High deltas....need advice on how to proceed
I will try and keep this brief, but explain in enough detail. Looking for advice on how to go forward with this truck.
Truck is an 05 F250 4x2 CC that my dad has owned since 88k miles. Truck has roughly 130k on it now. There was NO MONITOR in this truck until recently, so unfortunatly we don't know what the temps were previously.
At about 125k miles, dad noticed the truck was losing coolant. We finally diagnosed it as the dreaded orange hose under the turbo. Since we were going that far, the shop did all of the following at one time.
1st...non chemical flush (this may be the problem)
Replaced orange hose of course
MPRP full exhaust
New oil cooler
Sinister coolant filter
Picked truck up, ran great, coolant leak fixed and temps were great. 5-8 degree deltas and all was good.
I explained to dad to watch the ECT/EOT difference closely as that was one of the main reasons he bought the thing LOL. I've owned 6.0L trucks, but this is dads first one. After about 1500 miles he noticed the delta's starting to climb slowly. Then within about 100 miles deltas went from 10ish degrees, to 20-25 degrees (can an oil cooler clog this fast?). This is at 60mph on flat roads in south GA. On the interstate at 75mph (unloaded) can be as high as 30 degrees. ECT 190-192. EOT 210-220.
I cut open the first coolant filter after roughly 1000 miles and didn't see anything bad. The little bit of stuff that was in it looked like rust. Very small pieces and not much at all. Better than I expected. Didn't see any of the gooey stuff I've seen pictures of on here. Took the truck back to the shop (good friend) that did the install. He did a backflush on the oil cooler, and me and him both knew it was doubtful it would help. And it didnt. Temps really didn't change at all.
So....at this point what do we do? After doing a lot of reading on here, I'm thinking to do the complete Restore/Restore+ coolant flush and replace the oil cooler again.....HOPEFULLY for the last time. Dad has put roughly 5000 miles on the truck with the coolant filter, so I'm thinking between what is caught in the oil cooler, and the system being filtered for 5000 miles, it should be pretty clean now.
Does anyone have any other thoughts or plan of action in our situation. What I'm really after is the exact order I should do this. It is doubtful we can do the flush and oil cooler at the same time/weekend.
Complete flush one weekend.....then change oil cooler the following? Should I leave the current coolant filter installed thru the entire process until totally done then change?
Thanks in advance for any advice.