WJCO's Build Thread, 1999 WJ

WJCO

Meme King
So here's an update. Picked up kids at school yesterday, sat in line for 30 minutes and decided not to turn on AC. It was 95F out and was miserable. Gauge never even rose, perfect temp on the gauge (probably 200-205). After 30 minutes with ambient temps of 95F, I knew if cooling system was acting up, it would have already. So I kicked on the AC.....

Not even 2 minutes later the gauge starts rising and I can hear compressor kicking on and off and AC wouldn't cool. So I shut it off. Later at home (still hot outside), I decided to bypass the low pressure switch and high pressure switch (one at a time) just to see if that would keep the clutch running long enough to see if AC would cool or if coolant temp would stay constant. With the high pressure switch bypassed, engine ran for maybe 10 seconds and pressure relief valve on compressor popped spewing out R134A. So I KNOW my high side pressure is too high on a hot day.

This morning I checked the AC system again (75F out). Everything worked PERFECT. Vent temps in the high 30s, clutch stays running, cooling system temps never rise. All the high side lines were warm to the touch (100ish), low side lines were all cold and lightly condensating, even at the orifice tube, I could feel where the line went from hot to cool like it should.

Any ideas? And yes fans are working normally and condensor looks clean to me. Fans even work when the issue occurs. I can put an object on one side and see it clearly while looking through the fins. (Yes I know I need to get a set of gauges and diag this thing while it's acting up).
 
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BaddestCross

Active Member
So here's an update. Picked up kids at school yesterday, sat in line for 30 minutes and decided not to turn on AC. It was 95F out and was miserable. Gauge never even rose, perfect temp on the gauge (probably 200-205). After 30 minutes with ambient temps of 95F, I knew if cooling system was acting up, it would have already. So I kicked on the AC.....

Not even 2 minutes later the gauge starts rising and I can hear compressor kicking on and off and AC wouldn't cool. So I shut it off. Later at home (still hot outside), I decided to bypass the low pressure switch and high pressure switch (one at a time) just to see if that would keep the clutch running long enough to see if AC would cool or if coolant temp would stay constant. With the high pressure switch bypassed, engine ran for maybe 10 seconds and pressure relief valve on compressor popped spewing out R134A. So I KNOW my high side pressure is too high on a hot day.

This morning I checked the AC system again (75F out). Everything worked PERFECT. Vent temps in the high 30s, clutch stays running, cooling system temps never rise. All the high side lines were warm to the touch (100ish), low side lines were all cold and lightly condensating, even at the orifice tube, I could feel where the line went from hot to cool like it should.

Any ideas? And yes fans are working normally and condensor looks clean to me. Fans even work when the issue occurs. I can put an object on one side and see it clearly while looking through the fins. (Yes I know I need to get a set of gauges and diag this thing while it's acting up).
If this was a residential AC, I'd say it was a dirty condenser, bad fan motor, TXV/piston issue, or plugged liquid line filter but I don't know how auto ACs work...

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407
 

BananaJeep

Caught the Bug
7885b9c591e463719efaa63c3e6ab82b.jpg
 

WJCO

Meme King
If this was a residential AC, I'd say it was a dirty condenser, bad fan motor, TXV/piston issue, or plugged liquid line filter but I don't know how auto ACs work...

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407

Condensor looks clean(and I've sprayed it out about 4 times now from the inside outward), fan motor new (also has a mechanical fan that works fine). No TXV (orifice tube is the metering device). The orifice tube is in the liquid line between the condensor and the evap core, this is where the refrigerant changes from a high pressure liquid to a low pressure liquid prior to entering the evaporator. This morning with system working normally, on the high side the line was warm to the touch (about as warm as the condensor outlet, 90ish), but then feeling the low side after the orifice tube it was nice and cold (probably 45-50), so I really think that is working properly.
 

