I’ll try and make this as short as possible. I have an 02 7.3 excursion. Bigger turbo, stage 1.5 ffd single shot injectors, stage 2 cancer fab hpop, had crossover, 4” intake and exhaust, billet injector cups, riff raff dog house and boost fooler, and epbv delete. In December I started having high transmission temps bunch of metal in the trans cooler lines and radiator. Flushed it all but trans was done. I got a Warren diesel comp trans (temps run about 140 on a 75 degree day). Just before I took it to get the trans I flushed the coolant system and replaced the oil cooler and radiator (xdp oil cooler and xdp xtra cool radiator). I used a new motorcraft 195* thermostat and delo elc (cat - ec1) 50/50. I also added an edge cts3 to monitor as much as I can. Added egt, fuel pressure, and boost pressure.

I’ve been watching the EOT temps. On the highway doing 75 on a 70* ish day my EOT temps are about 221. That just cruising, not being aggressive or towing. As soon as I slow down or park the temps come down to about 199 - 203. Thought I had a bad sensor so I swapped it for a new motorcraft one. I shot the thermostat housing with an or temp gun it was about 177. I also shot the hpop reservoir, it was 184 while the sensor said 203. Figured it was the difference between inside and outside the motor. The upper radiator hose was a little cooler then the about 171 while the lower was about 123. From what I’ve read that way too big of a delta t. Pulled the thermostat and boiled it. It started opening right about 190 and fully open at 195. Thought it might be the water pump but I can’t figure out how to check the flow. I did crack the heater hose to the block and coolant was coming out while the truck was running but I can’t remember if the degas tank cap was off or not. After I buttoned up the system and bled it I drove it for a bit to get up to temp. The water pump is about 4 years old and not leaking that I can see. Felt okay when I spun it. When I rev the engine while bleeding I can see the coolant drop in the tank slightly. When the truck is hot (after a highway run with the Eot at 210 or higher) I checked the degas tank because I thought coolant was supposed to flow through the little hose on the right side when the thermostat was open. It’s not. Also the fan turns when the truck is off and cool but it doesn’t spin freely so I’m not sure if that’s okay or not. When I rev up the motor to about 2000 rpm’s the fan is still going and doesn’t seem to slow down at all. I used a piece of cardboard to see if it was spinning freely and it didn’t seem it was. Tore the cardboard up.

my questions

1. how do I know if the coolant isn’t circulating?

2. could the fan clutch be bad and will that cause high highway temps?

3. Could the new oil cooler be causing my coolant flow and high Eot temps?
i shot the oil cooler with the temp gun. Oil filter was 208 outside of the long section was in the 130s the end towards the front was 193.

4. could the new oil cooler be causing the coolant restriction?

any help would be appreciated. I’m racking my brain but can’t find much on this

 

This is a 7.3L gas engine thread. May want to find the 7.3L diesel thread.🤷‍♂️

 

Oh shoot. Thanks for the heads up