I've been reading about temp differance between oil and coolant. I have an 04 F-350DRW 6.0 that I decided to try running the 65 MPH run for 20 miles. I have an Edge Insight that I'm using to monitor temps with. What I did was run for 20 mies at 65, light rain, air intake temp was 64, ECT was running 198 to 204, EOT was running 204 to 221. Ford oil filter, T6 5W-40 synthetic oil 200 miles ago, fuel filters Ford at the same time. I'm thinking reverse flush cooling system, possible BPD EGR replacement or deleat, maybe and oil cooler, not sure about head studs and HPOP. Funds are limited, I feel that I can do the work. Looking for thoughts from those that have been there and done that.

 

I would say your oil cooler is plugging up, but you have time to accumulate parts over time. Do you have the round EGR cooler? If so, you shouldn't have to worry there unless you want to delete it...

Replacing the oil cooler isn't hard, but will likely take a full day if you haven't done it before...

 

Personally I would flush, install a oem oil cooler and add a coolant filter. refill with cat ec1.

 

I also would worry about head studs and hpop when it's a problem.

 

Shaneb75

Why do you say that if I have the round EGR cooler its better than the square?

 

Given your user name I'm guessing your truck is an '04? Mid year 2004 there were some significant changes to the engine, generally if your ICP is behind the turbo with the IPR its an early engine, if it's on the passenger side valve cover it a late production. It's pretty important to know which you have as there were many changes and ordering the wrong part can cause expensive issues.

The EGR cooler on the early trucks were round and inside it's made of several small stainless steel tubes. Late build trucks (and through the end of production) had a cooler with a interior design like a radiator or heater core. Thin, flat tubes with wavy delicate cooling fins between the tubes. These coolers were squarish on the outside (flat sides-rounded corners). The early coolers are physically stronger and much less likely to leak coolant if they are overheated.

Fortunately, if you have a later truck, there are aftermarket companies cutting open the later style cooler and rebuilding the inside using the earlier tube design. Although it's difficult to tell its modified by looking at them, the big name, modified coolers are 50 state legal and have a CARB approval number if emission inspections are important in your area.

 

Looking back at your first post, I'd say there's not enough information to tell for sure. It's hard to describe online here but it looks like you were either speeding up and slowing down or pulling some hills while monitoring. As you apply throttle, ECT rises first and after you lift coolant can drop but EOT is just beginning to rise so thing are all over the place. What your looking for is one number for ect and one number for EOT, noted when things have settled down on a flat piece of road.

As with most things Ford, the 15° max figure for the difference is probably a bit conservative. Some trucks have a difference of 10°-15° for years and don't rise. With a tight budget, I'd monitor it for a while, if your temp spread is 13° or more maybe do a flush and put some fresh coolant in it. You'll be watching for it to be slowly rising over time. You may have time to save up some $$ to do the repairs properly instead of doing it in the "economy" mode.

The work of replacing the oil cooler isn't too bad. It's pretty uncomfortable laying over the font of the truck and there are some fasteners that will make you scratch your head as to how they got in there in the first place but overall pretty straight foreward. For the average home mechanic, maybe a day and a half on your first one and a day if you have experience. I spent much longer on mine but I cleaned and polished stuff as I went, drank a few beers with the tunes going, friends stopping by etc.

It's pretty stale but has a lot of pictures, here's a link to the thread I posted when I did my own truck awhile back: https://www.ford-trucks.com/forums/1...more-pics.html

 

As always, Rusty has done a great job detailing everything out!

I am somewhat familiar with the Spiro area and there are some hills, but nothing all that steep...

 

Rusty is giving you some good information. I'm in the same situation with my '04 having installed a Scan gauge and monitoring the EOT/ECT over the next couple of months. I'd suggest reading and gathering as much knowledge from those who have been where we are. It's vital to making the right decision for your truck. Unless your truck is showing some of the critical signs of oil cooler/EGR cooler failure...coolant loss, white exhaust, over pressure in the degass bottle, follow what Rusty is saying.

The Tech folder is a great place to start. It's loaded with vital information. Good luck and keep posting.

 

FWIW if your going to do a flush I would just use water and no chemical unless you are planing on replacing oil cooler. I decided to flush my 05 and swap to Cat ELC. Things started out good and was amazed at the goo that the Ford Gold coolant has in it. Flushed with tons of water and refilled with new coolant and distilled water. Took truck for an hour run then set cruse to 60mph and let it run for 20 mins went from a 10* delta to a 24* delta. Needless to say a new oil cooler was ordered along with studs, dummy plugs and stand pipes. Didn't order a coolant filter which I found out two years latter was a mistake. Ended up with a second oil cooler stopped up.