Auto bogging down after 4th gear

[DannyBoy]

Hi all,

As I drive along flat ground shifts from 1st, 2nd, 3rd once it shifts into 4th and also 5th gear it bogs down and is hesitant when pushing the peddle in (no jerking motion)

Once its up into 5th gear if I manual shift it into 4th it feels and drives smooth.

Going up hill is the same it wont down shift, example - hitting the hill in 5th gear it continues in 5th and the RPM's will go down to roughly 1100RPM, If i plant my foot itll kickdown to 3rd, I have tried gradually pushing the peddle in to see where and when itll shift itself.

from doing some google search I cant quite figure out what may cause this but im assuming something like the Trottle Position Switch or something to do with gearbox vacuum?

Any help appriciated cheers!

 

[Old.Tony]

My first reaction is blocked/impeded valving in the gearbox.

You could grab a bluetooth OBD adapter, an Android smartphone and Ian Hawkins' Torque app off the Play store. Armed with this, you can get data from the TPS and engine load sensors. They will tell you if that part of the system is working properly before you spend any coin taking the car to an auto box specialist.

 

[DannyBoy]

My first reaction is blocked/impeded valving in the gearbox.

You could grab a bluetooth OBD adapter, an Android smartphone and Ian Hawkins' Torque app off the Play store. Armed with this, you can get data from the TPS and engine load sensors. They will tell you if that part of the system is working properly before you spend any coin taking the car to an auto box specialist.

I checked out Torque App and recorded an engine load / trottle position graph:

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Is it easy to pull the transmission valve module out and clean / inspect it?

 

[Old.Tony]

That's pretty clearly pointing away from a TPS fault.

Personally I'd leave the internals of the box to an auto specialist, although there are some here that have taken theirs apart to clean it up themselves, hopefully one will come past this thread!

 

[DannyBoy]

Ive got her bookef in for Thursday to br checkef out hope its a cheap fix. Thanks heaps Tony!

 

[DannyBoy]

Auto transmission place said it is the torque converter locking up from 3rd to 5th gear. doesnt know the exact cause as he will need a day or two to have a good look which he cant do right now but can next week.

Good thing is they dont charge for diagnosing the problem, he said if he gets a auto electrician in to the test the system thats all he will charge me for.

from one of my others posts: http://www.navara.asia/showthread.php?t=30301
I would say the extra load from being in 4H is causing the extra vibration due to lock up of TC.

Done a quick google search on TC lock up and read about changing fluid and filter also tigjtening valve body up, I know nissan have said that the ATF is in for life but would that only apply to only on road driving and not off road / towing..thoughts?

 

[DannyBoy]

Drain a littke into a small clear container. its a browny color and smells like a burn type of smell doesnt smell like the Nulon ATF I have on me.

 

[Old.Tony]

I've asked the question before - what do they mean (in terms of km) when they say "lifetime" when it comes to the ATF? You would expect it to be reduced when towing, or dragging off Ford FPVs at Summernats (you wouldn't dare try dragging off a Lada).

 

[DannyBoy]

I've asked the question before - what do they mean (in terms of km) when they say "lifetime" when it comes to the ATF? You would expect it to be reduced when towing, or dragging off Ford FPVs at Summernats (you wouldn't dare try dragging off a Lada).

Exactly! I am upto 75k on the clock unsure if the fluid was changed at the 40k service and unsure where and what the car has been upto from 0k to 54k.

Going to look into it and possibly try changing out the fluid to see if will fix the problem depwnding on info I get from searching

 

[DannyBoy]

I got it back today and they have said that the transmission computer is sending the wrong signal and that the pressure is lower than it should be.

Was told it is a $3600 fix (New Valve body / module) also possibly another $2000 for reconditioning the gearbkx as the seals etc may be damaged.

I still have Nissan 3 year warranty which I have booked it in to get them to have a look bit worried that they wont cover it due to hearing others being knocked back with warranty claims

 

[Ben 75]

Hi , did you get outcome from nissan it seams I have a similar problem in my 2012 st d 40 auto and it's very annoying