Yes Sir X1000^^^^^^^^^^^^

Just Hate to see thing go from BAD to Worse on ya

 

I really appreciate all of the feedback. I have a solid understanding of the condition of my oil cooler. I keep one eye on the road and the other on the my scangauge 2. I've never done more subtraction in my intire life now that I own a 6.0l calculating the Delta every 5 seconds.

Just for fun let me ask you guys what your ideal theoretical fluid temps would be if you could pick that perfect temperature. Let's say this is at level freeway speeds and we're all running Rotella T6. Going way off topic my 2004 Cadillac CTSV runs all day and night with an EOT of 235f and it has almost 200k miles on it.

 

Very well said Bismic!

 

It's not the 235F oil temperature per se...it's the ECT/EOT delta that you are experiencing that points to diminished coolant flow through the oil cooler (in series with the EGR cooler). This puts your EGR cooler at risk of failure, and that can lead to a lot more expensive problems.

 

Actuallly in my opinion it is the oil tempature. When you start the truck ECT slowly increases (or quickly) till you get to 190 then the thermostat tries to regulate tempature. (This must be optimum temp) With a brand new oil cooler (like mine is... OEM coolers btw) you get a delta of 3. Now the TSB from Ford says Maxium of 15 degrees spread after which you replace cooler. That makes optimum oil temp max 205. Now if towing or giving truck a workout coolant reaches 220 (or thereabouts) ECT the fan kicks into overdrive to drive coolants temps down to avoid boiling of coolant. If we take into account the 15 degree spread max (ford TSB) our oil temp is now 235. As you can see Ford designed this truck to operate between 193 oil temp and about 235.

Now keeping in mind what the oil does and the nature of oil and we come up with why (atleast some of them). Oil is thick when it is cool. As it warms up it thins (hence why the thermostat doesn't kick on till 190 we want the oil warm so it flows freely). Now as oil heats up past a certain temp (not sure the temp) it starts to cook (break down) the hotter it is the quicker it breaks down. This is why we do oil changes. We change the oil to replace any cooked oil with fresh oil This is also why Ford has a different oil change regimium for Severe service. Under severe service the oil breaking down faster so we have to change it more often.

I would say that if you are going to IGNORE Ford and the FTE who post here when they say the oil cooler is comprimised and to change it.... atleast do your poor truck a favor and change the oil more often...

 

Shiny new oil cooler and EGR cooler (two weeks old), lots of flushing before the work was done, fresh ELC, new thermostat, almost 100* outside, truck has 144K mi. Rock solid temps on the flats at 70 mph is 196ect/ 198eot. Highest I've seen is 200/205 on hills. Lookin forward to towing the 5r and see what it does!

 

Ford has dealt with so many late model EGR cooler failures that they instituted this delta as a way to determine restricted coolant flow to the EGR cooler (which weakens the coolers construction due to the heat, and causes failure). Our engines do not de-rate until 253 degrees F on the oil temp. Not that I would be happy to run that way, but oil temps in the 235 *F range (and even higher) is fine (as far as the oil itself goes) - especially if synthetic is used. There is some point at which the oil cooler itself will fail (happens a lot!). One thing so many people just don't seem to "get" is that fluid and equipment "skin temperatures" are quite a bit higher than the measured bulk fluid temps. The skin temps (localized maximum temps) are what stress equipment (expansion of metal causes stress cracking).

This thread is why I I am getting less prone to suggesting that buying used vehicles is a good idea. Almost every one of them I have helped folks look at have failed EGR coolers or the oil cooler has already failed - just weren't properly taken care of.

 

