I was sure the clutch was slipping?

[MagneticMeerkat]

I had (emphasise had, it's now probably been melted and made into a set of cheap saucepans) a Toyota Corolla with genuinely bad clutch slippage. It was evident in any gear, in that if accelerating the engine would rev up freely, then the clutch would sort of grab and catapult the car forwards. Kind of like automated power shifting, if anyone stills does that!! It was also interesting trying to pull away uphill - each time would elicit a silent prayer to the God of mechanics to just hold together one more time....

I digress, but it didn't go away ever. Not when cold, or driven gently, or fast, it just slipped all the time. What you describe could be potential contamination that has now burned off. Slave cylinder failure is possible, but I suppose it has to fail in the way that it isn't fully releasing pressure when you let go of the pedal, like the slave is somehow forcing the clutch plates apart a little. Normally if the hydraulic system fails you get the opposite effect, in that it's impossible to overcome the pressure plate spring action.

I would keep driving it and see what happens. If the clutch genuinely is dying you'll have many more miles before it does finally go.

[LeeThr]

TREMAiNE said:

podwin said:

Sometimes with the NOS kicking in, but I back off when I get a Manifold Failure warning.

You have to be careful with that, if you're not careful you could blow the welds on the intake

Then you'll have to get the Mad Scientist to replace the piston rings you fried

[podwin]

I have looked through the services history and it had a new clutch and clutch cylinder 14,000 miles ago, which is one of the reasons I bought it?

Also just spoke to a Nissan Dealer explaining the problem and he didn't mention the DMF, when I asked if it could be the cause he immediately ruled it out stating "Not on the Qashqai", odd.

Looks like I'll just have to forget about it, but it's bugging me.

[stevesingo]

How many miles now? Same previous owner.

If it has done 30k miles and is a one owner car on it's 2nd clutch...

[podwin]

I has done 122,000 miles!

I thought I'd take a chance on a high mileage but relatively young car, for a change (3.5 years old).

Clutch work was done at 108,000 miles and there is no other work prior to this in the extensive service history.

One previous (company) owner.

[The Wookie]

In that case if the clutch is very worn then it'll have less thermal capacity. Perhaps the friction coefficient is dropping off when it gets hot through (i.e. long journey heat soak from engine and gearbox) and coming back when it's cold.

[podwin]

But the new clutch has done less than 15,000 miles.

If the first one lasted for 100,000+ it shows it was driven well.

Maybe it has had a cheap one fitted.

[The Wookie]

Sorry only saw the 'clutch cylinder' part and 100k+ miles, not that it'd had a new clutch!

If it's only done 15k and you don't have a history of short clutch life then it can only really be a cheap clutch or faulty hydraulics! Perhaps the clutch master cylinder isn't returning properly and as things heat up and expand it's releasing some clamp load?