Help!! Transmission issue?

[Kali2024]

Hi all I've got some funny things going on (04 mountaineer AWD V8):
• the accelerator pedal seems stiff, hard to depress
• sometimes really have to push when in the last two gears, and doesn't do anything, no go, rpms stay the same-don't jump up
• immediately after shifting up, there's a "hiss" suction like, or almost like air escaping from hose. Does not do this when down shifting
• shifting seems to have changed, delayed between shifts especially into last gear
• these symptoms see to be getting worse as it gets colder

Any thoughts?

 

[ragajungle]

Not sure about the hissing but is sounds like the throttle cable and or kick down linkage is binding. how do the cables look? Bent?

 

[swetrid]

04 doesn't have any cables, drive by wire throttle body. Could be the pedal assy is binding.

 

[ragajungle]

^^ Did not know that ^^

 

[imp]

^^ Did not know that ^^

The throttle plate is now rotated by an electric motor, driven by the computer (PCM) in response to input from the "gas pedal". This system allowed (eventually) the builders to eliminate the Idle Speed Control (ISC/IAC), as the drive motor now adjusts idle speed as needed, independent of the gas pedal.

An ulterior motive was included in going to this system of throttle control; if you care to know, please ask. Am attempting to limit my running on at the mouth here lately! imp

 

[D Hook]

I'm asking. Always interested in ulterior motives; automotive and otherwise.

 

[swetrid]

They do it for fuel economy!

 

[imp]

I'm asking. Always interested in ulterior motives; automotive and otherwise.

Here's the way I heard it: Taking away direct engine output control from the driver allows the computer (PCM), under certain conditions which might be expected to cause engine or driveline damage, to not HONOR a gas pedal request for, say, full throttle. As an example, if the engine were running hot, and getting hotter, the PCM can lower max. power available regardless of gas pedal position. Similarly, low oil pressure, high propensity for spark "knock", or lowered eng. response to ignition advance/retard, can cause reduced power available. Obviously, I call this "ulterior", but the makers' aim is certainly to prevent mechanical damage while the damn thing is still under warranty! Sure as hell, if reduced power/gas pedal input occurs, there will be a "Check Eng." thrown.

I question the possible danger programmed into this scheme: Suppose a guy is driving a 2-lane, narrow road with no shoulders, like we negotiate every day in rural Missouri, pulls out to pass, "floorboards" his gas pedal, experience with the vehicle telling him he has ample power to safely pass, and just then PCM decides "Uh, uh", only 50% available, eng. too hot? Would this not pose a real danger? imp

 

[D Hook]

Shucks. I was thinking of something much more nefarious like grassy knoll-second shooter sort of thing.

But reduced control unexpecedly; that's good too.

 

[matt0248]

Another thing the drive by wire gets rid of is the cruise control servo and cables.

 

[imp]

Another thing the drive by wire gets rid of is the cruise control servo and cables.

Good point! How desireable that is could also be debated. The old system had a cable which worked in parallel with the throttle cable from the gas pedal.

As the mechanical methods of doing everything gave way to electronic controls, it "mystified" the common everyday guy who was able to figger things out before, on his own. imp