Nissan Micra NCVT issues

Hi guys,

I've recently bought a `99 Nissan Micra 1.3 NCVT for my wife. She is a newbie driver and wanted to go the easy way with the automatic transmissions. The car was flawless and she was very happy until it recently started to give some defects.

Initially it just started to somehow misfire when you put it on heavy load like climbing very narrow road while having your AC on. At first I had a doubt about eventual problems with the gearbox, but they have tested it in the local repair center (not official one) and they've stated that since it does not over rev while driving or get stuck during gear change it is perfectly fine. After a bit more empirical research it actually turned out that the ignition module was failing. I've replaced it and now it does not have any misfiring from the engine and works like a charm. As they say in Wheeler Dealers: RESULT!

After a few days of joyous ride my wife complained that when she drives very slow and put her feet off the throttle pedal the car begin to "wobble", as she said. I have tested it and it is behaving like it has a curved brake disk (oh boy ... it is hard to explain this in English). It is just like pressing the brake very gently and then releasing it in a very short manner and it goes like this over and over again. The car just pulls for a moment and then it lets idle and then pulls back and idling again very gently.

After reading few days random posts and documentation over the internet I am embracing the idea that this has to do something with either the primary or the secondary pulley speed sensors, but I am not quite sure. I tend to think that this is the appropriate reason for the problem just because I have no other issues with the magnetic clutch mechanism (like the stuck gear lever symptom mentioned above). Unfortunately I only know about these sensors just from a schematic that I found over the internet and few posts mentioning them. I am not able to get part numbers etc. I guess that such 'sensors' cannot be very expensive and it will be worthy changing them just for the experiment.

Can anyone help me out or at least guide me in some direction with this issue?
 
OP
OP
onassin
Thanks for the idea Andy, I will do it! I have read somewhere about them, but just didn't paid too much attention.
Unfortunately I cannot do it myself - I certainly don't have the appropriate place and might not have the sufficient skills for that so this will be done in service center in the coming few days.
Can you please give me a hint where I can eventually find the spare parts? A website with international shipping maybe?

P.S. I've also read the topic, that you've mentioned, but the information there is too patchy and will have to go through it again.
 
Last edited:
Hi mate I will look for the parts numbers for the electromagnetic brushes and brush holder, I used a genuine Nissan replacement part cost around £200 because this is such an important part in the automatic transmission I did not want to chance a clone part but they are available and cheaper! Also the genuine Nissan part will last the rest of the car's life and I did not want to change the part again!
Cheers
Andy B-)
 
Hi here are some pics of the electromagnetic brush holder including the part box with the Nissan part number on it! :)

This is the location of the electromagnetic brush holder:
micra-k11-cvt-transmission-brush-holder-location.jpg

This is the aperture with the brush holder removed note the armature that the brushes make contact with and the rub marks:
PA311718.JPG

The new electromagnetic brush holder!
P8251605.JPG

The Nissan electromagnetic part number: 30051-41B00 on the packaging:
P8251603.JPG

The new electromagnetic brush holder fitted, warning tighten the 2 brush holder bolts to the correct torque setting of 7Nm or lbf ft 5:
PA311722.JPG


Full details on how to remove and fit a new electromagnetic brush holder is in the Nissan Micra 1993 to 2002 (K to 52 registration) Haynes Service and Repair Manual.
Chapter 7 Part B: Automatic Transmission page 3

Hope the above details and pics help please feel free to ask if you need more information or help! :)

Cheers
Andy :D
 
OP
OP
onassin
Hi all,
Thanks for the pictures and the part numbers.

Meanwhile I would like to add new "symptom" to the previous post explaining the problem.
I've noticed that when traveling with relatively high speed (70 km/h) while hitting the break a bit hard (not to slide wheels, but just hard enough to stop fast) and when reaching about 20-25 km/h while slowing down there is something like a slight hit from the engine bay and the car over rev for a moment. It is not happening all the time. If the car decides to do it today, it will most probably do it the whole day long. Other days might not do it at all. It does not seem to be the ABS, because it will have nothing to do with the engine revs (at least I think so).
This car is so astonishingly exotic and extravagant. I think that if it wasn't this interesting and with such a clever engineering solutions, I would have sold it by now.
 
Last edited:
OP
OP
onassin
I just want to make another update. Finally I was able to distinct the occasions of when the car is doing the problem, described above. and when not.
Interesting fact is that it does it only when it rains. We've couple of very "wet" months where I live and I wasn't able to make this observation earlier.
So according to my "technical" knowledge there are two options.
The fist one is to have some electrical sensor issue with bad contact or something like this.
And the other option should be something related to the changed ignition module.
Maybe I have to make more detailed calibration with stroboscope.
 
Hi guys,

I've recently bought a `99 Nissan Micra 1.3 NCVT for my wife. She is a newbie driver and wanted to go the easy way with the automatic transmissions. The car was flawless and she was very happy until it recently started to give some defects.

Initially it just started to somehow misfire when you put it on heavy load like climbing very narrow road while having your AC on. At first I had a doubt about eventual problems with the gearbox, but they have tested it in the local repair center (not official one) and they've stated that since it does not over rev while driving or get stuck during gear change it is perfectly fine. After a bit more empirical research it actually turned out that the ignition module was failing. I've replaced it and now it does not have any misfiring from the engine and works like a charm. As they say in Wheeler Dealers: RESULT!

After a few days of joyous ride my wife complained that when she drives very slow and put her feet off the throttle pedal the car begin to "wobble", as she said. I have tested it and it is behaving like it has a curved brake disk (oh boy ... it is hard to explain this in English). It is just like pressing the brake very gently and then releasing it in a very short manner and it goes like this over and over again. The car just pulls for a moment and then it lets idle and then pulls back and idling again very gently.

Depois de ler alguns dias publicações aleatórias e documentação pela internet, estou adotando a ideia de que isso tem que fazer alguma coisa com os sensores primários ou secundários da velocidade da polia, mas não tenho muita certeza. Eu tenho a tendência de pensar que esta é a razão apropriada para o problema só porque eu não tenho outros problemas com o mecanismo da embreagem magnética (como o sintoma da alavanca de câmbio preso mencionado acima). Infelizmente eu só sei sobre esses sensores apenas a partir de um esquema que eu encontrei na internet e alguns posts mencionando-os. Eu não sou capaz de obter números de peças, etc. Eu acho que tais 'sensores' não podem ser muito caros e será digno de alterá-los apenas para o experimento.

Alguém pode me ajudar ou pelo menos me orientar em alguma direção com essa questão? [/ QUOTE]
 
Top