You're right of course......but if the oil cooler isn't working at "normal" efficiency, The question might be how long will it take to "clog" further? ............ and more to the point, if you're not monitoring oil temp, at what point will the oil exceed that 240-250 temp?

And how fast would it do that if pulling that big load up that big hill......like the top of Snoqualmie, (Wa) Grapevine, Grocer, (Ca) or other steep long grade etc?

Yes, most (or all) synthetics are not "damaged" by running hot, but it's not the oil I would worry about since we have an oil filter housing with a plastic part inside that literally becomes liquid when it gets hot enough.....and yes, it probably takes more than 300 degrees to that. But the time to get from 240-300 degrees could be a rapid climb if the engine was already hot to begin with and the oil cooler was already (partially) clogged!

Eliminating the EGR cooler just eliminates flash-boil and subsequent RAPID cooling system pressure-rise that would result in coolant loss (and REALLY getting the operators attention)

I am actually agreeing with you here. But the worry is that it just raises the bar on engine temps to the point that the next catastrophic problem can be just as bad (or worse ) if allowed to continue.

Using the 15 degree delta at 65MPH level/empty etc is a pretty good indicator of an IMPENDING oil cooler problem, that left alone could result in bigger problems because the "clogging" of that oil cooler is progressive. It gets progressively WORSE.

Because of this, eventually the coolant-oil temp spread would result in dangerously high oil temps.

EGR cooler or no, I think most would suggest that people still plan to replace their oil cooler if the FOMOCO "test" fails at the 15+ degrees spread.

FOMOCO could probably publish a "revised temp spread" of 20, 25 degrees etc for those engines that have had the EGR cooler removed, but they would be SPANKED severely by the EPA for advocating or providing procedures for operation without an EGR cooler..........Considering what's happened to VW, that ain't NEVER gonna happen!


Regards,


RIck

 

All true, my point was IF the bypass is stuck (even partially) open that will also lead to higher OIL temps - EVEN if the oil cooler is working properly.

Using the WRONG OIL Filter can ALSO cause the bypass to not work properly - resulting in higher OIL temps and un-filtered OIL.

 

Thanks for all of the replies. Please do not misunderstand as I really appreciate all of the info, but I am now totally confused as to what the potential problem might be. So, when I changed out the original oil cooler (circa 2010, January I believe) I also removed the stock up-pipe and the EGR cooler in an attempt to help the motor live longer. I also added a coolant filter and have been using ELC ever since. Given the coolant filter and ELC I assumed (stupid of me) there were no silicates dropping out of the anti-freeze, clogging up the oil cooler. Perhaps there was enough junk left in there from that flush to have started the demise of the cooler, don't know. But with EOC temps in proper range, and EOT's at a 30-35 degree delta towing or not, something is clearly wrong. In 120K, I have never seen this. It has only had Ford filters, so I don't know about the by-pass, but nothing has changed there, so, again, it points to the oil cooler, I think? I am open to correction here....And, with all due respect, these engines are not designed for a long life at 235 degree oil temps, sorry. gm

 

235° oil temps while towing and not constant, will not hurt a thing! They will survive a very long time! Not sure where you get your info but as stated previously, many big rigs maintain 230°+ oil temps regularly and if you read up on the newer 6.7 powerstrokes, they see oil temps in that range while towing as a normal daily thing...

Many folks blow this whole oil temp/delta thing out of proportion and have for years with these 6 liters.. take the EGR OFF, flush the junk ford gold out and put a real diesel coolant in, replace your oil cooler and be done with it!

My truck has ran consistent 20-30° deltas for years with no issues whatsoever. ELC coolant, NO EGR and a coolant filter. Thats it! Stock headgaskets, stock bolts, stock everything! 100k+ miles.

 

I wanted to stay out of this thread, but I fear there is some misinformation that needs to be corrected.

1) to the OP. Did you fix the oil leak? Are these oil temps with the proper amount of oil in the engine. If the answer to either of those is no, then do those first and test at 65 mph on flat ground after 20 minutes of driving. You really need about 2 miles of flat road to do this right.

2) The oil cooler bypass valve is a rare failure. It opens when the differential pressure between going into the oil cooler and out of the oil cooler is 25 psi or higher. When this opens, some oil bypasses the oil cooler. When the oil cooler bypass valve opens, it does NOT bypass the oil filter. There is a separate oil filter bypass valve.

3) If you have an EGR delete, the delta test in not irrelevant. It is still a good test to evaluate the performance of your oil cooler.

4) Elevated exhaust gas temps can cause elevated oil temps. This can be from a clogged Cat not clearing the exhaust and making the engine work harder for the same power.

I pushed EOTs of 245 or so when towing by 32' TT in 95 degree heat. This was on a truck with a new WP, new radiator, EGR delate, and EGR valve plugged in. I changed Tstats and bypassed my Cat, and I rarely exceed 225 EOT now. My ECTs are also lower now by about 10 degrees. I speculate the TStat, although opening around 170 degrees, never fully opened. My Cat seemed to be clear.