I agree Mark. If someone asks me about a 6.0 they're looking at, I can't help but consider if they are likely to keep it up. I also assume it has some sort of problem before I even hear the details. It shouldn't be like that.
In my case, this is my first diesel pick-up. Just by luck it was in pretty good shape. After reading ALOT here at FTE, I felt reasonably knowledgable and have a decent budget to stay on top of the issues. After changing the oil and fuel filters, and getting to know the truck a bit, I put a coolant filter on it. When I dropped a few gallons for the install there was some sand in the bucket and I recognized the smell of old "skunked" coolant but I poured it right back in there anyway (for now, I told myself). Next came the ScanGauge and a few months of fooling with that. I saw my temp spread was high. (oh yea, my coolant ain't great, i need to change it) The truck would start quick in the cold temps we were seeing then, but idled pretty rough, low power, late shifts etc when it was cold so I get distracted with the blue spring and Rev-x. Then I noticed the trans temp was a little high when towing, changed the filter and 1/2 the fluid (somthing else I was going to do?). Then -two years after buying the truck- I'm @ 70 mph on the flats, unloaded, glance over at the ScanGauge and see somthing like 205/223 (damn! coolant, I was going to change the coolant!)!
I guess my point is just knowing what needs to be done don't mean it's gonna happen. It's easy to put things off or ignore them and many owners still think "it's a diesel, it will be fine, I'll get it later". That just don't work anymore. And to make matters worse, one component failure takes out other things and what could have been a $200 repair costs $1k or more. At this point many would say "this truck is a piece of crap, I'm selling it".
To finish my story, I flushed (with chemicals and Fumoto valves) and put ELC in it. Two mornings later I got a huge cloud of white smoke shortly after start-up. Parked the truck and several bucks and hours later (did the work myself) I'm back on the road and happy that I didn't lift the heads!
My 6.0 has taught me a lesson I hope I don't soon forget.

 

There is a lot in what you say. On the other hand I just bought my 6.0 less than 6 months ago. Since then thanks to the knowledge on this forum I bought a scan guage... to find out my delta was high. Replaced EGR cooler, oil cooler. Replaced EGR Cooler, Oil Cooler. I have put a coolant filter on it. I already replaced both batteries. I replaced front shocks and up links. I also run Diesel Kleen with cetane boost with every fillup. I have checked FICM voltage. I plan on getting a blue spring upgrage and doing a tranny flush. I NEVER plan on tuning it. Anyways my point is some of us "NEW" owners are learning from you and would rather let the IDIOTS learn the hard lessons (and eventually sell the truck cussing out ford and the 6.0L) than learn them myself BTW Rusty thanks for blowing up the truck so I don't have to Hopefully I can catch up on previous owners maintenance faster than the neglect damages the truck. In reality I blame and thank my DAD. Since he is a ASE certified Master technician we NEVER had a new car in my life.... I watched him get a car and then change ALL the fluids and do a bunch of other things. EVERY time we got a new car.

 

No question this forum is outstanding, and the info that is shared by
everyone is very welcome and appreciated.

Any used vehicle is gonna need maintenance and minor things fixed.
I was the original owner on my '97 Tahoe which I traded for my Ex in 2010.
During it's 197k miles I replaced LOTS of major components - some twice.
The Ex with the PSD is a great package and it's uniqueness
and "the need to do maintenance - right" is an incentive to do many
of the mods myself - with the help from FTE I'm (almost) willing to
tackle anything!

I plan to keep my Ex for many many years and as such, I'm willing/interested in upgrades/solutions that add to the enjoyment -
and/or remove some of the concerns..
The 15* delta doesn't mean you *have* damage (yet) - just you have
restricted coolant flow to the EGR Cooler. You might go 6 days, 6 weeks,
or even years before anything "bad" happens. I budgeted for the
complete BPD solution and had them installed when it was convenient.
I considered the difference in cost to replace with stock Oil cooler &
EGR cooler and then having to worry about them
everytime I flushed my coolant again.

The bottom-line, prioritize the things you want/need to be done
and keep working away at the list. Also having the right tools
makes every job SO much easier.

 

I appreciate everyones input about my oil cooler, sorry we got so far off topic from coolant levels in the degas bottle.

I'm going to do a recirculating chemical back flush soon, then if that has no effect I'll replace the coolers.

Now I have this crazy idea I probably wont try but just for fun which is to reroute the oil cooler and EGR cooler coolant circuit. Like this:

Instead of the oil cooler coolant going to the EGR cooler have it go straight to the Y under the degas bottle. Then the heater return line would go to the EGR cooler. My heater valve doesn't work so it's not a factor. Thoughts.

 

So that is normal when that happens

 

what's not normal is resurrecting 10-year old threads and elevating them to the top of the active topics list without adding something of value to the conversation. Just sayin' :-) Welcome to FTE!