Ask an Expert..... » Automatic won't change gear under hard acceleration

#1 by rachel1977 , Tue Jan 12, 2016 9:58 pm

Hi everyone,
Got a 57 plate Warrior automatic. When you accelerate under normal conditions it changes gear no problem. If you put your foot down it gets to about 40mph and stops accelerating. It's like it's trying to change gear but can't, which is quite dangerous when you're trying to overtake! It doesn't stall or cut out, it just won't go any faster until you lift your foot off a bit,and then it changes up no problem.
I've tried googling it but every piece of advice recommends checking the oil level, which the mechanic has already done.
We're stumped, so any suggestions would be gratefully appreciated!

#2 by s1rally , Tue Jan 12, 2016 10:28 pm

Hi mine was doing this the other day, check the vacuum port on the inlet manifold to boost pressure sensor mine was choked with carbon. May need the manifold cleaned out.

#3 by Alan G , Tue Jan 12, 2016 10:32 pm

@skotl

Any idea Scott, didn't you have auto box issues.

#4 by 123hotchef , Wed Jan 13, 2016 6:47 am

what is the milage on the vechile has the AT fluid ever been changed

#5 by rachel1977 , Wed Jan 13, 2016 2:48 pm

Thanks guys. I'll get him to check those and let you know if it's still not fixed :-/

#6 by ronniecabers , Wed Jan 13, 2016 3:16 pm

Wasn't Skots a wiring loom issue?

#7 by Benson , Wed Jan 13, 2016 5:26 pm

I thought it was fuel filter

#8 by adriandiesel , Wed Jan 13, 2016 6:28 pm

there is a common problem with early new shape gearbox wiring looms but as for as i know it puts the box in limp mode.

#9 by FoxyChris , Wed Jan 13, 2016 8:47 pm

Doubt it's the wiring problem. That causes the limo mode problem and warning lights but don't think it would prevent a gear change. I'd say some kind of sensor fault or gear box fluid needing changing.

#10 by Major Malfunction , Wed Jan 13, 2016 8:49 pm

Is there a kick down button / sensor

#11 by rachel1977 , Thu Mar 24, 2016 6:57 pm

Now got additional problem: when it's in drive, it keeps slippibg oit of gear, like it's in neutral ut still says it's in drive. Goes fine in 2nd or reverse but not in drive. Had full AT fluid change and new filter but not fixed this or original issue. Are we going to need a new gear box?! Please help :-(

#12 by Nick , Fri Mar 25, 2016 7:50 am

Quote: rachel1977 wrote in post #11
Now got additional problem: when it's in drive, it keeps slippibg oit of gear, like it's in neutral ut still says it's in drive. Goes fine in 2nd or reverse but not in drive. Had full AT fluid change and new filter but not fixed this or original issue. Are we going to need a new gear box?! Please help :-(

If its jumping out of gear into neutral check the wiring loom to the gearbox,
This is normally caused by broken wires or wires rubbing on the bell housing or chassis.
Check each wire individually as they can break in the loom.

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Automatic won't change gear under hard acceleration

RE: Automatic won't change gear under hard acceleration

RE: Automatic won't change gear under hard acceleration

RE: Automatic won't change gear under hard acceleration

RE: Automatic won't change gear under hard acceleration

RE: Automatic won't change gear under hard acceleration

RE: Automatic won't change gear under hard acceleration

RE: Automatic won't change gear under hard acceleration

RE: Automatic won't change gear under hard acceleration

RE: Automatic won't change gear under hard acceleration

RE: Automatic won't change gear under hard acceleration

RE: Automatic won't change gear under hard acceleration