While driving down road my 97 xj6 vdp, the a/c compressor for air conditioning system starts venting gas R134 refrigerant, then stops. Air con no worked now. I added some R134 to the low side port and got pressure out of red and just in to green and ac compressor safety relief valve pops open again, starts releasing gas for a second or two, then closes again. I put some UV leak detector in, and then added gas again REAL Slowly. As soon as gauge was to almost green safety valve vents again and closes, leaving ac system pressurized but low on the gauge in red. That Night I used the UV light and yellow glasses to look for leaks, but didn't see any. (I know leaking doesn't seem to be the problem, but just wanted to check). Coincidentally I had a similar problem In my Hyundai 2 months ago, compressor would vent gas when car was idling in the hot Florida sun for a while, but compressor turned out to be fine, cause was found to be1 of 2 radiator fans failing to come on, due to a intermittent fan relay. Solved the problem for $20 bucks. So, I'm Trying to avoid going to the jag shop, and wondered, is there anything "commonly known" that what might cause the air con compressor to release some gas and close again like that?

 

I don't know either, but I had the same thing happen on my 1994 XJ12(XJ81) a few weeks ago and just haven't spent any time looking into why. So it will be interesting to hear the suggestions.

AFAIK, my fans are working fine.

I wonder if these DIY quick-charge kits from the parts store just aren't accurate enough in some cases and over-charge the system.

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sounds like an overcharge,however might be restriction in system

 

Well, I've owned this car for 6 years, and have never added refirgerant. The a/c has always been great, and I'm in south florida. I have a (NEW) set of manifold guages and will check pressures on high and low. but I may be athe mercy of an a/c shop, throwing parts at it unitl it works or I run out of money! So restriciton is logical, where might thoes be? Receiver drier, or some cut off valve or what have you?

 

Well, that's interesting, no really. My Red XJ6 has been filled once since I took the compressor off and replaced all seals. Just stopped working last fall. So left it to be done this summer. Pressure had dropped real low but the compressor still locked in and run, but no cold.

Took it to a friends garage and he topped it up saying it was very low. Got to pressure but not very cold. He told me he added a couple of pounds more (should have known better) well it lasted three miles and no cold.

Looked at it the following day noticed that compressor was running and both hoses very hot. Then, it vented out a lot of gas and oil. Still engages compressor but gets so hot water sprayed on the compressor turns instantly to steam. I suspect a blockage in the expansion valve. Dash out job I expect.

 

Would that really be a "dash out" job? I ask because at least on the XJ40 the expansion valve is in the engine bay and quite accessible. Is it under the dash on the X300?

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Yes Al the old XJ40 was nicely on the bulkhead but this lot is buried and is about the last thing to come out before you roll the body off to the scrappers. I was sure I'd taken this out from the last one I dismantled but heck can I find it. New exchanger isn't to wallet breaking and drier and other bits aren't to frightening. Partsmonkey I think.


I was hoping I was wrong and could coax the bits out by back feeding. But that's wishing for a miracle.

 

OK 3 questions.

1. Is there a test to see if expansion valve is actually clogged?
2. I am hoping the exchanger and expansion valve are on the right side behind right hand part glove box, so, does any one have links videos etc. remove dashboard out of 95-97 ( or close) for an XJ6 x300 ?
3. Would mean only the mid to right section needs to be removed?

 

Follow the a/c Hose's to the bulkhead, thats exacly where it is.

 

Ok I see where the a/c hoses enter the bulkhead firewall, and the valve is right behind that, so looks like right side of dash has to come out to got to the expansion valve. Thanks!

 

Vick trader
No Vic it isn't right behind the hoses, it's buried deep within the heater system. Look on ebay for an A?C evaporator and you'll see it's the bits on the left of the picture....I believe

https://www.ebay.com/itm/New-Air-Pro...97.m4902.l9144

There is a very good guide on here for removing the dashboard.

 

First, Thanks, The dash out guide and ebay info was excellent. I was bummed that I may have to do that (or worse pay for it to be done). I bought some a/c gauges, got a laser temperature gun, watched many you tube vids on diagnosing a/c issues with those tools. Today, I may have diagnosed the cause to be electric radiator fans, and may not have to take out the dash after all.in The pics attached you can see the high side pressure WAY up, yet both fans were off. High side gauge got up to 400 psi at one point. The temp at the high side port connector was 190-200 degrees Fahrenheit, Low side connector about 100deg. F (ambient temp 94 deg F.). I switched off the engine before the safety valve popped open again. THEN, the lower left side fan came on ! I restarted the car, the high side pressure dropped very fast to normal range. Then 2nd higher right side fan also came on for 1st time in 30 min of idling with a/c on. About time! Well then, that fan started squealing (bad bearing I'm sure). Fans will be replaced immediately, but, that's not solving the cause. My question is, how can I "hot wire" or force the fans on earlier, or find and fix the real cause of fans not showing up to work on time?


High side pressure kept climbing to 400 psi no fans would come on.


High side Valve got too hot to touch


Turn engine off, THEN lower left fan comes on ! High side pressure drops very fast to safe zone.


start car again and now both fans decide to come on. top right fan squeals off and on, bad bearing I'm sure.

My question is, how can I "hot wire" or force the fans on earlier, or, find and fix the real cause of fans not coming on when clearly needed?

 

I have seen where you can test / jumper the plug on the trinary pressure switch to make the fans come on high -- I believe -- this post says it will cause "both" fans to come on, but I did this last year to cause the fans go to high.
Not sure if this is the post showing the wires to test-jumper for high-speed because it's from April 2018 and I thought I did this in 2017.