Overheating & Stumped Why?

[Broncolover]

2000 Ford Explorer Limited 4.0 SOHC
I have a crazy problem.. Here goes... In traffic w/ AC running the truck will quickly overheat... without the ac on it steadily climbs and gets to hot. The truck temp gauge just teeters on the line of being hot, but not actually boiling over. It gets to the point where the ac stops blowing cold. O.k. in the past week I tried several things to no avail.
First I replaced fan clutch.. didnt work... took the clutch back and got another... still didnt help....

Well Then I bought a waterpump and just went at it and replaced the water pump.... didnt help. Before doing the Pump, I went ahead and flushed the system out with my garden hose hooked up to my prestone flush system I have installed in the heater hose. I flush/Fill every year.

Today I replaced the thermostat with Napa brand 192 degree Stat and took it for a test drive and it still is overheating. Some could say air in the system? after the thermo and after the water pump fiasco? I dunno? I ran the heat on full blast for the 15 minute ride back from the thermostat test run. It has been really hot here in Atlanta... the other day the temp gauge for outside air was showing 104 degrees.... The truck was running hot and I had the freaking heat running to cool it down... that sucked in Atlanta traffic!\

Any Ideas? I am by no means a master mechanic... I'm still learning.

 

[offset_98]

Happend on my Expedition and it turned out I needed a new radiator. Problem solved. But...it got to that point after I too changed all the cheaper parts out first too! lol

 

[anthonytony]

radiator

 

[budwich]

There is a similar thread over in the "under the hood".... very frustrate poster (and helpers). Similar process has been followed... cheaper parts first.... last thing appears to be the rad. Although I suggested one more possibility of the lower rad hose collapsing under the suction of the pump.... assuming that the hose is very old and the rubber is soft. As suggested in the other thread, run without a thermostat and see if your condition changes. That might help you with more clues.

 

[Mbrooks420]

Has the gauge ever been all the way up, or has the motor ever actually been overheated?

 

[marragtop]

Try a new radiator cap. It's worth a shot. Also, as the previous poster stated, check to see if the hoses are collapsed when it's having the problem.

 

[Ray Lobato]

Well I can tell you that a collapsed hose WILL cause this problem.

 

[old mechanic]

Yup! I have seen many a vehicle with mostly the lower radiator hose collapsing while driving and it caused overheating.
I can personally testify to that several times in my repair work and I once bought a nice car for cheap money but the guy never told ne he had replaced almost everything and it was still overheating. I drove it a few miles and it was steaming. After seeing everything new under the hood, I checked the radiator hoses and sure enough you could squeeze the lower hose with your two baby fingers. Very spongy. Changed it and sold it for twice the money.
He finnaly asked me if it overheated on me and I said, oh ya, but a $5.00 radiator hose fixed it. He was bullshit.

 

[BrooklynBay]

There was a thread about the water wetter additive which claimed to reduce the temperature by about 30 degrees. You cound put it to the test, and see if it really works.

 

[Ray Lobato]

There was a thread about the water wetter additive which claimed to reduce the temperature by about 30 degrees. You cound put it to the test, and see if it really works.

This would only be masking the problem and not fixing it. Please don't do that.
Let's fix it correctly. Check the hoses first, especially the lower hose.

 

[jreece04]

just some advice, don't be quick to blame the radiator, I am having a very similar problem. I have replaced Tstat, radiator cap, hoses (upper and lower) and then decided that the radiator was clogged so I replaced it, (Radiatorbarn.com $111 shipped) I am still having the overheating problem, I have a heavy duty clutch and a new fan on the way but I have a nagging feeling that it is the water pump. hope that helps

 

[Mbrooks420]

If it's ever been overheated to any degree you may have cracked or warped the heads. These heads are known for cracking easily. You may have already fixed the problem, but have a new one.

 

[Rustang©]

THE person above me is right about the cracked head ordeal, i had a very similar prblem with my 4.0, although not a SOHC its still a ford, check your oil and see if its oil or if its a white wattery mix, if so you either cracked the block or lost a head gastket, or both.

Good Luck man