To the OP: I flushed my coolant system AFTER an oil cooler change only to push 20 degree deltas 5k miles later. I installed a coolant filter at the same time. Appears I pushed stuff into my new oil cooler. You could have had the same happen. How many miles since the oil cooler? And did you flush and change oil coolers before the coolant filter kit? I recommend people flush and run about 5k miles before changng oil coolers, so anything that gets loosened and lodges in the oil cooler will come out with the oil cooler swap.

 

So, I want to circle back on this issue and report what has taken place. First, I have belonged to this forum for a long, long time and the knowledge passed on here has helped me enormously in keeping my 6.0L alive and in good health. That said some of the comments really do floor me. There is a relationship between EOC and EOT with or without an EGR cooler. The fact that the EOT has been running uncharacteristicly high is an indication of a problem and if left unresolved, would at some point cause some serious damage. Waiting until the ECU takes away fuel is not, in my estimation, a way to keep your rig running well over the long run.

I took the truck to my car care provider, NW Custom Diesel in Tacoma where Matt and his team replaced the oil cooler. After replacement I did a 10K tow over the holiday and low and behold temps never exceeded 217 uphill and the spread stayed between 6-10 degrees, right where it should be.

Now, I added a coolant filter when I last replaced the oil cooler so I don't understand how the oil cooler got plugged. Perhaps I was sloppy on that first flust, I don't know, but plugged it was.

I don't know if this is the right place to do it, but if your looking for help, Matt and his team are absolutely terrific. They got me in on short notice, did the job in a day, no leaks, no issues, well done. And, a very fair price. Thanks for everyone for your comments. gm

 

So my 6.0 excursion runs right at 15 degree delta on 95 degree day. ECT will be between 190-205 and EOT between 205-217. Never not even while towing in 100 plus degree heat has the EOT gotten to 220 or higher. Is this acceptable and within allowable tolerance?

 

EOTs below 235 are fine. Ideally you want them below 230. However, the 15 degree delta should be giving you higher EOTs while towing. At you towing light or less than 100 miles or less than 70 mph? I've noticed those variables greatly affect my towing eot.

GMC, your experience is the same as mine. I changed my oil cooler and installed a coolant filter at the same time. It takes the bypass coolant filter a little bit to catch all the debris. Thus, 5k miles after I changed my oil cooler, it was plugged again.

I had just purchased the truck and the PO didn't maintain it well. The coolant system was nasty...and had never been cleaned well after an oil cooler rupture that occured one year after he had installed an egr delete without changing the oil cooler. So, yeah, oil coolers will rupture even with an egr delete. Lord knows what kind oil temps he was pushing before it ruptured.

The oil cooler is also a P-trap....a natural place to capture crap. This my recommendation to put some miles on it between a flush and a oil cooler change.

 

Just a popup camper but usually 75 mph

 

Now it makes more sense. Not enough of a tow to work the truck hard. I bet the truck barely knows it's there.

 

Exactly. It doesn't feel like it's there.

 

I'm in the same boat, I'm seeing EOT's constantly above 240 while towing my 12k lb toy hauler behind the Excursion on flat ground, and when I hit even moderate hills I've seen 250+. Over the weekend we did a family mountain bike trip up to Powder Mountain Utah, it's the steepest paved road in all of Utah...I hit 250 on the climb without anything being towed, pretty much unloaded. Thank goodness the first thing I did to my X when I purchased it less than 2 years ago was an EGR delete or I think I would have had a massive problem with these temps and a stock EGR.
It's now time to break into the motor and replace the oil cooler. I'm considering doing the BPD relocation kit to put the oil cooler where it belongs, in the front of the truck so that I never have to do this again. If anybody has done this before I'd love your honest opinion, was it worth the nearly $2000? Would you do it again, or would you just replace OEM oil coolers every 50k?

 

What's it cost to change the oil cooler? My son did tyhe BPD oil cooler and he still gets 247 temps on oil. He dose pull 16K up some pretty steep hills here in California and AZ. I'm not sold on it. I think it's not big enough for his toy hauler. He dose drive a CC LB 4x4 rasied 6 inches. It is great unloaded but that's not what he bought it for. But he dose have there BPD egr to, I think a mistake. He should of deleted it, but we have smog rules here.

 

It's interesting, the smog rules and Ford's early attempts to deal with emissions on their diesel trucks. My ride has been modified, for off-road use only of course, but has no problem with emissions. And, the northen California state of Washington uses California emission standards. While getting it tested I often wonder what has been accomplished here. Rhetorical question, but it does make one wonder......

 

Don't immediately jump to oil cooler replacement without doing some due diligence with thermostat, radiator, etc.

If you do replace the oil cooler, do a very good coolant system flush and put 1 to 2k miles on it before changing the oil cooler and put a coolant filter on it. This will help everything you loosened in your flush to lodge in the old oil cooler or coolant filter before you remove it. The oil cooler is a pea-trap.

If you can do that, then the old oil cooler will be fine for a few hundred thousand miles if you change coolant every 2 yes.

I pushed 255 eot until I changed the oil cooler and the TStat. Oil cooler dropped it to 245. TStat dropped it to 230 max with 223 average while towing.

The cat may also be plugged a little.