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Steve here. F250 6.0 2006. Got a new scanner and did EOT, ECT test. 20 miles at 60 mph. Max EOT 205, ECT 192. Largest Delta. 16.6 deg F. What do you think about Oil cooler health based on those numbers? And how does that affect coolant flush and backflush, oil cooler replacement needs?
This is really subjective. Start with a cold start, what are the readings of the ECT and EOT? Are they the same?
Lets say the EOT is 2 degrees higher than the ECT cold, that would mean you are 10 to 14 apart. My truck has been running for years 8-11 apart, been flushed, ELC coolant, new oil cooler, high flow EGR cooler, still runs 8-11. I am convinced it is normal for my engine.
How fast does the temp come down when at a stop? That is the key. Mine will cool down fairly quickly after the crest of a hill or at a stop.
Great. I don’t know the history of cooling system maintenance. I’m getting ready to drain, flush with the salt water, put in ELC coolant. Given my borderline Deltas, What are your thoughts on the flushing procedure? Oil cooler backflush? Chemical flush?
Don't worry so much about the 16F peak, the ECT can vary quickly based on engine load. When cruising down the highway steady state you'll see the numbers level out and that's your data point. Looks like 205 - 192 = 13F minus the 2F you see at startup gives you an 11F differential. Probably OK. Just keep and eye on them and if they get worse you may need an oil cooler.
Great. I don’t know the history of cooling system maintenance. I’m getting ready to drain, flush with the salt water, put in ELC coolant. Given my borderline Deltas, What are your thoughts on the flushing procedure? Oil cooler backflush? Chemical flush?
You can flush with DISTILLED water, do not do a heavy cleaner. Buy about 20 gallons of distilled, flush, drive till at temp, drain, refill repeat. Go with ELC after you are done. Check the sticky notes for full instructions.
Thanks for the help. Distilled water only flush. I’ve been reading the flushing thread with the sticky note. Can I get away with only pulling one drain plug or do I need to do both?
If you're switching over to ELC, pull both plugs for sure. The starter isn't hard to remove - if you have the exact combination of extension and socket, neither too long or too short.