Hi all,
This summer, I've noticed a few things different. My A/C hasn't been as cold, my gas milage has dropped quite a bit, I've lost some power. More concerning, I have noticed a few times a 'winding down' sound, like a bearing, when I turn off the Jeep. At first, I thought it might be the Turbo, but i replaced it 6 months ago. It makes more sense, with everything else, that the AC compressor may be going out.

Does this sound right? Would I just need a new clutch, or do I need to replace the whole unit? Is there a walk through somewhere on how to replace the clutch?

Thanks!
. . . Shawn

I have seen on this site several people replacing only the aircon clutch....the clutch air gap is critical apparently and has to be shimmed correctly.
Your loss of power and bad consumption is probably a different matter altogether though.
You should take your jeep to an airconditioning shop to have the gas checked for leaks and then get a top up if needed.
Does the "winding down" sound only happen with the aircon ON?
Your clutch on the alternator pulley may be packing up and causing that noise.

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2002 Export CRD 2.5 Sport

I'm not an AC person but there are some basic checks on the AC that are worth doing before bringing in a professional.

Basic AC performance is easy to check, see the FSM, by using a thermometer to check the temperature of your AC output. My notes for an 05 say AC performace can be checked with thermometer as long as there is no significant drop in perfomance at "idle" (e.g. ca. 1,000 rpm). See service manual pages 24-4 & 5 for test method. Do test after car FULLY cooled which takes about 10 miles on a really hot day at max. AC. June 2010 readings for my CRD were 45 and 48 at 75 and 95F ambient respectively. Alternatively your system can be fully evacuated and the coolant recovered is weighed to see if you have enough; apparently checking newer car AC systems with just a gauge gives pressure readings, which may be enough, but does not indicate if "enough" coolant is in the system.

AC performance is also influenced by cooling across the condensor coil at the front of the vehicle which can be adversely impacted by clogged fins (in that condensor or in the radiator between it and the engine) or power performance of the electric fan just behind the grill or the main engine fan. As our KJs do not have a cabin air filter I suspect it's also possible to get trash thru the grill in front of the windshield and down into the heater/AC core and have a clogged "radiator" inside there. I know this was a serious problem on my 1993 Dodge Cummins until I cut a hole in the heater/AC core box (eventually closed it with a small screw in boat access port), shoveled out all the junk, and put some window screen on the underside of the referenced grill). Unfortunately I don't know how to get into the KJs heater/AC core.

I suspect your mpg drop may not be related but am not sure. The "winding down" sound could be a stuck FCV (flow control valve). The sound is the FCV motor trying to close the valve which doesn't work due to the plastic gears being stripped. The valve generally fails open, which is harmless, but if it fails closed, which does happen, or partially closed it can impact mpg. Have you inspected, off the vehicle, your turbo>intercooler>engine hoses, assuming they are OEM and the air filter box to turbo hose?

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

I'll double check the turbo lines. The winding down sound is not consistent. I heard it last night when I got home and a few days ago when I got home (about a 45 minutes drive with the AC on). I thought it might be the clutch or the bearing in the AC condenser since it seemed to come and go. When my turbo went out, the noise was constant and could be heard while driving. This was quite different.

I have noticed that my Jeep has started to overheat while driving around town with the AC on. It hasn't done this before, but it HAS been 95+ degrees the last week or so (the coolant has been flushed and filled recently). To me, it just seems that there is an additional drag on the engine that shouldn't be there. I was thinking that the compressor was working too hard and slowing things down, but it could be something else.

Where and what is the FCV?

The, presumably/hopefully minor, overheating and not so good AC performance could very well be related. All the folks who have upgraded their main engine fan (Hayden fan clutch or kap's fixed fan) report improved AC performance. That brings to mind that you likely should also check you main engine fan clutch for failure, there is a method mentioned in the FSM and in the forum that involves partially blocking the grill and with a termometer in the air flow raising the engine temp to when the fan should kick in. If you have a bad OEM fan clutch, very common, it could cause both poor AC performance and a hot engine. Search the forum for "hayden" for some discussion. For what it's worth my temp gauge and, I believe, stoutdog's both stay straight up with the AC on at ambient temps of 95 and well over 100 respectively.

The winding down sound does not sound like AC compressor. That is belt driven off the engine such that, as far as I know, when the engine stops the compressor immediately stops hence no wind down sound. I think??? the turbo would be the same (e.g. no run on spinning after engine stops) but maybe not. If you have someone who can stand in the engine compartment vicinity with the hood up while doing a shutdown perhaps you could narrow down where the noise is coming from.

The FCV, Flow Control Valve, EGR air valve, or EGR air control valve are all the same thing. For a picture see viewtopic.php?f=5&t=60485&hilit=flow+control+valve. For location see page 25-35 of SirSam's NOOB guide version of the 2006 FSM. Apparently if the plastic gears are going it can cause a runon noise after the engine is keyed off as systems shut down. Lots of chat on the forum about failure mode, associated codes, impact on performance and mpg, etc. It's pricey and really doesn't "do" much useful so a common fix is leave it failed open mode or put it into failed open mode if it fails closed and either ignore the MIL/CEL or get a GDE tune which makes the MIL/CEL go away.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

I was able to capture the sound on my phone. After listening to it a few times, it sounds more like an exhaust leak. I'll upload to youtube when I get a chance and post a link here. It's different from outside the cab (:

So, if that's the case, there's probably a few things going on
1. exhaust leak (I'm not TOO worried about it, I know where it most likely at), could be the FCV
2. over heating (only happens when the AC is on. It's been in the upper 90's for like 10 straight day here, ugh)
3. AC not up to par (related to over heating??)

I'll run though the tests that you guys have outline above and get back to you all.

Thanks!

If the sound you captured was immediately after the engine stopped I would not think it's an exhaust leak. It could, however be a vacuum leak.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs