RPM JUMPING OUT OF CONTROL!!!!

[thebum23]

Hi, i own a 2000 Maxima and till now everything seemed to be fine! I recently found that after driving the car for a while and hitting open roads of speeds of 40mph and up suddenly out of nowhere i will try to accelerate but the rpms would just jump to 5 and up but the speedometer would just sit at the speed it was lost on...Its kind of as if i were in neutral! I have taken it to the mechanic but so far they do not come across this problem when taking the car for a test drive. I know the problem is there because it happend to me already 3 times and its pretty scary actually to be in the middle of a highway and all of a sudden not be able to accelerate and just have the rpm's shooting up! Anyone else experience this with their maxima and know what it might be???

[DevonD]

hmm. I think its called the kick down sensor? or knock down? Kick down sounds right to me. It just tells the transmission what gear to shift into and figures this out by looking at your speed, engine rpm's and how far you have shoved the gas pedal into the floor deciding how fast you want to speed up.

Is it when your just speeding up or is it out of nowhere it pops out of gear?

[thebum23]

Hey, thanks for the reply! Yes, it only happens when im cruising and then i accelarate and thats when the rpms shoot up but the speedometer wont move! So is this kick down sensor in the transmission?

[DevonD]

Yeah the speedo wont move because the car is going into neutral. it misses the gear it wants to hit the to save the transmission from damage its not going to slam it into gear! Im not sure where the sensor is on these cars.

How mechanicaly inclined are you? YOur best bet might just be taking it to a shop and having them inspect it and or replace it.

[bpomps]

I am having this exact issue -

mechanics cannot figure it out.

Did you fix your problem? can you please let me know what you did to fix ?

[thebum23]

So Devon i spoke to my mechanic and tried to mention to him what you told me but he said that what your talking about is something that happens with manual cars...Mines an automatic! This problem is driving me up the wall! I have a full warranty on my car but the mechanic wont take out the transmission because they cant really see a problem. And if an inspector from the warranty company comes out to look at the car, he will see that it all checks out and they wont authorize the transaction!!! this is such a nightmare...

[maxhopper]

When you step on the pedal, is it just an slight increase in pressure; or do you stomp the pedal to the floor?

[MinisterofDOOM]

So Devon i spoke to my mechanic and tried to mention to him what you told me but he said that what your talking about is something that happens with manual cars...Mines an automatic!

What Devon is describing is definitely unique to automatics.Automatics use the amount of throttle to help decide what gear to be in and when to shift. Part of that is the kick-down switch, which detects that you have the throttle FLOORED all the way. When it sees that, it automatically drops a gear (unless it would mean over-revving the engine). The kick-down switch only comes into play when you floor it completely though.

[bostickg]

IM HAVING THE SAME PROBLEM WITH MY 2000 GLE. IT ONLY HAPPENS AFTER IVE BEEN DRIVING FOR A WHILE AND THEN WHEN I GO TO ACCELERATE, THE RPMS SHOOT UP AND THE CAR SEEMS LIKE ITS IN NUETRAL. SOME TIMES WHEN ITS ACTING UP I WOULD GAS IT TO THE FLOOR AND IT WOULD TRY TO CATCH IN GEAR. WHEN I COME TO A COMPLETE STOP AND START DRIVING AGAIN IT WILL ACT RIGHT FOR A FEW.