I took the family down to see the eclipse last weekend and rented a 32 foot trailer to tow behind our '05 Eddie Bauer Excursion. We've had it less then a year and I know it has been rebuilt and studded, but that's about it.
On the way down I learned this engine has an added blower that kicks in at 220 degrees F. I'd never heard that kick in before, but it quickly dropped the ECT to 210 then disengaged.
On the way back, we were towing this 8000 lb. trailer up some steep grades on 197 north in Oregon in 87 degree heat. The EOT climbed as high as 248 degrees while the EOT rarely went above 220 due to the blower kicking in, according to the Scangauge II. I was pushing it pretty hard and these are steep grades; the downhill portion has a few runaway truck ramps. I was maintaining at least 50 mph uphill, and downhill the automatic engine braking worked flawlessly. A few times when I touched the brakes downhill, you could hear what sounded like the aforementioned 220 degree blower kick in as the engine shifted to slow us down. Is that the same blower or a different system? The tow/haul mode on this rig seems like it works pretty well. I'm not running any custom tune unless the previous owner did something, which I doubt. I'm running Delo 15W/40 and had fresh oil in the truck. Anything to be alarmed about with those temps?

 

First please read tech folder at the top of the post listing, get the cooling system flushed then replace the oil cooler before you melt the oil filter standpipe. I believe the noise you hear that you think is a blower is the cooling fan locking up to cool the engine. Most of all start reading because you are gambling with EOT temps that high........

 

I thought it would start to de-fuel before it got that warm?

At any rate as Bill says, time for an oil cooler. ECT temp seem plenty warm as well but not unheard of.

 

First, the roar that you heard was the fan clutch doing its job. When the coolant temp hits about 214 it will start locking up the fan clutch enough that you can hear it.
But the oil Temps should not be getting that high. It may be from a partially clogged (coolant side) oil cooler. For me, anything over 235 for oil temp would be alarming. I rarely see 220.
For an example today in the heat with AC running in a 10k truck pulling 12k+ fifth wheel camper the highest my oil temp hit was 223 going up a long hill doing 70mph 22psi boost & 1200 egt.. Most of the trip coolant was +/-205 and oil was +/-214. They fluctuated a lot today because of all the hills.

 

x3. You need a new oil cooler NOW! This is something you don't want to gamble on because it could end up hurting you in the long run with a new engine. Get a new oil cooler and flush out the cooling system immensely and throw on a coolant filter after. There are tons of procedures to flush the coolant system, but make sure you set aside atleast 1 day to completely flush the system, first with VC-9 or some other scale remover, then use simple green, followed by tap water, followed by like 50 gallons of distilled water. That is pretty similar to how I did my flush. Best of luck!

 

Sorry for the bad news, but it's a lot cheaper to fix before it grenades.

 

Mt friend you are running way too HOT!!!! Consider a new oil cooler (OEM ONLY) or if money is ok You might want to consider the Bullet proof air to oil cooler and 7.3 fan upgrade, Costly but fixes you FOREVER!


If you are handy you can install yourself...on a 5 star difficulty it is a 3-4 for sure depending on your skill level. The parts alone are close to 2k plus the added other items while you are in there depending on the year of your vehicle


One thing I have learned from owning my 6.0 for 13 years....there is only one way to fix it correctly....good luck

 

Before doing anything, I would be interested in knowing what the OP's coolant/oil delta is during the standard cooler test (ie 65 mph on the level, unloaded, for an extended run). I can get my heavy RV pretty hot on grades also (while towing) in heat, but my delta's less than 10 and I'm not worried as long as I don't exceed 240 on the oil. If it gets too warm on a very steep grade, pull over for a spell.
If you run hotter due to road conditions (grades) and towing loads, my best advice is too make absolutely sure you aren't using Ford Gold coolant.

 

Well rats. I was hoping that folks would say that wasn't unusual for towing but the consensus here seems to be that I have a problem. My normal deltas are right about 8-10. Last winter the coolant was always around 180, though this summer it runs about 190. I have no idea what kind of coolant is in there right now. I think I'll take it into a diesel shop up in Tacoma and at the very least flush the coolant. I need to have someone that knows these engines look at it anyway as I would love to know more about past work that was done on the engine. I was told I would be getting receipts t but those never materialized. It has 128,000 miles.

 

Do a little research, find a reputable shop. Yahiko might know of some around the area, his stomping grounds are close to you I think <30 miles

 

Might want to try a new thermostat and check your ECT/EOT difference again.

If you went all the way to Madras for the eclipse, then, the hills going home can get a vehicle pretty warm. The climb up to the 197-97 jct. is a long one.

 

That's the one where it got the warmest. I've read enough threads on here to know that I could expect a delta greater than 15 when towing, especially in the heat and uphill. Since the ECT was holding steady at 220 at the time, 248 didn't seem that extreme. Now I know to take it a little easier and do get some things checked out.

 

Look at the Mishimoto 203 stat.

 

Reading threads to expect a spread over 15 is one thing, but seeing over 40 is not a good thing when you are pushing 250 degrees, that is about hot enough to defuel things and start melting things. Once you have reached that point it's many times bye bye engine.
If you are not seeing over 15 driving during the normal "test" that most here use that is good, however the fact remains when towing it's not good.
Perhaps a t-stat as other mentioned is a good starting point, and go from there.

 

Oil defuel point is 253*f. So you're not quite at the melting the standpipe level at 248*, but definitely at the point of concern. Oil cooler R&R, and it'll be fine.

That doesn't mean blindly swap the cooler, the shop should also inspect the base plate for the oil filter that houses the oil cooler, there are two bypass valves that need to be inspected. One bypasses the cooler, the second bypasses the filter. The filter bypass is in the standpipe and breaks fairly easily/often, but isn't related to an oil heat issue, so that's mainly a CYA/is this to correct filter maintenance question. The cooler bypass is buried down at the bottom of the filter housing, this one will let uncooled oil past the oil cooler if pressure is too high or if the spring weakens/valve leaks. It should be removed and inspected as part of changing the oil cooler. Which at EOT being +40*, that sounds like almost certainly an oil cooler problem.