2001 5.4l Overheating

[JohnnyZ]

Hello everyone. I am a new member having some issues with my Expedition. I Bought a high mileage 2001 expedition about a year ago, the price was right. Had to do a few things to it such as replace battery, alternator, and brakes all the way around. It ran fine over the course of the year then suddenly developed a coolant leak from the water jacket on the intake manifold. I removed the manifold and found the aluminum broke at the seal on the passenger side. I bought a new Dorman intake manifold and replaced it. Everything went back together good. Took it out for a test drive and everything seemed fine. Drove it to work (40 miles round trip) and all was good on the drive in. On the way back, however, about half-way home (about 10 miles) the temperature guage jumped right up to the red. It was a hot day so had the air conditioner running, not sure if that had anything to do with it. I pulled over, let it cool off and was able to get it home (with one more stop due to overheating). When I got home I took the radiator out and flushed it out, did a flow test and coolant is flowing freely through the radiator. Put it all back together and took it out for a other test drive. All was good for about 30 minutes and then the temp gauge started inching upwards. I was running the air conditioner for about half the time I was driving (again not sure if that had any bearing on the issue at all). It has a new thermostat that came with the Dorman intake manifold, so that shouldn't be the issue. The only other thing I can think of is water pump, but why would it run normal for 30 minutes (drove about 30 miles or so) before it began overheating. Anyone have any ideas?

 

[stamp11127]

Did you bleed the cooling system?
Radiator will still flow if all but one row is clogged - ends up overheating after a while. Better to take temperature readings or just replace it and the water pump as maintenance items.
Is the fan clutch working correctly?

 

[JohnnyZ]

I did not bleed the cooling system. The fan clutch is working correctly. How do I go about bleeding the cooling system?

 

[stamp11127]

Park so that the overflow tank/surge tank is the highest part of the cooling system. A steep incline will work just fine.
Run engine up to temp enough to open the t-stat. Squeeze the upper rad hose repeatedly to help dislodge any trapped air bubbles. Once you are not getting any more bubbles you can stop. You will hear and feel the difference in the hose.
Let cool and refill coolant as necessary.

If you are mixing the coolant make sure you use distilled water and not tap water.

 

[JohnnyZ]

Thanks! I'll do that. Thanks for the info.

 

[AbbadonTD]

Blow out your heater core too, it could be running clogged up and causing it to not move fast enough.

Turning your heater on high when overheating can help sometimes by opening up the fluid space.

 

[JohnnyZ]

Thanks for all the input. It turned out the new thermostat that came with the new intake manifold was bad. Bought a new one for $12 at NAPA and it hasn't overheated since.