91 expl overheating

[jstagn]

Cooling system pressure tested, no leaks, new radiator, fan, hoses,theromstat,Rad cap (13psi).No 'wobble' in original water pump pulley (OK?). Cools fine except runs hotter with AC on and overheats in traffic with AC on. AC compressor seems to be making some noise but cools fine, could it be creating enough drag to overheat engine?? How should I check. Engine runs great, but last tuneup was about 15K ago.

 

[Skip Pendle]

Check your exhaust system for blockage or restrictions. A significant portion of engine cooling is via the exhaust gases, not just the radiator, and any restriction of exhaust flow will make the engine run hotter. With the engine between 1500 and 2000 RPM, listen at the exhaust pipe (taking care to not get burned by the exhaust gas) for the sound of something like a compressed air leak which is an indication of a blocked CAT or muffler or a crushed pipe.

Good Luck.

[This message has been edited by Skip Pendle (edited 05-15-2000).]

 

[A91EBexplorer4x4]

jstagn, Boy do i know the anger you have , i had this same problem with my 91. it turned out i needed a new radiator but i see thats not your case. although the fan is turning it has the clutch type and you might see it turning fast but it might not be turning as fast as it needs to be. just a thought and a new clutch would fix that problem. good luck man. Later

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1991 Eddie Bauer 4x4
K&N drop in filter, Modified air box.
3" lift 31x10.50's
Dunlop R/V's.
Sway bar quick disconects disc.http://www.freeyellow.com/members8/91fordexplorer/index.html