Automotive Air Conditioning Information Forum (Archives)

jackhild on Sun August 07, 2011 4:35 PM

Year: 2002
Make: Mazda
Model: 626
Engine Size: 2.0
Refrigerant Type: 134a
Ambient Temp: 105
Pressure Low: 42
Pressure High: 225
Country of Origin: United States

I need a little information and assistance on this car.

Doesn't cool down quickly; Center vent temp on recirc. when it is cool on the highway is about 52-54*.

At idle, pressures 42/225. Center vent recirc temp =66*

at 2000 rpm, pressure 30/350. center vent recir temp=60*

Both fans running on high speed. Low pressure returning to compressor is cold and sweating, accumulator is cold and sweating.

Measurements taken after vacuum /recharge w/24oz of R134a. Spec is 26 oz, so techically I am a little undercharged, but 24 oz is easy with 12 oz cans.

High side restriction? Does this car an expansion valve or an orifice tube?

Could I have a faulty heater valve leaking through?

Thanks in advance.

Jack



Edited: Sun August 07, 2011 at 4:50 PM by jackhild

TRB on Sun August 07, 2011 10:24 PM

Orifice tube.

350 is getting up there at high idle and would make it hard for the system to cool. Might consider reclaiming refrigerant pulling a proper vacuum and charging back to the 26 ounces.

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bohica2xo on Mon August 08, 2011 12:28 AM

Clean the air side of the condensor.

Even a city car here in the desert collects plenty of small bugs, dirt & grime over 8 or 9 years. In the southeast, it can be much worse. That PF condensor has pretty tight fin spacing, and even if the surface is clean you can have a lot of trash packed in the fins. Use a strong surfactant like Simple Green or Zep Orange. Spray it full strength into the fins on a cold condensor & let it soak for a few minutes. Flush it out with a hose. Repeat.

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"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

jackhild on Mon August 08, 2011 8:08 AM

I found a very grimy Orifice tube. No trash or metal shavings, just black grime. I couldn't find a new one locally on Sunday afternoon. Mineral spirits, lacquer thinner, brake cleaner wouldn't clean it. Electrical contact cleaner finally did.

Is i t possible the condenser has that same goo inside, reducing the capacity? Can condensers be flushed?

I vacuumed recharged and pressures are better, cooling is slightly better at idle.

I intend to replace the orifice tube and the accumulator drier. I will clean the condenser fins.

Any other suggestions?

thx

Jack

JJM on Mon August 08, 2011 10:21 PM

If the OT has that kind of grime that didn't come off all that easily with light solvents, that stuff is in your condenser too. Probably the reason your high side pressures are so high.

Good news is it sounds like it might be flushable, but you'll need professional HECAT equipment to do it. Probably better off replacing the condenser, along with the other items you mentioned.

Joe

HECAT on Tue August 09, 2011 10:01 AM

With no service history other than a recharge; seems you have found burnt oil residues. Nice test you did to show that the generic petroleum distillate solvents that we often grab to clean oily residues; are not the right solvents to dissolve the synthetic refrigerant oils and their residues. The electrical contact cleaner probably contained 134a or another HFC and that is why it worked.



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jackhild on Sat August 13, 2011 8:58 AM

What do you think about installing a universal high-side filter, such as 13128TSI in the ACKITS store? Any benefit?