Thoughts & Opinions

[rwjejits]

2004 F250 with 6.0; 134k miles, Bought new by me in late 2003
Pretty much stock with the exception of 4" exhaust and EGR cooler welded up.

Truck is running fine. Typical fluid changes / flushes (most recent coolant flush was ~6k miles ago). Only issue to date has been needing to replace FICM (~5k miles ago). Coolant level steady at low fill line.

So I broke down and bought me a SGII several weeks ago (Amazon $122) and here is the scoop. After warming up and doing the 65mph test, readings are ECT @ 178 / EOT @ 201.

So two obvious issues here. Thermostat is bad and deltas are out of range (oil cooler restricted). I am prepared to replace the oil cooler soon, but the question is should I replace the thermostat now or wait till cooler is swapped out? I'm afraid if I swap out the t-stat now and if deltas track each other, EOT will run even higher and lead to failure before I'm able to schedule the repairs.

If deltas do not track each other, then just swapping the t-stat may show that things aren't as bad as I had originally thought.

So if you were in my shoes, what would you do? Also, what is a fair price for parts & labor to change the oil cooler? Will likely have this done at Powerstroke Magic in Houston.

[duc796]

I would try replacing the t-stat first and if the deltas are still way out then go for the oil cooler. When I did my flush I replaced my t-stat anyways that way I could pull the guts out of it and the coolant will flow reguardless of the temp. Looking at your temps that is what it looks like to me so that is what I would do if I were you. Start with the cheap part first.