Hi Everyone,

Need to get some opinions here on my deltas towing last week. My Excursion is a 2005 with the head gaskets/studs/oil cooler/ egr delete done at 190 000 miles. I also run a 203 Mishimoto thermostat and use Shell ELC coolant. The only thing I regret not doing at the time was a complete coolant flush- I was still very much a newbie with getting used to a 6.0 PSD. I did do the HG myself with the cab on though. Glad I did it myself as my knowledge grew by leaps and bounds.
I run a mild Tony Wildman tune with the SCT3 programmer.

Normal highway driving temps at 60 MPH/ outdoor temp 38 F for 30 minutes are 195.8ECT and 204.3 EOT. I do find it strange that the coolant temps are ranging from 195.8 to 197.6. Could my coolant temp sensor be getting weak? My ECT normally sits at 195.9 to 199.-I thought it would be closer to 203.
Does everyone else find the temp bouncing around? I did notice a TINY amount of coolant in the snow and noticed a few drops of coolant around the EGR bypass pipe that threads into the intake manifold. It may have been the blue hose on the pipe leaking slightly as well.
The ECT and EOT cold soak temperatures are within 2.0 degrees of each other.

Ex currently has 228000 miles and towed a 6500 pound trailer to the cottage. Temps driving up were 14 F and on the way back were 35 F. Trip was 7 hours each way with the average speed 60-75 MPH.
I run a Torque Pro app on a 10” tablet which is great for info.
When towing do you see a farther delta than normal highway driving? My ranged from an average of 11 degrees to a high of 16. I was surprised at this difference.
The funny thing is that I did an oil change two weeks ago and for some reason my oil temp “seemed” to be 2 degrees higher with nothing else being different- I always use T6 5W40 and a Ford oil filter. Could my oil temp sensor be going erratic?

Should I be concerned with these deltas? Most of the time it is a daily driver. My worry is that they will be worse come summer and 90 F temperatures. I know that it isn’t past the magical 15 degree delta but it seems to be a lot closer to 15 than I would have figured on. Should I be getting ready to do a oil cooler replacement in the next year or so?

Any input is appreciated.

Rob

 

You said those temps were just driving down the road, is that with the trailer or without?
They are definitely high without. I'm at like 189 ect and within 5 degrees eot unless its crazy hot running ac in bumper to bumper, I'm hammering it, I'm climbing a hill, or I'm towing.
Now, I've had several coolant leaks over the years including a heater hose that rubbed through, a cracked degas tank and a leaking blue hose on egr delete. The coolant temps would range 198 ish up to 210 and spike even higher while towing up hills because the coolant system needs to be pressurized to work correctly. Any leak is bleeding away pressure and diminishing cooling capacity, is my understanding and experience.
If you're seeing even small leaks you need to find em and fix em.
Towing I'm usually within 15 degrees unless I've just climbing a very long/steep pass and the coolant temps will drop quicker than oil but within 5 minutes or so they will drop back to normal. When I had coolant leaks I was seeing coolant temps of 225 or higher. Not good.

 

Ever since I did my coolant flush and oil cooler my 05 would have a 8 degree ish delta at 70mph not towing. I believe mine is a bit higher than some because of it pushing 35" tires. Towing I will see deltas of around 10-15 depending on what I'm pulling,hills, ambient temps and such. Also all my temps and deltas will jump around a few degrees also. So I'd say yours is right inline with mine anyways.

 

Moved over to the 6.0L forum for you.

Stewart

 

I don't see anything wrong. I'd expect those ambient a to drag down ECT temp regardless of thermostat. Also, the thermostat is not a precise temperature control device.

Ive seen deltas towing my 8K travel trailer that are surprisingly close to my typical 10 F delta. If the ambient is above 65 F, I will see the fan come on at 207 ECT, and that can make the delta calc a little squirrelly.

 

At 65mph, unloaded, all accesories turned off, flat ground, after 20+ minutes, are are seeing deltas higher than 15 degrees, it is time for an oil cooler. That is the case when stock. With the egr cooler deleted, you can stretch that a bit, but beware when oil temps exceed 240f.

As someone else said, address the coolant leak(s) first.
Any puking out of the degas bottle when filled to the cold min. line? The old cold min line is the new cold max line. Filling it higher than that can make it puke under load, even with a healthy cooling system and engine. If the degas bottle cap is old, replace it anyway for cheap insurance.

Also, keep in mind that towing will yield hogher deltas. Don't worry about towing deltas unless they become severe. You would see excessive unloaded deltas as well in this case.

 

Thanks everyone,

At 65 my deltas are anywhere from 7-9 degrees depending where the coolant temp sensor decides to say.

I will address the coolant leaks soon as well. My truck has not done any puking out of the degas bottle at all and my degas cap( Ford replacement ) is only a year or so old too.

 

Other than the coolant leaks, I'm not seeing an issue here. Your coolant temp seems a bit low considering the mishimoto t-stat, but still higher than OEM. I wouldn't worry about it until it won't hold 190f.

 

Temps will go high and delta can reach 25F on hard pulls in 100+f but down shifting and easing up on the pedal til fan come's on full will take care of it. If temps continue to climb and delta stays at or above 25f while the fan continue's roaring you might be on the way to problems. I've seen high 230s eot w/25f delta while pulling hard long hills on hot days since new but soon as fan open's up full bore they begin dropping. Use tow haul in the mountains,the added rpms are not only easier on the drive train,temps are more stable and there's less fan locking.

 

My deltas never change from towing or empty except during cool down. Always 10-12, with coolant running 190 empty and up to 215 towing.

 

At 65mph in my truck with 4.88 gears, you can bet i'd have high delta's as i'm spinning it at roughly 2500rpm. Using a specific mph isn't a good way to do this.

To the OP ... number's look good IMO

I think people get hung up on the "delta" and don't actually look at the numbers. Your EOT is only 204. The acceptable normal range is 200-230. Your more than good.

 

Thanks everyone for the quick responses.
I will be sure to fix the coolant leak(s) in the very near future and will keep an eye on things in the meantime.
I also found a new temp sensor in the shop and I think I will replace the coolant one to see if the ECT temps go up slightly to the supposed 203 thermostat.

Rob

 

You're right about the gearing and rpm. Most people have trucks with 3.73 gears and that is what the test is based off of. In reality, you want 1800-2000rpm in your tallest gear. 2000rpm would be the minimum with 4.88s, since the unloaded "load" would be less.