7.3 EOT no greater than 20* higher than ECT

6.0 & 6.4 EOT no greater than 15*

Ford Service Manual. I don't have the 6.7 manuals yet.

***Also should point out the readings should be calibrated when Engine is cold to identify sending unit differences. Automatic Transmission Units can not be calibrated as the ECT does not report correctly to PCM until 130* ECT on 7.3's

 

I got the formulas from your Torque Pro thread. I'll pull my AE and run it tomorrow to measure the difference.

 

I can't read the ECT without a separate gauge, as the PCM doesn't read it.

 

I use a laser thermometer on the thermostat housing to get that reading. The laser thermometer is an essential tool on anything to do with vehicles anyway - check brake rotors, bearings, manifolds, coolant, etc....

 

Yep, I've done that and get the same 200* readings so my truck runs warm... The Excursion is just like a woman, never tells you what's really happening under the hood.

 

I wouldn't waste my time with swapping out to a 205 t-stat. Not once have I ever been in a truck with one and gone "wow, I can tell a difference".

Plus looking at the tuning aspect.... timing, ICP, and fueling wouldn't change until your engine starts to overheat. So adding a t-stat that rated for 10 degrees higher than stock won't change anything on the tuning end unless it causes issues with your truck maintaining proper temps. At that point you would have other problems.

The stock VDH5 calibration doesn't change injection timing offset until EOT reaches 260 degrees. That's just one example.

So far I haven't seen dyno pulls and emissions results between the two that would convince me otherwise.

 

It's not. Really your's isn't any different than anyone else.

EOT will change dramatically during a drive cycle, depending on conditions, speed RPM, load, and a host of other things.

Since 2009 to now I've learned that. Things change. Back in 2009 I was just starting to get into the electronics side of these engines. I hadn't done enough data logging back then when I made my first post in this thread to give an accurate enough feedback.

Now I can tell you after having far more "practice" that my truck and most other trucks I've data logged see the same temps you are seeing.

 

I checked mine yesterday it was 75F and I had an oil temperature of 210F at 65mph with my winter cover on. When I pulled it off it dropped to 200F.

 

While we're on the subject, I have a question:

Towing home from Moab yesterday (8000lb Excursion, 7000lb trailer) I was seeing oil temps in the low 200* range on a 70-80* day. No problem. Climbing eastbound Vail Pass at 60-65mph, I saw a high in the 230's. No problem.

However, climbing eastbound toward the Eisenhower/Johnson tunnels at 60-65mph, my oil temp hit 253*. That seems like a problem. The stock coolant temp gauge moved to the middle by the top of the climb, and the fan clutch is pretty new, and worked fine. This is a tough 10 minute climb, with the EGT's bouncing off 1300* the whole way, and tops out over 11000ft.

Do I need to be looking for a problem - clogged radiator, perhaps - or is this normal? It never used to happen, but I may have just modded the truck enough that I can now push it harder than in the past.

Mark

 

Thought I'd bring this up again. Headed up Mt. Vernon canyon (climbing westbound on I70 out of Denver), with the same trailer, my oil temps hit 252* Friday afternoon on an 85* day. (As measured with Torque, so that's the temp the PCM saw.) Coolant temp gauge on the dash went up to about 2/3, but returned to it's normal position just after cresting the hill.

Is this a problem? Not a problem? As I mentioned in May, this didn't used to happen, but then I didn't used to be able to pull the speed limit on climbs like this when towing, and now I can.


Mark

 

Mark, you admit you are pulling a load, running up a steep incline, at high elevation--you are driving a light truck, not a semi,which does show up in the exhaust temp. Exhaust temp and oil temp do reflect the work load put on the engine. The closer you approach the practical limit of your engine (and the design limits), the higher those temps are going to be. If you want to reduce those temps with your mods still in place and still drive fast up high mountains, you need to get rid of the heat. Much bigger oil cooler(s), larger intake, exhaust, etc. There are vendors out there that will gladly help you spend your dollars to do just that.


Larry

 

Not once have I ever seen my temp gauge on the dash even budge at all.

The only time I've ever seen a temp gauge rise like that on any 7.3L is when there's been a problem with the cooling system. Not trying to sound alarmist, but there's a possibility you might be seeing the first signs of something. Could be water pump (most common), or something else.

 

In this event, my first act would have been to slow down until I could pull into a safe place to stop. I would then grab my hand-held temperature sensor and confirm the readings. It's possible Torque had a brain fart or a flaw in my formula - hence double-checking. If the temperature was confirmed, I'd continue on (after allowing to cool) with the A/C off (windows down) and drive as needed to keep the temps 220 or below.


You may need some mods to the cooling system to keep those speeds - or you could have a mechanical problem. How were your EGTs?

 

Here's a thought, and I might be completely off the reservation on this one but, with a steep incline, combined with the tongue weight on a bumper pull trailer with 7K pulling you backwards.......would the angle of the engine (incline + weight on the hitch) be enough to provide a an impact on coolant flow through the engine to the radiator?

With a pump that is possibly less than 100% it might be enough of a perfect storm to show the flaws in the existing system not being at 100%.....

And I believe you said it was more pronounced in a long tunnel? If so, is the engine breathing in some sub-optimized air?

Again I could be barking up a completely wrong tree......

 

I read your original reply on my phone. It was fine , and I don't disagree. I'm wondering if I've got a marginally performing cooling system element that's allowing temps to get a little higher than desired.


Curtis, that's how mine was for a number of years. The needle might as well have been painted on the dash. I think - but am not sure - that the coolant temp gauge stays put until EOT's get to be about 240*. I never monitored oil temps 'till Torque made it trivially easy. I do remember Jody mentioning high oil temps to me on a live tuning run up Mt. Vernon canyon, also on a warm September afternoon. I think he said he was seeing 240*, but I'd never seen my ECT gauge move at that point.

The water pump, bottle, hoses and cap were all replaced with OEM parts in 2010 (a month before that live tuning run), but that was only 23K miles ago. Not that any of those couldn't be the problem, but if I throw money at something, I'm thinking radiator and/or oil cooler.

You've looked at a bunch of trucks in CO, so I'm interested in your thoughts as to what EOT I should be seeing as a max in these situations?

EGT's on these long climbs are pretty easy to control. A max of 1200* at the lower elevations (<8000ft). I do have to drive by the EGT gauge up high, but even then I can keep them at 1200-1250* and maintain a reasonable speed.

This whole thing "could be a question of air flow", to paraphrase a popular commercial... CO is a front license plate state, so that blocks flow a little. I have a couple of PIAA lights that have been on the truck for a dozen years, and they block a little more. I'll pull them off before I tow again.

Mark