05 Yukon XL, 288k miles. Extremely slow acceleration from a stop, but as first gets the engine to higher RPM, it has plenty of get up and go, no issues with 2nd, 3rd, or 4th. I have it scheduled for an ATF change, hoping that might help. Hoping to get an idea of why it moves so slow off the line. Even putting my foot to the floor yields granny acceleration.
NEED HELP 1st Gear Sluggish from a stop
- Thread starter PSimm04
- Start date
Mooseman
Moderator
Don't discount a possible engine issue. Sometimes you think it's a tranny issue when the engine is having problems making power at lower RPM.
Another possibility is that it's starting in second gear. Did you check for any codes?
Another possibility is that it's starting in second gear. Did you check for any codes?
I am a lightfoot with a 2005 Yukon. Unless I move the accelerator pedal more rapidly my truck won't downshift worth a damn. I don't know of this is a result of torque management or what.
Edit: what gear ratio do you have? I was wondering how heavy you are on the pedal from a stop?
Edit: what gear ratio do you have? I was wondering how heavy you are on the pedal from a stop?
I'm usually fairly lightfooted myself, but occasionally i try and give it the beans from a stop if I'm trying to scoot out into traffic, and it just basically goes at its own pace until it gets to a higher RPM. I'm unsure of the gearing ratio. It has no problem downshifting once its in second or more. Plenty of power and pretty responsive. At least for a 288k mile 18 year old truck.
I also considered the engine as well, the only thing is that the thing makes ample power so long as you aren't trying to move it quickly from a stop. It's got a CEL right now but I suspect it's an O2 sensor. Trying to get it to the shop this week to see what all pops for codes.
I find when the transmission engages at a higher RPM, it is because it is low on oil or perhaps due for a change. I change my tranny oil and filter every 50k Kms (30K miles) and don't have a problem at 280K kms (170K miles). Good luck with the oil change - hopefully that is all it is. I also changed both O2 sensors this past summer. I got the occasional O2 code the replacing cured that and for some reason stopped a B2AA code which is an evap system error (which is strange).
That's what I was thinking myself. It's got a CEL right now that I'm pretty sure is related to the O2 sensors. The lowest grade of gas that runs out here in the Middle East is 91, so I'm unsure if that has affected the O2 sensors.
Chickenhawk
Member
- Dec 6, 2011
- 782
Does it have a cat converter on it? If so, it might also be plugged. This is most noticeable at highway speeds where it struggles when speeding up or climbing hills.
It's got a cat converter but it has no problem getting up hills or accelerating hard on the highway. That's what really confuses me. The problem only exists when trying to accelerate hard from a stop.
Mooseman
Moderator
So have you changed the filter and fluid? There have been instances of poor performance and corrected after they were changed.
It's in the shop as we speak for full flush and filter change. More to follow when I get it back tomorrow.