NISSAN SUNNY FB15 High rpm

[Janitha Jayasinghe]

I recently bought a NISSAN SUNNY FB15 2003 made one. It has relatively high rpms while driving compared to other cars of same model.

At 75km/h > 2500 rpm

80km/h> 3000 rpm

100km/h> 3700 rpm.

Up to now I have done a tune up (Cleaned throttle body, injectors. Plugs and coils are good).

Changed gear oil as the mileage reached.

When scanned there are no any DTCs.

Can someone help me to identify the problem?

Pls see the attached images for your reference.

[iRage]

How is your transmission ? Does it feel like it is slipping ? From a stand-still do you have to accelerate a bit hard for it to start moving ?

What is the idle RPM like ?

[Janitha Jayasinghe]

Hi iRage,

Thank you for your reply.

It is a four forwarding automatic transmission model. It doesn't feel slipping and it starts moving smoothly. Idle RPM is 700 without A/C.

I'm planning to check if the transmission shifts to overdrive or not as I don't feel the shift from 3rd gear to 4th gear. I will update this thread accordingly. Meanwhile I would love to hear the suggestions.

[Twin Turbo]

Switch on O/D

 

[iRage]

16 hours ago, Janitha Jayasinghe said:

Hi iRage,

Thank you for your reply.

It is a four forwarding automatic transmission model. It doesn't feel slipping and it starts moving smoothly. Idle RPM is 700 without A/C.

I'm planning to check if the transmission shifts to overdrive or not as I don't feel the shift from 3rd gear to 4th gear. I will update this thread accordingly. Meanwhile I would love to hear the suggestions.

Hmmm....I would say that seems pretty normal...like Twin Turbo mentioned...does the OD turn on and off properly ? Becareful when you try to shift from 3rd to 4th...you might have to end up doing quite high speeds

[Janitha Jayasinghe]

17 hours ago, Twin Turbo said:

Switch on O/D

 

 

16 hours ago, iRage said:

Hmmm....I would say that seems pretty normal...like Twin Turbo mentioned...does the OD turn on and off properly ? Becareful when you try to shift from 3rd to 4th...you might have to end up doing quite high speeds

O/D is switched on whole time.

at 100km/h I have tried switching off O/D after taking foot off the accelerator paddle. When I take foot off the paddle, engine rpm goes nearly 1200 rpm and at same time when switch off O/D, rpm goes to 2100 rpm. Therefore I think gear shifts from 3rd to 4th. But need to verify this. TCM does not connect to scanner and need to check further.

[Thilina007]

Might be helpful to get some idea ( Car is manual tho' FB 15 2003)

At 5th Gear with AC / head light on;

 

 

Edited February 12, 2022 by Thilina007

[Janitha Jayasinghe]

On 2/12/2022 at 12:01 PM, Thilina007 said:

Might be helpful to get some idea ( Car is manual tho' FB 15 2003)

At 5th Gear with AC / head light on;

 

 

Thank you. I have seen same on automatic transmission car. At 100km/h rpm nearly 2200. There is no issue in TCM as well. Still no idea though. I will update the progress accordingly. 

[Janitha Jayasinghe]

Up to now I have done the following.

1. Done a tune up (Cleaned throttle body, injectors. Plugs and coils are good).

2. Changed gear oil as the mileage reached.

3. Scanned the TCM and there are no any DTCs. Also I have switched 4 TCMs and checked and still the same. So the issue isn't with the TCM.

4. Checked the valve body. All solenoids are ok and lines are clean as well.

Now pending works are to check the the torque converter and the gearbox. But I believe as 1st,2nd and 3rd gears are shifting around 2000rpm, the issue isn't in torque converter and the 4th gear must be slipping.

[Janitha Jayasinghe]

I have decided to repair the automatic transmission and I will soon update this result.