So I am ordering a coolant filtration kit sometime soon and gonna install it, but while I was at it someone recommended to flush the old coolant then put new in. I have a few questions for the guys who know better then myself about doing it. First of all what I have read on the internet I chose Zerex CATEC-1 coolant (is this good to use in a 6.0l)? Next I decided to read up on the flush a little bit and found that often when you flush the system that after words your oil cooler will get clogged. SOOO I found one article that said in order to prevent this you can back flush the oil cooler somehow with a garden hose, can anybody clear up how this is done? The same article said that you need to check you EOT before and after the flush???? What the hell is EOT and how do you check it? Next question is I have read many opinions on whether or not to use flushing chemicals when flushing, is this a thing I should do? and if so what is the best kind? Thanks for all the help, I am 19 and trying to do this the right way and learn myself. I have been fairly mechanically inclined (grew up working on a ranch around farm equipment) but since I have owned this pickup it is a whole new ball game, so I just want to learn from the best. Thanks for all of the help guys!

 

ECT= Engine Coolant Temperature// EOT= Engine Oil Temperature

These values need to be checked to know the condition of the oil cooler. As long as these temps do not exceed 15* with the truck at normal operating temp your oil cooler is "good" (not clogged). Using a Scangauge II or other device is the easiest way to check these numbers. I use an Edge Insight CTS since it plugs into the OBD-II port.

I for one prefer the Fleetrite ELC sold by International but any ELC should work fine. IF you find your temp split (delta) to be under 15* I would not use chemicals. If the split is greater than 15* you need a new oil cooler so hold off on flushing till you are ready to do the work.

RECAP: Get a device to check the EOT/ECT temp split. IF there is a high split, flush with chemicals, replace oil cooler and fill with the ELC. IF the split is low just flush with water, use ELC and install the coolant filter kit.

 

Ok that clears it up a lot, and fyi I felt like a dumbass lastnight I was laying in bed after posting this and it felt like someone slapped me in the face and said EOT stands for Engine Oil Temperature So if the two (Engine coolant and engine oil temperature have a difference of 15 or greater my oil cooler is clogged) which makes sense because I remembered seing someone talk about Delta and I know that means the difference but I didn't know that is was the difference between coolant and oil temperature. I have an edge evolution that I just use for reading some of the data's like that, (someone just gave it to me and I turned it up for awhile and started going through injectors like underwear). SO I will check today if that will give me EOT and ECT. If my difference is less then 15 would you still recommend back flushing the coolant for safe measures? Again thanks for all the help! Sorry for many of the dumb questions

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So I set my EDGE evolution to dislplay EOT and ECT. When I was just cruising in town and on the highway the EOT would usually be about 8 degrees greater then the ECT. I got on the interstate in tow haul mode and drove out to Utah, I always kept the speed over 80, so my rpms were usually about 2100-2200. Driving like this it would usually stay a about a 12 degree difference although the way back driving into the wind the ECT cooled down quite bit ofcourse and at one time there was a 17 degree difference, although I would not stay that way for long. SO from what I understand my oil cooler should still be good and I can flush with just water, would anyone still recommend nac flushing theoil cooler or is that necessary?