I have been scouring forums and Google looking for the issue I am having with my truck and I am hoping someone can provide some insight.
Sorry for the long post but I am going to try to answer the question I would ask.
I have maintenance my truck at half intervals of what ford calls for, oil and filter every 5k, and fuel filter every 10k. I did my transmission and coolant the first time at 30k, and replaced the coolant with the gold stuff at them time.
The Truck developed a radiator leak last fall. I believe I caught this early enough as the truck is parked on concrete when I noticed it; I stopped driving it and ordered parts. I replaced the radiator, and while I was at it, did a full erg delete, replaced the coolant with fleet service ELC, new thermostats, upgraded the thermostat hose to the white one and all was well.
This summer I started noticing that my Oil Temp was creeping up a bit, nothing too bad, 203 as a high on the interstate (Yes I am a gauge junky). So I went back to watching my spread, ECT to EOT, and they maintained no more than a 5* spread.
Over the summer this has progressively gotten worse with the same outside temps as before (80ís Ė 90ís). I still see the same spread but the temps kept ticking up, to where now running on level ground at 70mph I frequently see 206 EOT, with an ECT of 200 to 202, not towing. Not bad from what I have read, but what I am noticing is that ECT temps spike and drop with acceleration. I pull a ramp to get on the interstate and I will go from 194* ECT to say 200, and my oil temp will soon follow and climb to the 206 range and maintain. Getting off the interstate for example sitting at light waiting to turn all temps come back in line, 194 ECT and 199 EOT. As soon as I start to move again so do the temps. My concern is how fast the ECT temps are moving, I mean in a couple hundred feet, under normal acceleration it will go from *194 -196* to 200 or over? It shouldnít move this fast. On some cooler nights, my temps donít get as high, but I am still seeing the same ECT movement. So I parked it.
I donít get it? The truck runs great, I donít see evidence of oil in the coolant; I donít see evidence of puking, curious if it maybe a clogged oil cooler, head gaskets, water pump?
I am planning on changing the thermostats this weekend with fingers crossed it fixes this issue, figured itís the cheapest simplest place to start.
Thoughts, advise, punches to the gut (oil cooler)?