I have about resigned to a 9-10 degree spread after this weekend. Two years ago I installed coolant filtration and an external IPR cooler system, I had a constant 9-10 degree spread. Because of the system having oil seeps and not using the factory filter I decided to try going back to the OEM setup.


This past week I distilled flushed the system, removed the IPR system (except for the coolant filter), installed an OEM oil cooler, XDP steel impeller water pump, Mishimoto plastic radiator, kept my Mishimoto high temp thermostat, kept my IPR high flow egr cooler, new Degas bottle, belt and radiator hose. I refilled the system with Rotella ELC. With the exception of an egr cooler exhaust leak and a heater hose o-ring leak everything went fine and she fired up. I test drove it and back to 9-10 degree differences but the oil temp comes down faster now.


About the o-ring, it actually disintegrated and fell into the heater hose outlet in the front cover, hopefully it gets trapped in a heater core passage, there was no way to get it out.


Could it be some 6.0L engines run a different delta than others? I don't know what else I can do to get the deltas closer. Any suggestions or leave it alone?

 

Mine has run 6-8 spread even 10 sometimes since I changed the oil cooler. I figure it's my base line. I'll know it's plugging up when those numbers climb. Did you check them after a cold soak and see how close they are?

 

Yes, my cold soak is dead even.

 

Mine has run 10-12* delta for 50,000 miles towing or empty, don't sweat it, watch for changes. It was 20* and climbing at 60 mph when I bought the truck.

 

Mine is about 8 to 10. I don't sweat it.

 

Mine was 12 when I bought it. Flushed the system, deleted EGR cooler and replaced oil cooler just to see 12 degree deltas again. I'm not worried about it. It cools down almost immediately and I have a feeling that this is due to the inability of the thermostat to maintain 190 degrees. Some days my coolant temp actually gets to 193. My delta then is usually 6-8 degrees. When the coolant wont pass 188, I'll see deltas of 11-13. It's all relative. I have a feeling that if I went to the Mishimoto 200 degree t-stat, my deltas would be near 3.

 

Like I said in one of your previous posts, my stays at 9-10 doing 60-65 on flat ground. 11-13 doing 70-80 mph on flat ground. No worries.

I think you have a slight case of 6ohPhobia. I know I used to sometimes lose sleep over my first 6oh that was a 2004 .

Second time around, no more sleep problems.

I will repeat again, I think your fine. Now go enjoy that 6oh!!!!

- Preston

 

I drove the Ex today on my 50+ mile commute to the city, the delta ranged from 7-10 so I am happy plus all of your posts help. My main concern is towing season starts soon and I want the Ex to be it top shape. The lie-o-meter says I got 21.2 this morning in hwy/city combo driving. She wants to run like a scalded dog now so I did something right.

 

Ive been wondering the same thing since I bought my truck a few weeks ago! My deltas are 8-10 degrees, and I wasnt "worried" but I wasnt completely happy.
Feeling much better now that you all have said the same thing.
Just gotta wait till Florida summers roll around and see if the cooling system can still be good

 

8-10 is good in my book, if it starts going to 12 save up for a cooler or look for a good buy on one and put it on the shelf so you have it in stock when the time comes. Coolant filter helps out too. I found my delta spread lowered and stayed more stable with the Mishimoto high temp t stat.

 

Haha

Glad to hear your more at ease.

 

I'm another 8'er. I bought mine with 93k miles. At 158k now. Pretty much averaging 8* diffs since I bought. Sometimes a tad more, sometimes a tad less. Enjoy it.

 

I had the same sickness last year. I worried myself to sleep over 12-15 degree deltas. I thought about the problem all my waking hours. Spent more time reading about 6.0 problems than I did with my kids and wife.

I replaced the oil and EGR coolers more for peace of mind. I sleep better at night and the romance is back in our marriage!

It runs 4-6 degrees difference now at all times. Van runs the same.

My biggest problem now is the leaky IPR coolant filter shut off valves. I am too lazy to install new valves as it barely drips.

 

There are some that have run 12 to 14 for years and it never got higher. As others said, watch for change.

 

This is just my opinion-having a 10-15 spread is probably not as big of a deal as most think it is. The cooling system is meant to keep things cool. As long as the EOT and ECT are in specification, we probably need not worry.

I think a Mishimoto high temperature thermostat would have helped ease my mind as keeping the EOT & ECT at 205 may be easier ( I have no data to prove this) on the cooling system than keeping it at 190 degrees. I worry and over think too much.