Plow clutch is your issue. It runs constantly and can actually cause overheating on the highway.

Josh

 

I just ran yesterday 560 miles pulling a flatbed w a 35 ford. 6k pounds roughly.

Early on it was cool ambient temps, late morning and early afternoon it was 80 degrees.

It stayed within 1-2 degrees on either side of 200. Oil temps were between 207-212.

It's holding up for me with these temps/loads.

Summer won't get a whole lot hotter but the load will go up about 1500 pounds w the travel trailer.

 

Just installed the 200 degree t/stat last week. Truck runs great and fuel mileage is up. Only issue so far is the fan clutch stays on all the time with the AC on. Turn the AC off and fan clutch goes off.

My truck has new replacement OEM fan clutch.... Not a plow fan clutch

 

I towed my boat and trailer about 75 miles each way last weekend, roughly 3500 lbs. Hardly a budge off of 202-204 ect and 210-212 eot... pulling a few fairly steep grades both temps would rise a few degrees, but it seems that at 207 ect no matter what my fan ramps up and cools it right down to 202, even on the hills.

Ambient temps around 80 degrees.

I'm very satisfied.

 

weird, I hooked up my AE software to the truck and drove it a bit on Saturday. The scan gauge showed the temps at 200 ECT and 206 EOT, the AE showed 205.25 ECT and 201.50 EOT.

I was not towing anything just cruising around 70 on the highway. Wonder why the difference in the readings. I am going to order my Edge insight gauge this week so I'll see what that says.

 

Coming home on our trip we hit the hills in the 80 weather. We held 65 on the longer straighter grades.

ECT hit 212 and held there till we crest over the top, oil was 217 then got to 221 at one point.

It cooled very quickly after the summit.

 

Weird you mention this...Andrew had the AE software on my truck and it had the ECT and EOT flipped as well.

 

Ambient temps 90 degrees. stays at 200-204 pulling an ATV and one in the bed, 70mph.

 

Ambient temp 90* cruising 73 mph running empty, my ECT ran a steady 207. EOT runs just below that (BPD oil cooler) at 204 and although not "hot" it's making everything else work a bit harder than I'd like it to. I'm going to put my OEM thermostat back in for summer and switch the MISHI back when the cold returns. Maybe I'm being a bit picky, but I just prefer a bit cooler temps for highway summer driving.

 

Little update, warm around 75-80 this past Saturday made a trip to Muncie In, from south GR, MI. cruise set on 72-73 towing a 6x12 enclosed trailer (went to move the youngest back home from college). My ECT ran 204 and the ECT was at 209, empty on the way down and loaded on way back with same numbers...

It does still scare me that it stays over 200, maybe we will see what it does towing the bronco to play this weekend.......

 

Drove to Farmville VA yesterday in 100* temps. Total trip up and back is around 300+ miles, temps ran 200-204 and EOT is at 204-207, both up and back, empty, 55-70mph with some rolling hills.

I see all the posts about being close to 210* for EOT and your worried about high temp... you guys are forgetting that the engine operates more efficiently at 210. Now maybe pulling a heavy load I'd want the temp a little lower, but if your truck is working correctly (oil cooler, fan and coolant system) you shouldn't have any worries. The increase in mileage with a little higher temps is the payoff.... my mileage is up on average 1.5-3 mpg with this t-stat. My fan isn't working any harder and neither is the cooling system.

 

I was going to mention, isn't 210 degree the sweet spot for diesel to burn?

 

Yes it is...

 

Combustion isn't taking place in the oil cooler cover, I would hope that the engineers figured out the correct temp thermostat to maintain a good combustion temp in the cylinder heads.

 

The oil being 210° isn't the problem, it's when the coolant reaches 210° the fan will ramp up to somewhere between 1400 and 1700 RPMS and start dragging mileage down.