That last flush should have been distilled, not hose water as you realized. Then straight concentrate coolant 3.5 gallons, top with a 1/2 gallon of distilled will get you close to 50/50 mix. Watch your ECT/EOT spread, flushing with distilled will still probably get some loosened up crud flowing (not like a chemical flush would), but maybe a couple degrees change.

 

One of the main reasons why so many recomend pulling the block drain plugs as well as the radiator drain valve. There are so many nooks and crannys in the coolant system it is difficult to get all the water/coolant out.

 

I wrote this in another Forums response.

The oil heat exchanger (cooler) responsibility is to remove heat from the oil to the coolant. However, it is in series with the EGR cooler and next the coolant cools the EGR gases. We, and Ford, use the difference in coolant to oil temperature (Delta) to tell how well the oil cooler is working. If the flow of coolant is restricted in the oil cooler, the oil temp under certain conditions will exceed 15F, the point of concern that too little water is flowing to the EGR cooler and its temperature will rise to the point of the EGR internal separation. That allows coolant into the air intake and possible damage to the engine.

Since the design is heat energy removed from the oil to the coolant (and EGR gasses), when the coolant flow is restricted less energy goes into the coolant and the temperature of the coolant will also read lower, such as the 182-185F you are reading. I would not be worrying about the thermostat being at fault here, it just the coolant not being tasked with as much heat energy. New oil cooler, more coolant flow to absorb heat from the oil. Coolant temp goes up and oil temp goes down.

 

Im gonna do a oil change in a few weeks and ill flush the radiator again. This time properly. Is the VC9 good to assist the flush?

 

Is it possible to save the cooler with a few flushes and additives to assist the flush?

 

toomanytoys - you bring up a good point about the coolant temp being lower.

Juan - It is possible you can partially unblock the oil cooler, but it isn't very likely. I would still do the flush with the intention of still having to replace the oil cooler. If you do the flush and then drive it around to find your temps a lot closer, then the oil cooler can wait. Flushing with chemicals, in an attempt to dislodge any crud in your cooling system can actually clog up the oil cooler even more, but you will have a cleaner system to start with when you put the new cooler in there. The last thing you want to do is put a new oil cooler in a dirty system, only for it to get clogged too.

 

Its a very low success rate because as you are dislodging the rust scale and silicate deposits with the two types of chemicals the flow of coolant through the oil cooler deposits more of these in this very efficient filter.

I'll come back to this later when I have more time.

 

Thanks for all of your advice and assistance.

What are normal operating temps?

What is the proper way to check delta? While driving? In traffic?

 

IMHO the proper ect is 194 to 204. Temp spread should be no more than 15 when the truck is thoroughly heat soaked, app. 15 to 20 highway miles, driving between 60 and 65 on flat ground for at least 2 to 3 miles. Climbing, cresting or down hill will not be valid conditions.

 

With a Ford t-stat 192 for coolant, anything up to 15 degree spread for oil temp. Anything above 15 is recommended to change the oil cooler due to possibility to rupture the EGR cooler. Reduced coolant flow thru the oil cooler makes EGR cooler hotter as the coolant goes from the oil cooler to the EGR cooler and back thru the radiator.

Fully warmed up coolant temps, 65 MPH on flat ground for 15 minutes unloaded. Should get you a spread of 15 or less ECT-EOT and can even go a bit more (25) for an EGR deleted truck. Towing becomes an issue much higher.

At 235 oil temp, the fan should kick into high gear, truck de-fuels and 253 or higher is bad. Several threads about hot trucks 350+ and melted plastic parts like oil stand pipe for the filter.

 

Ok. Well I tried the test and within 2 miles I was already over the delta 15 degrees.

I got a quote from a reputable shop for $950 a new oil cooler installed. Is this a good price?

 

If your in that deep... oil cooler, EGR cooler if not deleted or the actual delete kit, STC fitting, Stand pipes, dummy plugs, blue spring kit AND a very good chemical flush of the cooling system before the new oil cooler or it will plug again! Go back with ELC coolant also.

Better make sure they know what there doing or they will kill your wallet and possibly your truck!

 

I'm gonna get it all done at once because I also have a hot no start condition and I really baby my truck and I don't plan on putting a tuner.

Should I replace the degas/resevoir as well?

 

Unless the Degus is cracked , just wash it out with simple green and rinse real good , you will be amazed how much crud will come out, also make sure the cap has been upgraded.

 

I have an even more embarrassing question. Im starting to think my egr was not deleted. Does anyone have a before and after pic of what I should be looking at. Im a total novice. When it comes to diesel and I took the previous owners word.