Engine overheating

[eddiewolfgang]

2003 Ford Explorer 4.0. Started overheating while driving. Pulled over & ck for leaks & coolant level. Coolant level was at the max mark & no leaks in cooling system as far as outside the eng.
I just replaced the thermostat housing & thermostat not too long ago due to a leak.
I let the engine cool down a little & started it back up, eng temp went back to normal & coolant level dropped to min mark.
The engine fan runs at idle. I noticed some coolant flowing from the return line into the reservoir but it looks like its just spitting, not an actual flow, not sure if this is normal.
Also when eng starts overheating, by turning on the heat, eng starts to cool down right away.
I think its either a blockage somewhere or water pump is intermittently inop.
What do you think?

 

[Joe in NY]

clean out the radiator. My friends f150 was over heating, never bothered to clean the rad after mudding multiple times... Cleaned with a hose, no more overheating... Also check your pressure cap. Fords pressure caps suck, the stock ones fail often and don't hold pressure so your coolant boils and you overheat...

 

[eddiewolfgang]

Ok im gonna try that. Flush radiator & replace pressure cap & see what happens. Thnx

 

[cross6]

I just replaced the thermostat housing & thermostat

Probably got a junk thermostat. Happens more and more these days. Does the upper hose ever get hot?

 

[Joe in NY]

I dont mean drain and flush the internals of the rad (although they can plug up!), I literally mean clean out the radiator's external air passages.

for my friends f150 with only the 4.6L! : The rad its self had a thick carpet of mud and grass built up on it(somehow skipped over the ac condenser...). The fan was fully engaged but couldn't move a breath of air to save its life... Until I cleaned it out and fixed it for free. My friend had already replaced the t-stat and bought a new water pump, I was supposed to help install it... He got his $50 back

 

[Number4]

When you turn on the heat, did you have the blower going as well? If so, then it was acting like the fan/clutch assembly.
Perhaps your fan clutch itself is bad and not cooling the radiator properly.

 

[cross6]

When you turn on the heat, did you have the blower going as well? If so, then it was acting like the fan/clutch assembly.
Perhaps your fan clutch itself is bad and not cooling the radiator properly.

You'll still have heat with a stuck thermostat.

 

[eddiewolfgang]

This morning woke up to go to work, with eng all cooled down. Decided to check coolant level, found it low, just beneath min mark. No leaks, all dry.
Topped it up, drove to work & back, everything is back to normal.
No more overheating.
Yes the top hose does get hot when eng warms up.

 

[cross6]

This morning woke up to go to work, with eng all cooled down. Decided to check coolant level, found it low, just beneath min mark. No leaks, all dry.
Topped it up, drove to work & back, everything is back to normal.
No more overheating.
Yes the top hose does get hot when eng warms up.

You might have had an airlock that finally burped. But still keep an eye on the coolant level and make sure it doesn't keep dropping. Your new housing could be leaking into the valley.

 

[Sedition]

Does your fan actually kick in and start roaring? or just operating silently.

 

[eddiewolfgang]

Does your fan actually kick in and start roaring? or just operating silently.

The fan clutch is brand new. Yes it starts roaring when starting up eng.

Car still overheating

 

[PDXDawg]

My wife's Ex was doing the same (100K miles)...heat especially spiked when car sat idle - had to turn off the engine sitting in DQ drive through. We did find the fabled cracked T-stat housing as well - but the issue was a failing water pump . Replaced the water pump & T-stat housing and now the gauge never gets above 1/2 on the heat. Good timing since it hit 104 the other day and she never batted an eye..

 

[eddiewolfgang]

Problem fixed

Ok guys i fixed the problem.
It was the radiator, the inside was restricted & outside was very dirty. So i just replaced the radiator & tada problem fixed.

I also found a small leak on my condenser upon removing the radiator.

I appreciate everyone's help on this, thank you all.