Cooling or transmission problem ahead?
Thread Starter
|
4wd High
Joined: Aug 2025
Posts: 9
Likes: 1
From: Colorado Springs
Cooling or transmission problem ahead?
I have a 2025 with 6.7L Turbo and 10R140 automatic transmission. I just got home pulling a 9000 lb 5th wheel from Tucson to Colorado Springs. The last day of the trip I noticed the truck seemed to run hotter than usual, getting up to 212 degrees on a long hill outside Santa Fe when I'm used to it being solidly center gauge (192 or so). Then, just as I get close to home, I noticed that shifting from 2nd to 3rd seemed to lug the engine and the temp would shoot up to 205-208 just running through the gears.
Any thoughts? Luckily I was within a mile of home, and I haven't moved it since I parked it. Maybe it'll be normal after it cools off??
P.S. - I-10 across southern AZ is the crappiest road I've ever seen - potholes for miles! But NM rocks...
Any thoughts? Luckily I was within a mile of home, and I haven't moved it since I parked it. Maybe it'll be normal after it cools off??
P.S. - I-10 across southern AZ is the crappiest road I've ever seen - potholes for miles! But NM rocks...
Thread Starter
|
4wd High
Joined: Aug 2025
Posts: 9
Likes: 1
From: Colorado Springs
Sorry, should've specified water temps rather than transmission temp. That was normal.
Thread Starter
|
4wd High
Joined: Aug 2025
Posts: 9
Likes: 1
From: Colorado Springs
True enough, June and 92 degrees on that Santa Fe hill - but it shouldn't go almost to the red on the gauge. I've convinced myself that it means that tranny is hard to turn and the engine is working too hard. Heading to the dealer and hoping I make it.
Laughing Gas
Joined: Nov 2010
Posts: 798
Likes: 263
The truck uses a PWM controlled coolant bypass valve. Until the fluid reaches 217* the valve restricts engine coolant flow through the transmission fluid heat exchanger.
Unless one/more of the following codes are present, it's operating normally.
P0218:00
P1783:00
P2681:00
P2682:00
P2683:00
P1783:00
You can prove it by unplugging the coolant bypass valve....trans temp will roughly follow water temp. It will also throw P2681 with no CEL but you will see there is no issue.
Unless one/more of the following codes are present, it's operating normally.
P0218:00
P1783:00
P2681:00
P2682:00
P2683:00
P1783:00
You can prove it by unplugging the coolant bypass valve....trans temp will roughly follow water temp. It will also throw P2681 with no CEL but you will see there is no issue.
Last edited by saratoga2011; Jun 8, 2026 at 09:15 AM.
Thread
Thread Starter
Forum
Replies
Last Post
89LX306
1999 - 2003 7.3L Power Stroke Diesel
29
Jul 12, 2011 04:03 PM
