Overheat still

[CTfirefighter]

Hi. Newly registered to the forum but long time reader. 97 Ranger 3.0. Was overheating often around town driving. Newly installed radiator, hoses, upgraded heavy duty fan clutch, flushed system multiple times. Not overheating on highway or as long as it’s driving/accelerating-Only overheats on idle (traffic) after engine is warm. No evidence of head gasket issues and no coolant leaks. Any ideas? And can an electric fan be added to assist airflow during idle? Thanks in advance.

 

[Sharky]

that kind of over heating condition is from not enough air flow, need a better, more efficient fan
(or larger) with a fan shroud.

 

[2011Supercab]

Is the fan shroud in place?

Another possibility is the water pump impeller blades have deteriorated and not moving enough coolant.

 

[RobbieD]

Welcome (as a member and not a lurker ).

The parts cannon "should" have fixed it. The symptom sounds like a bad fan clutch, as in lack of air flow when the truck is not moving fast. But "new" parts these days seems to be luck of the draw. You should be able to hear a heavy duty fan clutch when a cool motor is first started. And the fan should move easy by hand when cold and noticeably stiffer after a warmed up engine is turned off.

If the new fan clutch checks out good, here's two other out-of-left-field thoughts.

First, when the radiator was replaced, were any foam gasket or rubber sealing pieces left off? Especially if the truck has AC, there are usually foam strips sealing the sides and rubber flaps clipped in to better enclose the top and bottom, between the AC condenser and the radiator, and to the radiator support. These help keep the air flow directed through the radiator instead of escaping around it. And is the AC condenser clean too? And the fan shroud was replaced? No missing fan blades?

Second, is the transmission fluid at the correct level, and does the truck have a separate trans cooler? If the trans is running hotter than usual (low fluid), I can see this tipping the cooling system into overheating in hot day / slow traffic conditions.

You didn't mention a new thermostat; a good one is still relatively cheap, and worth a shot. The water pump is another consideration; you should be able to see a good flow looking through radiator cap inlet before the system pressurizes.

There's nothing wrong with adding a helper fan, but if it were me, I'd rather figure why the original design cooling system is not doing its job, before modifying the system around an unrecognized problem.

Good luck!

 

[CTfirefighter]

that kind of over heating condition is from not enough air flow, need a better, more efficient fan
(or larger) with a fan shroud.

Thanks. The fan and shroud are there and original to the truck. Seem to be in good shape. Truck only has 90 K miles on it.

 

[CTfirefighter]

Welcome (as a member and not a lurker ).

The parts cannon "should" have fixed it. The symptom sounds like a bad fan clutch, as in lack of air flow when the truck is not moving fast. But "new" parts these days seems to be luck of the draw. You should be able to hear a heavy duty fan clutch when a cool motor is first started. And the fan should move easy by hand when cold and noticeably stiffer after a warmed up engine is turned off.

If the new fan clutch checks out good, here's two other out-of-left-field thoughts.

First, when the radiator was replaced, were any foam gasket or rubber sealing pieces left off? Especially if the truck has AC, there are usually foam strips sealing the sides and rubber flaps clipped in to better enclose the top and bottom, between the AC condenser and the radiator, and to the radiator support. These help keep the air flow directed through the radiator instead of escaping around it. And is the AC condenser clean too? And the fan shroud was replaced? No missing fan blades?

Second, is the transmission fluid at the correct level, and does the truck have a separate trans cooler? If the trans is running hotter than usual (low fluid), I can see this tipping the cooling system into overheating in hot day / slow traffic conditions.

You didn't mention a new thermostat; a good one is still relatively cheap, and worth a shot. The water pump is another consideration; you should be able to see a good flow looking through radiator cap inlet before the system pressurizes.

There's nothing wrong with adding a helper fan, but if it were me, I'd rather figure why the original design cooling system is not doing its job, before modifying the system around an unrecognized problem.

Good luck!

New Fan clutch is oversized and working correctly. Probably try a water pump and thermostat. Flushed heater core and heat/defroster and ac works well. tRNAs fluid is normal.

 

[bobbywalter]

sounds pump related....is the belt on right? pump is running right direction?

seems headgasket would be pushing water.


that thing dont even need a shroud if the fan is sort of working.

is it actually getting hot? you verified it with temp gun? might be bad wiring/sender