I have no idea if this is usual or what, but when I accelerate hard, sometimes, between 4000 and abt 4800 revs the engine races - it almost sounds like the clutch is slipping, as the revs rise very suddenly then level out and increase linearly after that. Now, this mainly happens when at part throttle at abt 3500 revs and then I floor it, but not when I pull away or from no throttle.

Can somebody explain this or is there a problem ?

 

Sounds like worn clutch (already?) or too much torque for clutch (has it been mod'd?). How much does it speed up to, and does it drop back down slowly(ish) to what it should be and then keep climbing as if accelerating normally again? Someone else had a similar problem recently, cant remeber who or what thread, but general advise was if it is under warranty then get it checked out under the warranty. Dont believe them if they say its supposed too either, but by sounds of it you dont seem like youd belive them anyway. Will be interesting to hear what the fault is.

 

Mx5's have a problem where hydraulics can leak onto the friction plate causing clutch slip.....just a thought.

 

Thanks FreeT - I'm probably not explaining myself really - revs rise very very quickly between 4000 and 4800/5000 and then the acceleration keeps on but at a slower rate. It doesnt happen at any other revs.
Clutch was my first thought but that would surely happen when changing gear and when in the process of engaging the clutch - not when fully in gear ?

 

I can only think of the clutch and its slipping at that point because its reaching peak torque at about those revs, and maybe even a slight leak (as sieze says or even oil) inside may cause it to slip only at theat critical point. Doesnt help you mutch - sorry cant be more help. Does it do it in every gear at this point or just the higher ones?