BaddestCross

Active Member
Condensor looks clean(and I've sprayed it out about 4 times now from the inside outward), fan motor new (also has a mechanical fan that works fine). No TXV (orifice tube is the metering device). The orifice tube is in the liquid line between the condensor and the evap core, this is where the refrigerant changes from a high pressure liquid to a low pressure liquid prior to entering the evaporator. This morning with system working normally, on the high side the line was warm to the touch (about as warm as the condensor outlet, 90ish), but then feeling the low side after the orifice tube it was nice and cold (probably 45-50), so I really think that is working properly.
Okay. So, forgetting about the difference in how the auto and residential AC accomplishes the same goal, the only thing that causes high pressure is either a blockage in the refrigerant lines, or the inability of the condenser to remove heat.

The capillary tube isn't bent and you didn't alter the length of it, I'm assuming, so that can be eliminated unless something got through the filter and partially plugged it. I'm assuming there are filters somewhere in the lines, so they may be getting plugged up. You would definitely need a set of gauges to help troubleshoot.

You seem to be sure about the condenser coil being clean and the fan operating properly, so those can probably be eliminated.

At this point, I would probably evacuate and recharge the refrigerant system. If there are filters that can be replaced, I'd probably do that as well.

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407
 

longarmwj

New member
Like BaddestCross said, I don't have any idea how automotive AC systems work. All I know is my JKs AC is ice cold, and my WJ has none :cheesy:
 

WJCO

Meme King
Okay. So, forgetting about the difference in how the auto and residential AC accomplishes the same goal, the only thing that causes high pressure is either a blockage in the refrigerant lines, or the inability of the condenser to remove heat.

The capillary tube isn't bent and you didn't alter the length of it, I'm assuming, so that can be eliminated unless something got through the filter and partially plugged it. I'm assuming there are filters somewhere in the lines, so they may be getting plugged up. You would definitely need a set of gauges to help troubleshoot.

You seem to be sure about the condenser coil being clean and the fan operating properly, so those can probably be eliminated.

At this point, I would probably evacuate and recharge the refrigerant system. If there are filters that can be replaced, I'd probably do that as well.

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407

The orifice tube itself is a filter, it not only meters the refrigerant but has a screen filter as well. The only time these get restricted is when compressors fail and send metal through the system, while that may be the case, it's unlikely, no noise from compressor and AC works fine until it's really hot out. No other filters that I know of. I'm going to visually inspect the condensor a little more for any damage or bends at the tubes but so far haven't seen any. I will likely just buy a set of gauges in the next year as well to really see what's going on. Orifice tube (pain in the ass to get to, have to replace line or cut line and add one with a splice kit):

A5100_GMOrificeTube.jpg
 

WJCO

Meme King
Like BaddestCross said, I don't have any idea how automotive AC systems work. All I know is my JKs AC is ice cold, and my WJ has none :cheesy:

Lol. I may be soon following that path on the WJ. I don't want to throw parts at it, but my gut feeling is it's the condensor. That's an expensive and time-consuming part to gamble on.
 

BaddestCross

Active Member
Lol. I may be soon following that path on the WJ. I don't want to throw parts at it, but my gut feeling is it's the condensor. That's an expensive and time-consuming part to gamble on.
Everything else considered, you're probably headed in the right direction. A cheap next step would be to evacuate the system and pull a good vacuum to make sure there aren't any non-condensables in the system, recharge it and see if it still acts up.

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407
 

WJCO

Meme King
Everything else considered, you're probably headed in the right direction. A cheap next step would be to evacuate the system and pull a good vacuum to make sure there aren't any non-condensables in the system, recharge it and see if it still acts up.

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407

With the cost of a vacuum pump and gauges, I may just have a shop do that, lol. I would have to take it to them regardless to capture the refrigerant.
 

WJCO

Meme King
Yeah, I figured if you didn't have gauges that you wouldn't have a pump. I just meant that shouldn't be a huge cost to have the service done. 👍

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407

Could you rent a vacuum pump from a local auto parts store? I did this several years back, but I don't know if you can still rent them.

