Need A/C advice ASAP - very urgent

Moushka · **Joined:** Wed Jul 13, 2011 10:56 pm **Posts:** 2

Hey all, have on '05 with around 51000 miles. It's still covered under warranty and I'm having huge problems with A/C issues that has 2 different opinion by 2 mechanics and the warranty will only pay for the local dealership to do the work. Brought it in to them Jun 30th for a full check up before making a 850 mile trip (supposed to be on it right now). Told them A/C is NOT working and small pinion seal leak. After 12 hours they called said it was ready and A/C problem is in my head. After the long weekend still blowing hair dryer hot air on anything but 1 fan (which doesn't cool anything). Took it to a local mechanic who said there was no freon, did an e-vac and recharge. On test drive lost almost 1/2 charge. Noticeable damage to fan also noted. Recharged with dye to try to find leak. Did some work but warranty said they had to stop and had to be returned to dealership for further repair. Final recommendation is leak behind dash.
Work done:
A/C Compressor Hose Assembly vale Core
R&R CMPR Hose Assembly
Fan Clutch

Back at dealership-
Dropped off on Thurs Jul 7th and just got back today. Their diagnostics say it was a leak at the crimp in the A/C liquid line that was visibly noticed. Now, if It wasn't seen before and they had even added dye to try to identify the problem.
work they did:
Line - A/C liquid
Condenser suction and discharge
added refrigant

Again acted like I was crazy. Drove it home. Seemed like possibly a little cooler at first but was in a lot of traffic and started getting hot fast. Tried turning it up and air became blow dryer hot again. When on the highway was cooler than traffic but trust me, it was 102 outside and if anybody saw me when I got out they would have thought I'd been swimming.

I have to drive from South Texas to Alabama ASAP, movers already took my stuff 6 days ago. Can't do that drive with a 2 yr old in 100 + temps and only feel cooler with the windows down. Dealership agreed to meet me 1/2 hour before open tomorrow to check again. Thinking of trapping the service manager inside at 3 pm, windows up and a/c on high and see who's crazy!

WolverineFW · **Posted:** Thu Jul 14, 2011 12:42 am

They should be measuring the temperature of the discharge air coming from your vents and then calculating a temperature differential. If they are, they will have a hard number. If not...they are blowing smoke up your arse.

There are other ways to find leaks besides uv dye. Did the other mechanic even check to see if it held a vacuum when he recharged it?

papaindigo · **Posted:** Thu Jul 14, 2011 9:10 am

Actual cooling performance of the AC is easily checked with a simple household thermometer and the results are not subject to much debate. The standard test is outlined in both the 2005 and 2006 FSMs (copies available at http://colorado4wheel.com/manuals/Jeep/KJ/) on about page 24-4. To run the test get the KJ up to operating temp and fully cooled down. By full cooled down I mean run the AC on Max A/C-Recirculation with the fan on high for about 10 miles. If there is no significant drop in perfomance at "idle" (e.g. ca. 1,000 rpm) AND your system meets the temp differentials listed in the chart then it is functioning normally. If it does not meet or come close to meeting the temp differentials it is not functioning normally and needs an appropriate repair which is outside my area of expertise. Per the chart at an ambient outside temp of about 100 degrees F the AC vent temp should be about 55 degrees F. For what it's worth when I ran this test in June 2010 my readings were 45 and 48 at 75 and 95 ambient respectively which puts the lower reading right in line with the chart and the upper reading somewhat cooler than the chart indicates.

Wobbly · **Posted:** Thu Jul 14, 2011 9:21 am

"Took it to a local mechanic who said there was no freon, did an e-vac and recharge. "

If no leak testing was performed, this person should not be servicing air conditioning systems.

Sounds like the dealer might be replacing parts instead of diagnosing problems. At first impression it seems that they are trying to browbeat you into accepting a non-working system while possibly milking the warranty.

geordi · **Posted:** Thu Jul 14, 2011 9:49 am

In the local mechanic's defense, you can't really check for leaks if there isn't any coolant in the system to check with. At a local shop that I have been to in Florida, (and is VERY busy most of the time) their policy is to check / charge the system first, and look for leaks then with a chemical sniffer. The second option for places that might not have the business to justify a $$$$$ sniffer tool is to charge it up with the UV dye. Either way - Give the system something to leak out, then find that leak.

