Automatic shifting issues with 2001 7.3L F250

[cannesdo]

Just today it starting staying in (I think) 3rd and reving up rather than moving onto fourth. (Didn't rev like it was in neutral. It was still accelerating but the RPMS were wound way up) If I accelerated really carefully I could get it to shift all the way up without "sticking" but if I was hitting the gas hard at all it (or even normally) it would stay in 3rd and rev. If I take my foot of the gas it will usually shift up to fourth, but not always.

It started when I was accelerating pretty quickly which I don't normally do -- not crazy fast, just quite a bit faster than usual. Last week I towed my 36' foot fifth-wheel for two days but I've been driving it for five days now without any issues. Drove down the mtn today from Woodland Park, CO (just the truck) to Colorado Springs (from a cool place to hot place if that's relevant) and it started when I was down there. Also dropped 2000 ft. No idea what could affect this so I'm throwing everything out there.

I was really concerned about it climbing up to Woodland Park last week as it was a hot day. I waited down below and cooled it off before starting the climb. Engine temp maxed out at 128 and transmission temp was about 112. I usually don't let it go any higher than that but had gone that high many times before so I thought it was probably ok for the short climb (15 min. Worst of it was only about 7 min. Took the climb like a champ.

Had the truck since '07, put 40K miles on it since then, 130K total... not much towing. I stay in each place for quite a while.

Thanks for any input.

The truck is chipped (Edge Evolution) No warning lights came on today. Should I disconnect the chip and see if that resolves it? I checked all the fluids before leaving. I'll check them again in the morning.

[carringb]

cannesdo wrote:


Ok, found out that more specifically it means the turbo boost pressure is low.

Low boost causes you to require more throttle to do the same work. The transmission however relies on the throttle position sensor for shift point, and doesn't really know how much power the engine is making (or not making).

Adress the boost issue, and shifting issue will probably go away.

Are you running a K&N filter? Pretty common for them to allow abrasives into the turbo which eats up the impeller. And it could also be a restriction pre-turbo, or a leak after the turbo. Small leaks make lots of noise, but large leaks sometimes can't be heard over the other engine noise (usually you can hear more turbo whine though).

[cannesdo]

From the Edge website: "Px2xx measurement of air and fuel"

My air filter needs cleaning -- could that be it?

Ok, found out that more specifically it means the turbo boost pressure is low.

[cannesdo]

I ran the code diagnostic on the Edge chip and it came up with "Code 1 of 1: P1247 is unknown."

[cummins2014]

cannesdo wrote:
Just today it starting staying in (I think) 3rd and reving up rather than moving onto fourth. (Didn't rev like it was in neutral. It was still accelerating but the RPMS were wound way up) If I accelerated really carefully I could get it to shift all the way up without "sticking" but if I was hitting the gas hard at all it (or even normally) it would stay in 3rd and rev. If I take my foot of the gas it will usually shift up to fourth, but not always.

It started when I was accelerating pretty quickly which I don't normally do -- not crazy fast, just quite a bit faster than usual. Last week I towed my 36' foot fifth-wheel for two days but I've been driving it for five days now without any issues. Drove down the mtn today from Woodland Park, CO (just the truck) to Colorado Springs (from a cool place to hot place if that's relevant) and it started when I was down there. Also dropped 2000 ft. No idea what could affect this so I'm throwing everything out there.

I was really concerned about it climbing up to Woodland Park last week as it was a hot day. I waited down below and cooled it off before starting the climb. Engine temp maxed out at 128 and transmission temp was about 112. I usually don't let it go any higher than that but had gone that high many times before so I thought it was probably ok for the short climb (15 min. Worst of it was only about 7 min. Took the climb like a champ.

Had the truck since '07, put 40K miles on it since then, 130K total... not much towing. I stay in each place for quite a while.

Thanks for any input.

The truck is chipped (Edge Evolution) No warning lights came on today. Should I disconnect the chip and see if that resolves it? I checked all the fluids before leaving. I'll check them again in the morning.

It sounds like it could be the shift solenoid or sticking shift valve, common occurrence on a 4R100. Mine would be intermittent shifting out of second to third which is the most common shift problem. Never knew when mine was going to do it. Did it two or three times , then for about the last six months that I had it ,it had no problems. It did it after being warmed up, then shut off for a brief time ,and then driven again still warm it would not shift out of second.

[cannesdo]

Oh sorry...I wrote that wrong. Engine was 228 and tranny was 212.

[pauldub]

I think you must be reading your engine and tranny temps in centigrade. That would make a lot more sense but wouldn't be great because 128 would be 262 degrees F and the tranny temp would be 233 F. Seems like the engine is a bit on the hot side and the tranny is about as expected.

I'd disconnect the Edge before doing anything. I helped a friend of mine diagnose a drivability problem on his Dodge and the problem completely went away when the Edge was disconnected. He had to send the Edge back to the manufacturer for repair.

[cpaulsen]

cannesdo wrote:
Just today it starting staying in (I think) 3rd and reving up rather than moving onto fourth. (Didn't rev like it was in neutral. It was still accelerating but the RPMS were wound way up) If I accelerated really carefully I could get it to shift all the way up without "sticking" but if I was hitting the gas hard at all it (or even normally) it would stay in 3rd and rev. If I take my foot of the gas it will usually shift up to fourth, but not always.

It started when I was accelerating pretty quickly which I don't normally do -- not crazy fast, just quite a bit faster than usual. Last week I towed my 36' foot fifth-wheel for two days but I've been driving it for five days now without any issues. Drove down the mtn today from Woodland Park, CO (just the truck) to Colorado Springs (from a cool place to hot place if that's relevant) and it started when I was down there. Also dropped 2000 ft. No idea what could affect this so I'm throwing everything out there.

I do not understand the temps you gave.....128 for the engine and 112 for the tranny. Normally should be...around 195 for the motor and 160-180 or so for the trans.

I was really concerned about it climbing up to Woodland Park last week as it was a hot day. I waited down below and cooled it off before starting the climb. Engine temp maxed out at 128 and transmission temp was about 112. I usually don't let it go any higher than that but had gone that high many times before so I thought it was probably ok for the short climb (15 min. Worst of it was only about 7 min. Took the climb like a champ.

Had the truck since '07, put 40K miles on it since then, 130K total... not much towing. I stay in each place for quite a while.

Thanks for any input.

The truck is chipped (Edge Evolution) No warning lights came on today. Should I disconnect the chip and see if that resolves it? I checked all the fluids before leaving. I'll check them again in the morning.

[cannesdo]

It's not normal. If it's not third it's second. It's a low gear -- about 25 mps. When it's time to go up to the next gear it stays in the lower gear and winds up. When I get to 35 or so it stays in that gear and sound like it's going to snap. Imagine going 20 in first gear. It sounds like that.

[carringb]

Sounds like normal operation to me. It should not go into OVerdirve under high load unless you reach max RPM for 3rd.