Overheating at Idle (76' 440-3)

[BrianW21]

Well I survived my week at BurningMan with only replacing a worn out electric fuel pump (5 minutes). But while waiting in line to enter the engine would get very hot.

Just moving 10-15 miles an hour would fix the issue, but at a standstill in park or in gear the engine starts to get hot. Put it in neutral and rev it to 2000 rpm and temps come right back down.

Running around and up hills, she never even get warm.

So I attribute this to lack of airflow and low output from the mechanical fan at idle. If this is the case then I though a cheap $80 electric fan wired to a switch on the dash would be the easiest option for the once a year I have to sit in line for 2-3 hours.

What do you think?

[GulfCoastFighter0]

Sounds good to me, however, have you checked your water flow at idle?  I had an old truck that just wouldn't flow enough water at idle to cool the engine.  A new water pump was needed to fix the problem.

[denisondc]

If you have a mechanically driven fan, it probably has a fan clutch on it - or did when the chassis was made.  I would replace the fan clutch first.  They age slowly and never just die, like an alternator for instance.  They simply lose there ability to spin then fan when they should - which is at low rpm mostly.  Once you are moving along the highway, you wont need a fan, but at very slow speed - the fan clutch needs to be healthy.
   And of course, the 440-3 takes a particular style of thermostat.  If you look inside the opening where the thermostat sits, (with the hose outlet casting removed), I think you will see a lower ring in the water pump housing casting.  This requires the thermostat pictured here:  http://static.summitracing.com/global/images/prod/large/mrg-4367_w.jpg
My water temp would wander up and down without reason - until I installed this type of thermostat.  You can also get it from:
www.stewartcomponents.com.   Their image of the parts shows it from the side:
http://www.stewartcomponents.net/Merchant2/graphics/00000001/thermostat.gif
Personally I prefer the mrg 4366, which is a 160 degree thermostat.  Our Winny doesnt get operated in cold weather, and running too cool is NOT a problem in the south tip of Texas.
  The original water pumps on the Dodge chassis were also a high-flow type, and the radiators were larger/thicker than what came on the vans and pickups - even if they had a 440-1 under the hood.