Oddly enough, my AC just recently started leaking BADLY, loses all the gas within 24 hours of charging. UV dye in the system was all over the top of the compressor at the hose ports, so it looks like just those hoses or o-rings is the problem for mine. The compressor works great, although oddly - it manages to make 225psi on the high side with only 12 ounces of R134, but the low side was 60psi at 95* ambient. With 2 cans of gas, the numbers were about the same. With only the one can (not enough gas) I would have expected a lower low side pressure. But it is still leaking, so I have to go back into the system and try again with better o-rings. What is annoying on mine, is that the thing held a 21" vacuum for about an hour without leaking down at all before I charged it up. I thought it was fixed. Grrr.

Maybe yours has the same leak, from the o-rings on the compressor? The dye will tell you.

Wobbly · **Posted:** Thu Jul 14, 2011 12:38 pm

"In the local mechanic's defense, you can't really check for leaks if there isn't any coolant in the system to check with."

System leaks can be tested with nitrogen. Some shops add some R-22 along with the nitrogen to sniff out leaks.

http://www.youtube.com/watch?v=sbveNeaz ... re=related

Moushka · **Joined:** Wed Jul 13, 2011 10:56 pm **Posts:** 2

SO, took it back today and still charged and finally not leaking. Made them get in and drive it and they were like "oh wow it's blowing hot air". But noticed that if going above 60mph it starts to cool again.
They did another "inspection" of the system and realized that the electrical wiring to the compressor was frayed. You'd think that having worked on this vehicle for almost 2 full weeks now somebody would have noticed bad wiring?
They also noticed that the fan is only coming on intermittently, which was my own originally analysis to begin with.
The problem now is the closest replacement parts are in Dallas and wouldn't be available to them until Mon/Tues of next week.
Sorry but I have to be in Alabama by Monday so it looks like I'll be driving, hopefully over 60mph the entire way.
On the plus side the dealership has graciously agreed to pay for the extra week I had to stay here in a hotel and covered the $1200 the warranty didn't cover. So we'll see if anybody in Alabama is better than here.

Joe Romas · **Posted:** Thu Jul 14, 2011 1:36 pm

The fan may be working normally. They used to run whenever the compressor was running but now they are controlled by the pressure in the system.
I thought I had a fan problem on my 00 XJ untill I figured this out :banghead:

geordi · **Posted:** Thu Jul 14, 2011 9:33 pm

To check the fan control (which is in the computer) open the engine relay box and pull either the high fan or low fan relay. The fan will then almost immediately start with the remaining relay (if it works) and run continuously. If (when) you plug the removed relay back in, the fan will momentarily accelerate to full speed... Then stop b/c the computer has told it to.

I didn't know about the nitrogen trick, I've thought about pressurizing it with just compressed air since I have a vacuum to re-dry the system from any humidity... But haven't done that. I think this next time I will, or use my dive tank air which is already hyper-dry air.

WolverineFW · **Posted:** Thu Jul 14, 2011 9:59 pm

geordi wrote:

In the local mechanic's defense, you can't really check for leaks if there isn't any coolant in the system to check with. At a local shop that I have been to in Florida, (and is VERY busy most of the time) their policy is to check / charge the system first, and look for leaks then with a chemical sniffer. The second option for places that might not have the business to justify a $$$$$ sniffer tool is to charge it up with the UV dye. Either way - Give the system something to leak out, then find that leak.

Not true. One method as you have noted is to use a refrigerant sniffer. Second as mentioned is the UV dye.

Another method to include as noted above is to use nitrogen....which should be dry nitrogen. You do not want to introduce any moisture and/or non-condensibles into the system at all. Do not use compressed air! Of course you need to use a proper pressure regulator and understand what the safe working pressure of your system is so that you do not overpressurize it.

Dry nitrogen is also used to break a vacuum on systems exposed to long periods of moisture.

Lastly, any system that is leaking will not hold a vacuum for any significant period of time. The only way to know for sure is by using a vacuum gauge that measures in microns.

dkenny · **Posted:** Thu Jul 14, 2011 10:23 pm

I would think 21" of vacuum is a poor vacuum..think 29" or more.

glad to hear the OP got some results. too bad it took so long for the dealer to find the problem

-dkenny

Need A/C advice ASAP - very urgent

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