98 xj Air conditioning problem

My 98 xj air conditioning system is working but not blowing enough cold air. Here is what I KNOW... compressor is working and not cycling, system is full of r-134a, low end inlet tube is frosting up by the evaporator inlet. We think there is a clog in the system somewhere, but connot find any expansion valve in this system! The 97 and earlier models have them, and my manual says nothing about this part being included in the 98 and later models. Any help would be appreciated as 100 degree + days here in AZ are a killer when your air doesn't work properly!

Your problem sound familiar for your model year. Read THIS LINK to see if it relates to your problem...

Ivan

jp's xj said:

system is full of r-134a

Click to expand...

I gather you've hooked up a gauge and tested the pressure as per instructions? Cause when mine did that it turned out to be low on freon.

Not the low pressure switch, I am not getteing enough cold air all the time, not just at start up. System is full of freon, low end inlet tube frosts up bad but outlet to accumulator tube stays warm. Evap core plugged??

Need more info......
How do you know your system is FULL of freon ? Did you have gauges connected to check LOW and HI side system pressures?
When you say not blowing enough cold air..... What quantity of air do you get coming from the vents on the different fan speeds and what temperature is it?
On the 97+ XJs there is a LPS (Low Pressure Switch) and a evaporator TX (temperature transducer) which control the cycling of the compressor thru the ECM.

Charles

I guess I was low on freon, I put in a 19 oz can and she is working fine again, although I'm not sure where the leak off of old freon went!! One thing I noticed is a squeel from the belt when air is first turned on, the belt is good and not loose.

Alot of XJ and ZJ's have leaks in the evaporators, they are inside the heater box behind the dash. By now you also have air in the system and at this point it may not take anymore R134a. What I did was take it to a shop owned by a friend and customer and he evacuated the system, kept the vac on for 30 min and it held. We then recharged it only this time with R134a with a dye in it. Worked find for a couple of weeks but then started blowing warm air again, no leak evident using black light and goggles. I added two more cans of Dupont R134a and ran that for a couple of weeks and we checked again. This time the yellow dye showed up at the end of the drain thats on the passenger side firewall right above the frame rail. Evaporator is leaking, cost is about $700 for replacment, ~$300 for the evap and the rest is labor because the whole dash has to come out to remove the old one and install the new one. 97 XJ's were covered under a recall but not 98's even though mine was manufactured in Oct 97...

Did you throw in 19 ounces of R134 based on some measurements with a pressure gauge, or some other method?

I ask because it IS possible to OVERFILL the system, too. If that happens, a worst case scenario would be a trashed compressor.

I will say the same warning I have repeated before--if you do not have the right tools, DO NOT start messing with your AC system. You can actually make the problem WORSE, and cost yourself BIG MONEY to get it repaired. This is one area that I recommend amateur mechanics leave alone, unless they are equipped with the right tools.

Just a word to the wise. I leave in the Phoenix area, too, so I KNOW how important good AC is!!!!

If the system was putting out a little cool air then the system is still under pressure when the system is off. When the system is running the LPS will shut off the compressor before the evaporator freezes up and system pressure drops below atmospheric pressure....
With this said.... the system could not have drawn air into the closed system.
Adding 19oz of R-134a into the system with out the use of gauges and a temperature probe can be VERY dangerous (like AZJeff said) to you and your system.... If the system is OVERFILLED you risk the chance of the compressor taking in liquid refrigerant to the suction side which will cause the compressor to lock up (liquid will not compress) and destroy the compressor and possibly hurt you when parts start flying.
Depending upon the outside air temperature going thru the evaporator coils the suction pressure should be approximately 38#.
The squealing sound you hear when you first start the a/c is when the compressor starts turning and tries to overcome system pressure that can be more than 100# on a hot day.
Hope this clears up a any questions.

Charles

it is normal to loose around 4-6 oz or 134 a year

brianb2247 said:

it is normal to loose around 4-6 oz or 134 a year

Click to expand...

You shouldn't lose any. Ever. If you do, then you've got a leak somewhere.

Kyung

[/QUOTE] 97 XJ's were covered under a recall but not 98's even though mine was manufactured in Oct 97...[/QUOTE]


I never heard of a recall for this for the 97s. I have a 97 with a bad evap. When was the recall issued? How do you check for recalls?

One thing I noticed is a squeel from the belt when air is first turned on, the belt is good and not loose.

Click to expand...

Good sign that system is over full and liquid is getting back to the compressor.

Might want to read this.
http://auto.consumerguide.com/Auto/.../2359/act/usedcarreviewreliability?print=yes/
I found it on alldata but they make finding them harder now with out paying..

Anybod know if there is a central recall tsb site thats not trying to squeeze money out of you..

I found this site. I'm not sure how up to date it is though.

http://www.autosafety.org/autodefects/JEEP.htm

Try this site. It seems very current.

http://www-odi.nhtsa.dot.gov/cars/problems/recalls/results.cfm

Still nothing about A/C evap. though...