Yukon wont go over 3k rpm at w.o.t

[Joe Strahm]

I was driving my 2002 yukon 2wd with the 5.3 down a empty road and was trying to get some speed pulls. So I mashed the pedal and at wide open throttle i noticed that the motor doesn't rev over 3k rpms, but the weird thing is that the speed does build quite fast even though the motor wont go over 3k, so I turned the traction control off and I got the same result. Does anyone know if this is normal and is it because the gearing I may have?

 

[02_Tahoe]

I was driving my 2002 yukon 2wd with the 5.3 down a empty road and was trying to get some speed pulls. So I mashed the pedal and at wide open throttle i noticed that the motor doesn't rev over 3k rpms, but the weird thing is that the speed does build quite fast even though the motor wont go over 3k, so I turned the traction control off and I got the same result. Does anyone know if this is normal and is it because the gearing I may have?

Maybe the tachometer just doesn't read right. How fast does it accelerate?

 

[Rocket Man]

Did you shift it manually? As in, put it in first gear and then rev it?

 

[rockola1971]

Its normal for a 2wd. The engineers at GM know that anyone that would buy a 2wd simply cannot handle the almighty 5.3L. So the GM engineers built in the magic for us 4wd owners to surpass 3000rpm.

Nah...Im just messing with you. If your tach is good and accurate then something is wrong. Fuel filter is plugging up?

 

[Joe Strahm]

Sorry for the late response but I recorded a video/ after 40mph I floored it

 

[Rocket Man]

I don't see it downshifting. Did you try manually shifting it like I mentioned? Maybe your trans isn't shifting right.

 

[rockola1971]

I never saw any shifting. Looks to me the reason you can only go 3K or so is because your transmission isnt getting out of first or second gear.

Show a video of you starting from a dead stop and then accelerating to 55mph. (drive it normal, not like you stole it). We need to see if the tach dips during shifts.

Its a suv NOT a race car. You drive it like a race car and youll be replacing the tranny....often.

 

[Joe Strahm]

Ill have a video up shortly. The transmission shifts fine and smoothly and Ive had the yukon up to 90mph by partial throttle without any problems and the fluid is still pink, Does the 4l60e have a kickdown switch? I believe the transmission stays in a higher gear and doesnt drop a gear to accelerate faster.

 

[rockola1971]

Kickdown switch? No. The transmission will kickdown to the next lower gear based on throttle/load demand and the PCM controls this via the electric solenoids in your transmission valve body. You need 3 things to accelerate. Spark (on time), fuel/air(on time and in sufficient quantity) and Transmission to be in the correct gear and shift to the next correct gear. One or more of these is missing or incorrect value.

Spark timing is controlled by your PCM and generally by your timing chain (It jumps a tooth and your timing is wrong).

Air-Check filter, codes related to MAF, etc.

Fuel- Fuel Pump, Filter, Fuel lines, Regulator. (Easy check at the fuel rail with a gauge)

Transmission - Accelerate normally from a dead stop and watch tach or feel the RPM dropoff and that is a shift. Are you in 4th when you hit 45-50mph during normal acceleration?

 

[kushkyle]

I was driving my 2002 yukon 2wd with the 5.3 down a empty road and was trying to get some speed pulls. So I mashed the pedal and at wide open throttle i noticed that the motor doesn't rev over 3k rpms, but the weird thing is that the speed does build quite fast even though the motor wont go over 3k, so I turned the traction control off and I got the same result. Does anyone know if this is normal and is it because the gearing I may have?

did you ever find a solution? currently experiencing this with my 02 yukon slt 4wd