just a more "economical" freon. does it give you a value for oil and freon or only a total?

 

[marvinmadman]

If you can see light through all 3 you should have good airflow.

Sideways pic FTL

 

[tsitalon1]

Quick update.

I decided to add a smidgen more freon. I was carefull not to add *too much** and the gauge readings only moved a few PSI.

Currently I am able to maintain 43º oulet temps, even at 95º ambient temps, but only with the blower on 2 (second lowest setting). If I set the blower to high, the temps raise to 50-52º

I've ordered a 7" slim fan to put on the pass side of the condenser and hope to get it even better. I will also remove the radiator and backflush the condenser with some degreaser.

I'll update the thread soon