a/c warmer at highway speed ?????

[Explorer/Stang]

Hi, i have a 96 explorer. I replaced a/c compressor cause it was leaking oil. I Added specified oil. Also replaced orfice tube. I was going to charge myself but everyone says the air vacume pump is not good. So i took it to shop and had them charge it. They said it was all good. But when we drove in city, it was blowing 40. Thats great. But when we went on the highway it got about 8 to 10 degrees warmer and I can really feel the compressor cycling. (loss of power). Now my question is what Could Cause it to blow warmer on highway. I really need some ideas where to start. I really appreciate any help Thank you.

 

[ma96782]

Are you saying that the condition is: Temporary? Say air temps at 80 degrees F......you're at 40 degrees F when you're cruZing around town........but, about 50 degrees F when on the highway at highway speeds. Then, returns to 40 degrees F when you hit town again. Some, system temp fluctuations are normal.

It has been said before:

Check the air temp and compare it w/ the vent temp. At an air temp of 75-80 degrees F, you're looking for a 35-45 degrees F at the vent (about a 40 degree F difference, though close enough is good to).

Though, IF it's ONLY at hghway speeds...........I'd say take it back and complain. Give the shop the first chance to make it right.

IF you aren't comfortable with the shop having a chance at it. You could re-check system pressures and check (when it occurs) IF the lines aren't freezing (causing a temporary restriction).

BTW....you said in another thread:

Update: I removed the orfice tube and it was in the line like it got sucked out of its seat and was bent same as the pipe. I am getting the right one from ford = red with 2 o-rings.

So, I assume you got all of the old tube out and changed the orifice tube, to the factory recommended one? And, what about the pipe? You said, "bent same as the pipe."

Aloha, Mark

PS....Note what color orifice tube the site below says should be used for a '96 Explorer........you once said......

also the original orfice was brown with two o-rings and the new one was white with 1 o-ring. i appreciate any help.

http://autoacrepairs.com/ford_orifice_tube_application9202.htm

I checked the NAPA web site and they also said: Red. You should/could also double check with the FORD dealership, about what color orifice tube to use. Maybe you "thought" it was brown due to contamination/discoloration and age. Ford Red, hole size .062......vs.......Ford Brown, hole size .047

 

[Explorer/Stang]

Hi, At 85 Deg, Yes it blows 40 in city but cruising on highway it blows 50. The correct orfice tube is in there now. Bought it from ford. I cant see if the pipes at the accumulator is freezing up. I stopped & checked it as soon as i got off the highway and there was Alot of condinsation but no ice at all. I am going to put my gauges on to check pressures Hopefully today if i get the time. Yes it is red my fault it looked brown. What I meant (bent as the pipe) Where the orfice tube goes in the pipe the other pipe (Where it connects) has a slight bend in it and the orfice was in that pipe so it actually came out of its seat. Thank you I really appreciate your help.

 

[ma96782]

I went riding on the freeway today (60-65 MPH).......and the same thing that you saw, 50s on the freeway, happened to me. But, when I got back to cruZing in town it was back to the mid 40s.....so, I wouldn't worry about it. BTW, the freeway is concrete and there is no shade around.....I can only guess what the temps were.........and, it was hot. Then around town, shade trees and black top.........so, just by that I figure it's cooler in town. But, this is Washigton........the elec. sign in town said it was 73 degrees F..........I was at about 46 degrees F inside my car (not on max, 3rd speed on the fan).

My wife thinks I'm crazy....watching the temps on my digital thermoteter.....going up and down.....and it measures in the 1/10th of a degree.

Aloha, Mark

PS.....And, you could always check your pressures against the pressure/temp chart.

http://www.autoacforum.com/aacf/ptchart.cfm

 

[ma96782]

I noticed something else, today. When I have the fan speed set to the fastest speed (4) the temps will be higher, then when it's set at a lower speed (1)......the difference was about 20 degrees or more.

I guess it has something to do with the air staying next to the evaporator longer......thus, more time to loose heat.

Results

Set the AC (max), fan speed set at the fastest speed, doors closed and windows up, 10 mins. running to stabilize the system. Check the ambient air temp and compare it w/ the vent temp. At an ambient air temp of 75-80 degrees F, you're looking for a 35-45 degrees F at the vent (about a 40 degree F difference, though close enough is good to).

Ambient air temps are taken 2” in front of the condenser. Vent temp is taken at the dash vent closest to the evaporator (usually one of the center vents).


Aloha, Mark