Clattering: A/C Compressor? Bypass? Repair? -
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Unread 04-08-2008, 06:37 PM   #1
Registered User
1988 MJ Comanche 
Join Date: Apr 2008
Location: New York
Posts: 3
Clattering: A/C Compressor? Bypass? Repair?

Hi all: I'm new to this forum and my Jeep, but not new to repairs of this vintage and older (1988)

I just got a 1988 Comanche 6 cyl. 130,000 miles. Body rust issues, but not too bad. Engine and power train look well maintained, lots of power. Seems to run fine. Burns a little oil (maybe 1/3 quart on 65 mile trip).

On its maiden voyage, a clattering appeared. It seems to be coming from the A/C Compressor pully or idler pulley. Engine performance hasn't changed.

I tried disconnecting the wire lead to the clutch, but that didn't do it. No surprise, the compressor shouldn't have been engaged anyway. The A/C hasn't worked in some time, according to previous owner, so the compressor may have run out of lubrication?

The last car I had was a '96 Dodge Stratus, and its A/C compressor seized and shredded the belt. I repaired it by trying a few different shorter serpentine belts to find one that would work with the A/C compressor out of the loop. That worked perfectly.

Is this a similar situation, or does the clattering even when the clutch is disconnected a more ominous sign?


PS. Any recommendations about where to get FSM or other useful manuals welcome!

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Unread 04-09-2008, 02:02 PM   #2
Registered User
1988 MJ Comanche 
Join Date: Apr 2008
Location: New York
Posts: 3
Here was the solution:

The idler wheel that keeps tension on the belt (located right next to the compressor) had lost all its' ball bearings! All that was required was to replace the idler. I needed to get the Jeep inspected, so I had the shop that had serviced the vehicle for the previous owner do it. They had no problem getting the part, and even with their markup and labor cost, the total expense was about $45. However, if I hadn't already pretty much diagnosed the problem, and if I didn't have my experience at dealing with repair shops, that price could no doubt have soared with the unnecessary replacement of working parts.

I learned something unrelated in the transaction. The 6cyl engine fuel injection doesn't engage immediately in most Jeeps. There's no need to give it gas to start it, you just need to let it crank till the fuel injectors kick in. It seems to take forever compared to most cars I've had. In retrospect, it didn't seem giving it gas really started the engine faster anyway, but I was concerned about a soft battery succumbing to the extra cranking.
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