Sent from my VS990 using WAYALIFE mobile app

Harbor freight has them for like 20 bucks, so that's no big deal, but a shop will do an evacuation and recharge properly and legally and a pressure check for about 100 bucks. To me, it's worth paying the shop to do the whole thing on something like that compared to buying the tools myself.
 

BaddestCross

Active Member
Harbor freight has them for like 20 bucks, so that's no big deal, but a shop will do an evacuation and recharge properly and legally and a pressure check for about 100 bucks. To me, it's worth paying the shop to do the whole thing on something like that compared to buying the tools myself.
Agreed. And they'll probably be able to tell if there's a problem with the condenser at the same time.

I just hope you can put this overheating issue to bed soon. It's got to be frustrating for you.

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407
 

cozdude

Guy with a Red 2-Door
Stop being cheap and buy some gauges already! :cheesy:

Seriously tho, it does still sound like the condenser is internally clogged like I said the other day, especially since it's cycling so much. Hope you figure it out
 

WJCO

Meme King
Stop being cheap and buy some gauges already! :cheesy:

Seriously tho, it does still sound like the condenser is internally clogged like I said the other day, especially since it's cycling so much. Hope you figure it out

I hope I get this thing figured out too. Yesterday, I ran into a tech I used to work with and I trust him. We had a long talk and the Jeep was with me for him to look at. He use to work a at a Jeep dealer and knows these systems fairly well. His gut feeling is the radiator but sees the condensor being a possibility too, especially when I told him that it blew refrigerant out when I bypassed the high-pressure switch. He's doing some research now and we may just do an evac and recharge at his shop just for preventative to see where we're at.

He thinks if it's the radiator, it's likely on the end of it's life or just plugged enough to operate cooling system, then on a hot day, the heat from the condensor puts the radiator out of it's capability and all these symptoms occur, the radiator then gets hotter which makes the condensor hotter (next to each other) thus increasing the AC pressures and both systems start acting up. The only thing leading him away from the condensor is that AC cools fine when it's not as hot outside, no issues at all. He also finds the whole thing very strange that when revving up the engine, all issues go away and everything is fine. Driving me nuts! Both parts are not cheap and very labor intensive, that part sucks too.

Here's a pic I found online of basically what needs to be removed to do either (the radiator saves a few steps), along with a winch, grill guard, and lights on mine. :grayno:

IMG-20121111-00343.jpg
 
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cozdude

Guy with a Red 2-Door
I hope I get this thing figured out too. Yesterday, I ran into a tech I used to work with and I trust him. We had a long talk and the Jeep was with me for him to look at. He use to work a at a Jeep dealer and knows these systems fairly well. His gut feeling is the radiator but sees the condensor being a possibility too, especially when I told him that it blew refrigerant out when I bypassed the high-pressure switch. He's doing some research now and we may just do an evac and recharge at his shop just for preventative to see where we're at.

He thinks if it's the radiator, it's likely on the end of it's life or just plugged enough to operate cooling system, then on a hot day, the heat from the condensor puts the radiator out of it's capability and all these symptoms occur, the radiator then gets hotter which makes the condensor hotter (next to each other) thus increasing the AC pressures and both systems start acting up. The only thing leading him away from the condensor is that AC cools fine when it's not as hot outside, no issues at all. He also finds the whole thing very strange that when revving up the engine, all issues go away and everything is fine. Driving me nuts! Both parts are not cheap and very labor intensive, that part sucks too.

That does seem very logical and could be a possibility. Curious to see how it turns out
 

Stotch

Caught the Bug
Here's a pic I found online of basically what needs to be removed to do either (the radiator saves a few steps), along with a winch, grill guard, and lights on mine. :grayno:

:shock: Yikes, looks like you may have your work cut out for you there. Like you haven't worked hard enough on this issue already! :crazyeyes:

I hope you get this all worked out; unfortunately the most help I can be is to say: Good luck! :thumb:
 
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