Howdy, all

I've been having issues with my 7.3l powerstroke excursion. When I first start the truck, the transmission seems to delay before shifting into the selected gear.
For example, I'll select "Drive", and when I accelerate, it's as if I am in neutral. Usually, if I wait 10-30 seconds, it starts to respond. (you can see the subtle change in RPM as it engages. If you accelerate before the gears "catch", sometimes as you increase the RPMs, the transmission will catch and the truck will start to move. (I try no to do this, as I worry about adding strain to the transmission if gears arent properly engaged).

This only happens when you first start the vehicle. After I get moving, it tends to shift fine. I can later shift from drive, to park, to reverse, or back to drive without issue, so long as I've been driving around for a bit... Like everything needs to warm up, and its fine...?

It might be coincidental, but as it got colder this year, the problems have worsened (its worse when its colder. I'm in SE Texas, so temps have made it down to the 20's on a couple occasions, but nothing extreme. 30s-50s average lows)

I've done a little reading, and it seems like the solenoid may be wearing down. Does this sound consistent to the experts here? or am I off in left field chasing butterflies?

Thanks

J

 

I am sure you have already checked this, but I am just throwing it out there just in case. If the trans is just a little low on fluid, it can cause similar symptoms.

 

Which solenoid do you mean? There are five of them. I think you are referring to the EPC (Electronic Pressure Control) solenoid. I don't think that's the issue.

Tomorrow morning try this test. It may help me narrow down what your problem is. Before shifting out of park let the engine idle for at least 30 seconds. Then shift it. Does it now engage in a normal time, or is there still a delay?

 

Thanks for the responses. Tranmission fluid is at normal level.


I'll check this tomorrow morning, though the temperature outside is supposed to be in the 70's (I only mention that because it seems like it happens more when its colder). I'll report back tomorrow.

 

Weather was warmer today. ~70*.

Started the truck, selected Drive. Shifted to drive after sitting for ~30sec. The transmission switched into drive with slight delay (not as delayed as other mornings... probably ~3-5+seconds delay, which is more than when my truck ran well). I was able to accelerate gently and move the truck forward with no difficulty. However, when reversing back into my spot, the movement was very rough. It almost felt similar to when I was driving a vehicle with a manual transmission, and had let the clutch out too fast or not given enough gas. A little bit of sputtering, seemed like it wanted to choke and die. I quickly stopped, pressing the brake, and everything normalized. As I tried again to reverse, everything worked fine.

My wife later told me that a few minutes after I tested it, she went to run an errand in the same vehicle. She placed it in drive, and went to accelerate, but nothing happened. (The best i could tell from her account, is that it just acted as it was in neutral - revved up RPMs, no movement). She let the RPMs die down, the gently tried to accelerate again. As she gently accelerated, the truck began to move, but it was very sluggish at first.

Subsequent times during the day, this is less of an issue. Usually (USUALLY) only first thing in the morning.

 

When you check the trans fluid level, is the engine idling in park? Is the trans warmed up?

If you answer yes to both of these, we need to dig further. The next step would be to put a 0-350PSI gauge in the test port on the side of the trans. I need the pressure readings (warmed up) in each position, PRND21 with the engine idling. I also need it with the go pedal on the floor in R, D, 2, and 1. DO NOT HOLD THE GO PEDAL ON THE FLOOR FOR MORE THAN 5 SECONDS AT A TIME. ALWAYS ALLOW A 30 SECOND IDLE PERIOD AFTER EACH 5 SECONDS WITH THE TRANS IN P OR N.