Revs surges then drops on upshift

[Latifah]

Hello. When i upshifts (especially from 3rd gear onwards), the revs surges before then dropping down (usually by about 500rpm) to a lesser value and then slowly increasing back up.
For example i go from 3rd to 4th the revs surges to 3000rpm then a couple of second latter drops to 2500rpm and then again starts to increase to 3000rpm. Usually if i floor it more the drop is more noticeable (maybe as much as 1000rpm).
Can someone guide me as to what might be the problem? Is it something with the throttle body, transmission such as slippage (my car is a manual) or something else?

 

[Alin2225]

Clutch?

Sent from my W_C800 using Micra Sports Club mobile app

 

[John_D]

Sounds like a slipping clutch to me, either worn out or oil contaminated, either way only fixed by complete replacement (3 pieces, pressure plate, friction plate and clutch release bearing)

 

[Latifah]

Update: Had the Transmission service today, the clutch material was completely shot, so i was basically going metal on metal, and was slipping causing the drop in rpms intermittently.
They replaced the friction and pressure plate, the clutch release bearing was fine and didnt need changing. The front brake rotors were resurfaced, the brake fluid and gear oil changed and, the front bearing on one side and the rear bearing on another side were crushed and had to be changed as well. The rear brake cylinders on each side were leaking and thus needed replacing as well).

I have just driven the car back home and had no slippage; so i guess thats another problem solved. However, i noticed my clutch pedal feels super soft, it shifts alright and depresses and rises fine but its just soft almost as if no pressure in it, my previous one was quite a workout to depress. Is this how it is supposed to be? or is it another problem that needs to be fixed?

 

[John_D]

Big mistake not replacing the clutch release bearing at the same time as the friction and pressure plates. It's the cheapest part, only a few pounds and should be changed automatically as a matter of course when replacing a clutch. If it starts getting noisy in the future (quite possible) you will have a massive labour cost to replace it! Also, when changing the clutch on these it is prudent to change the crankshaft oil seal, behind the flywheel, again, just a very few pounds for the part and just an extra half hour or so labour to change it while the gearbox is out. Again if it starts leaking in the future you will have a massive labour charge to replace a part that costs about a fiver!

 

[Latifah]

Big mistake not replacing the clutch release bearing...!

Bummer. I asked about they said its fine and there was no need for change since it was still in good shape. Same for the seals they said unless its suppurating around the edges to leave them be. Guess they figured i would thus have to come back qgain in future for thr rest.

 

[Alin2225]

I wonder how they managed to give the bearing diagnostic that it is fine since i ve never heard about a testing procedure. For the mechanic ones yes maybe you can do a visual inspection....but for this one.....strange!

Sent from my W_C800 using Micra Sports Club mobile app