Edit postDelete postReport this postReply with quote1998 Civic LX New AC Not Cold
by dsjacr on Sun Jul 17, 2011 12:46 pm

Hello,
This is my first post here and I appreciate any feedback.
Yesterday I installed a new and not remanufactured compressor, condensor, condensor fan, drier, expansion valve, o-rings, binary pressure switch & heater control valve since my old system went out and never blew that cold anyways. I was trying to eliminate problems and here I am now. The entire hose and evaporator core were completely flushed. I filled the compressor with 4 1/3 ounces of PAG oil and pulled a vaccum down to 29 for 1/2 hour. After 8 hours the system was still at 29, so definitely no leaks. I added the freon late last night and got the pressure at Low 30 and High 175 at idle. I drove it today and the vent temperature never got below 59 degrees. I pulled it back in the garage with the engine warm and at 91 outside and the engine at 1500 rpms the low is reading 23 and the high 250. I was told that the system requires 21-22 ounces and I put one whole 12 oz can and added another until I got the 30/175 at idle and a luke warm motor. The final can still has a little in it but not that much. What could possibly be wrong here? The low side line feels pretty cool to the touch. Thanks

 

Pressures look good. I suspect the heater is not turning off fully. Check that the heater valve on the firewall closes fully with the dash control on full cold.

Also when replacing the expansion valve you have to attach the sensor bulb properly to the side of the evaporator outlet line and insulate it from external heat.

 

I put the temperature probe into the metal hole that the old one came out of. It had a small wrap of insulation already around it. Would it be better to rewrap it with more insulation? Does the probe need to have any part of it exposed? I replaced the heater control valve since the old one felt hot on both sides of the controller. The new one feels the same way. It lookalike it is closing fully. I have even pushed it closed with my hand and it stops in the same position as the control know the puts it. Thanks

 

I don't know what is going on. I went out and rechecked the heater hose and it is only hot on the engine side now. I rechecked the pressure at idle and it is 34/210 at 94F and feels like 105F according to the weather channel. The high side needle is jumping back and forth a few lbs. I am at a loss now. Thanks for your responses.

 

90 F ambient temperature.

At idle and the AC off the low side is 55 and the high side is 175. With the ac on at idle the low side is 35 and the high side is 203. At 1500 rpms the low side is 21 and the high side is at 220. The ac will cool to 45 degrees while driving and back up to 55 at idle.

 

55 at idle is about all that mine will do too. Does the compressor cycle while driving? That would mean the evaporator is getting cold enough for the sensor to cycle it off.

 

I don't know how to tell if it is.cycling off and on while driving. I would assume so since it will cool more while at hwy speeds.

 

I don't know how to tell if it is.cycling off and on while driving. I would assume so since it will cool more while at hwy speeds.

 

Is the evaporator possibly clogged with gunk and not transferring heat efficiently? I noticed you didn't replace it.

 

That would be my luck. It flushed out clean but im not sure if it isn't the problem.