Re: Overheating
 

I know on the 6, there are two water pumps, I think the 4 could be the
same.

One is a normal pump for a V belt, the other is a reverse rotation one
for a serpentine belt.

The pump impellers also can break off.

A blown head gasket can cause that. To test heat it up with the rad cap
off and watch for smoke. Then when the t-stat opens watch for an
explosion of pressure, once it settles down, you can put your hand over
the opening and feel for puffs in time with that slight miss you hear...

Mega bubbles is bad news. When my head gasket blew and I had an
overheating problem, it looked like I had dish soap in my rad. Tiny
bubbles.....

Then a scaled up rad also can be a problem, that happens after a good
off road trip on a vehicle that wasn't used to vibration lots. All the
scale knocks loose and drops to the bottom of the vanes plugging them up
at the ends.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Craig wrote:
>
> Hi,
>
> What do I check for overheating 2.5L, 86 Comanche with AC, powersteering?
> I've changed fluids, thermostat, added electric fan, new radiator cap, and
> water pump?
>
> Water boils into my overflow bottle and red idiot light comes on. Engine
> trys to die when I push in the clutch. Engine starts fine and seems to have
> normal power for a 2.5. But I can't run for more than 30 minutes or so with
> AC on before it overheats.
>
> Truck has 129k miles and is in great condition otherwise.
>
> Thanks,
>
> Craig W.
> 86 Comanche
> 02 Wrangler Sport