radiator or water pump

[jpcjguy]

Hi all,

Have a 2002 Excursion 7.3L with about 89K on it. Live in Richmond, VA. I do have a DP Tuner and have it on 80 economy setting.

Now a little history on the truck - little that I know - Sarasota, FL truck - previous owner had some heating issues. Vehicle was owned by the wife of a trailer company owner. Sometimes it was used to move empty trailers (from car trailers to larger enclosed trailers) and it the temp would rise. She had the cooling system flushed(not sure what procedure was used or who did it) (at least what she told me over the phone). She said it never got into the red - always pulled over and let it cool back down. When I drove it back from Orlando last October it did this one time when I was in FL. Turned off the AC and slowed down and it eventually settled down after about 5-8 minutes. That was interstate driving - never pulled over. Obviously never had an issue over the winter.
Been chasing this overheating issue now. Installed a regular gauge ($17 - autozone) to let me know what the actual temp is. Did this in the extra port on the water pump.

Now it has been hot as heck here in Richmond, VA and driving around without AC and she is running 205-210. When it was 102 degrees out, I was driving aggressively and had the AC cranked I watched the temp gauge get to 235 before I killed the AC and cranked the heat and idled on the side of the road. She came back down to the 210-215 mark.
I did another test a few days go - low 90s outside. Got in and cranked the AC and let it idle - never got about 195 after 15 minutes. Drove about 6 miles and it got up to 215. Idled in a parking lot with AC on for 5 minutes and it stayed there. Turned AC off and after about 8-10 minutes it dropped down to about 198. So it is obviously under load where i have an issue....What the heck?!?

I put a new from NAPA fan clutch on and still can't here that "roar" that is supposed to happen when it kicks in that everyone talks about. I also did a complete cooling system flush according to Gooch's procedure and used fleetrite ELC. This was done about 2 weeks ago.

Right now I am trying to figure out if it is my radiator or water pump - really don't want to start dropping more $$$ until I pinpoint it. The thermostat is fine - watch the temp get to 205 and then drop back to 195 as it opens.

Also - I am wondering what is acceptable temps for this motor? Where is the danger zone?

Thanks
Joe

[dhanna6powerstroke]

203* is the optimum temp. for the motor. I have seen the impellers on the water pump deteriorate because of not putting the additive in the cooling system and throwing the PH levels off. If the radiator isn't leaking and water flows through it ok, I would lean towards the water pump.

[jpcjguy]

Originally Posted by dhanna6powerstroke

203* is the optimum temp. for the motor. I have seen the impellers on the water pump deteriorate because of not putting the additive in the cooling system and throwing the PH levels off. If the radiator isn't leaking and water flows through it ok, I would lean towards the water pump.

The green coolant that I flushed out was not the greatest looking....wish I kept some to test..

[dhanna6powerstroke]

Originally Posted by jpcjguy

The green coolant that I flushed out was not the greatest looking....wish I kept some to test..

Did you put additive in the new coolant or is it already mixed in?

[jpcjguy]

Originally Posted by dhanna6powerstroke

Did you put additive in the new coolant or is it already mixed in?

The new coolant, ELC, does not need additives.

[jc82chevyman]

i would also lean towards the water pump the easiest way to check your radiator is with a digital thermometer start at the top and work your way down it should gradually be cooling if there is a huge drop in temps then you rad is probably plugged

[jpcjguy]

How do you do that with the fan, shroud, etc. all in the way?