AC or belt?

Xodius · **Posted:** Sun May 17, 2009 8:59 pm

So over the past...oh few days I have noticed that my AC goes from cold to cool to cold and back again. I have also noticed that when I have my AC on the engine is running rougher...it sounds like the oil pressure shoots way up. Then it will quiet down again. Usually I only have this noise in the winter right when I start up my KJ then it goes away.

Today at a nice cool 104 I decided...well my wife did, that I need to recharge my AC, lol. So we picked up a few things that were needed anyway and a can with gauge. I hook up the gauge and see the pressures are high on the low end. I also notice that my AC clutch keeps engaging and disengaging about every 5 seconds or so. This I would assume is why it sounds rougher than normal.

My question for you is, how screwed am I? LOL. I mean do I just need a new belt and tensioner or do you think I need a whole new compressor?

FYI, I have roughly 98880 miles on my KJ.

Xodius · **Posted:** Sun May 17, 2009 9:28 pm

Also do you know if we can or need to jump the switch to find out if it is low on R134a?

Any help would be appreciated.

Thanks all.
Xod

tjkoen01 · **Posted:** Mon May 18, 2009 8:18 am

short cycling like that typically means you are low on refrigerant. only way to tell is if you hook up a set of gages and check the high and low side pressure.

Xodius · **Posted:** Mon May 18, 2009 11:25 am

OK, will swing by the parts store and pick up a high end gauge.

The low end gauge that came with the 134a, when I hooked that one up it went past the red and actually hit the needle stop back near zero. I quickly pulled it thinking DOH!

I will post the results tonight when I get off work.

Thanks TJKoen01.

Xodius · **Posted:** Mon May 18, 2009 7:59 pm

I talked to a Jeep tech and he said to just add the can of 134a. I am a bit hesitant as I could just imagine the sucker exploding in my hand.

On a separate note, anyone have an issue where when you start driving your engine sounds like it has a ton of oil pressure? I keep checking it and all looks good but it is a bit on the loud side from time to time.

tjkoen01 · **Posted:** Mon May 18, 2009 9:21 pm

Xodius wrote:

I talked to a Jeep tech and he said to just add the can of 134a. I am a bit hesitant as I could just imagine the sucker exploding in my hand.

On a separate note, anyone have an issue where when you start driving your engine sounds like it has a ton of oil pressure? I keep checking it and all looks good but it is a bit on the loud side from time to time.

i don't know what an engine sounds like with a lot of oil pressure...but i do know what it sounds like with not enough :shock:

chances are you can put a can in and it would help and you wouldn't damage anything. i just like to know what the high side is doing when charging a system.

tjkj2002 · **Posted:** Mon May 18, 2009 11:26 pm

To much R134A in your system will allow liquid refrigerant to get to the compressor and it will lock up and might take the serp belt with it.Better to have the correct people with the correct equipment to make sure the correct amount of R134A gets put into your system.

Have had a rash of "DIY'ers" that attempted to recharge there own systems come in after failing or damaging there systems since the temps have gotten higher.

Xodius · **Posted:** Mon May 18, 2009 11:46 pm

Well I talked to a few more mechanics and they said I should put a can of 134a in. I did and as I was hooking up the can some gas escaped but it was not cold. I added the full 18onz can and the ac is now running better. The clutch is not engaging and disengaging and the oil pressure noise went away *shrug*. I tried the gauge one more time and the pressure is sitting at about 45psi which is still low considering it was 99 out when I did this. I am guessing that perhaps I was near empty on 134a. Just a guess though. I am going to pick up one more small can and might add it tomorrow after I test a few mroe things. I will keep you posted.

tjkj2002 · **Posted:** Tue May 19, 2009 12:42 am

The correct amount of R134A for a '02 3.7 KJ is 1.63lbs.If you've added 18oz already you have got a leak that will just continue to leak until fixed.

tjkoen01 · **Posted:** Tue May 19, 2009 10:12 am

adding a can here and there will get you by for a while. usually the leaks get worse and eventually you'll have to get the leak fixed anyhow. my '96 zj started off needing to be topped off once a month.....after a couple months, it would leak out over night. if you want cold air, the moral of the story is get it fixed asap. it is cheaper in the long run.

oh yeah, don't bother with the leak stop stuff.....doesn't work.

Xodius · **Posted:** Tue May 19, 2009 11:24 am

hehe, will do. I did notice today while coming in I did not have that oil pressure noise either so I am thinking it is all in the AC arena. I guess 99,000 miles and 7 years before looking at the AC is a good thing.

jnaut · **Posted:** Tue May 19, 2009 3:55 pm

tjkj2002 wrote:

To much R134A in your system will allow liquid refrigerant to get to the compressor and it will lock up and might take the serp belt with it.Better to have the correct people with the correct equipment to make sure the correct amount of R134A gets put into your system.

Have had a rash of "DIY'ers" that attempted to recharge there own systems come in after failing or damaging there systems since the temps have gotten higher.

X2, air conditioning systems are not something the home user can really do, despite the proliferation of kits out there. You can check the pressure, and if it's low you *might* add some yourself... but remember, it's a closed system. Meaning if you're low on pressure, you're low on pressure for a reason which means you probably have a leak.

Had an air-conditioning tech once tell me in no uncertain terms: if your system is sound and has no leaks, it should *never* need to be recharged.

Check your air temps. Even when I suspected mine wasn't as cold as it should have been, my temp consistently read about 38*f.

Xodius · **Posted:** Tue May 19, 2009 6:04 pm

I just made a run to the local Lowes and it ran good. I did pop the hood and double check everything one more time. I did notice something that I did not before. The cap that goes on the low pressure port, there is a washer or something like that inside, it was all chewed up and actually went flying when I took off the cap. I am wondering if that could have been the issue...if the seal was off just enough to hit the valve stem.
Anyone know if that piece is really needed? Would that be the issue?

jnaut · **Posted:** Tue May 19, 2009 6:44 pm

Xodius wrote:

I just made a run to the local Lowes and it ran good. I did pop the hood and double check everything one more time. I did notice something that I did not before. The cap that goes on the low pressure port, there is a washer or something like that inside, it was all chewed up and actually went flying when I took off the cap. I am wondering if that could have been the issue...if the seal was off just enough to hit the valve stem.
Anyone know if that piece is really needed? Would that be the issue?

I think all the washer does is keep moisture and dirt from getting into the springloaded valve. Ie, it's not the source of your leak if you have one. However, it's possible that some moisture or dirt got to that valve and it's corroded and your leak is there. Get someone with one of those detection tools to scan for leaks.

AC or belt?

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