I don't understand my car...

[Mellow7]

...or to be precise, I don't understand my clutch!

2002 Roadsport 1800 SS bought from Millwood in 2008 with just 1600 miles on the clock. The bite point has always been high/sensitive to the touch and often slips in 3rd from the Severn Bridge Toll Grand Prix, but I thought it was down to my bad driving. Numerous mods over the years, including a new clutch release bearing 2 years ago as the original was very noisy and getting stiffer and stiffer. I asked Millwood to change the clutch at the time (circa 8k miles) and they said there was nothing wrong with it/plenty of life left.

So I'm now running the car with over 200 bhp with just short of 12k miles. However, when Emerald were mapping the car last summer the clutch kept slipping right on max power (I was fed up having taken 7 hours to get there faced with all the wasted time and money, pluus a new clutch) until all of a sudden it stopped slipping and they were able to fully map the car. There were no signs of the clutch playing up on the long drive home.

But ever since, sometimes it slips, sometimes it doesn't (at all). I am waiting for a slot for Millwood to replace the clutch but only yesterday during a really good blat even when I abused it, the clutch simply would not slip. What I have noticed is there appears to be a cycle - from cold, loads of torque (obviously as the air feed is cold) but no clutch slip; just warmed up - engine goes a bit flat and this is often when the clutch slips if it is going to; engine really hot/full on blat, engine takes on a new life in the upper rev range BUT the clutch stops slipping.

So I have no idea. Judging the way it flew yesterday I would swear there is nothing wrong with the clutch, but I bet it will slip the next time I use it.

Any ideas?

[DCL]

Not familiar with the car but does sound like there's a mismatch of parts, particularly if it's eating release bearings. Might be worth researching what the default 'factory' spec should be and seeing if there are differences that may be causing an issue. As it get hot and parts expand it may be enough to stop the slipping.

[Mellow7]

DCL said:

Not familiar with the car but does sound like there's a mismatch of parts, particularly if it's eating release bearings. Might be worth researching what the default 'factory' spec should be and seeing if there are differences that may be causing an issue. As it get hot and parts expand it may be enough to stop the slipping.

Thanks DCL although it's not "eating CRB's" . The bearing has only been replaced once and the car is 11 years old now. Plus 7's of this age often suffer the same problem and I understand the replacement bearing is an upgrade. As for mismatch of parts, well it does have a Rover K Series engine mated to a Sierra XR4i gearbox, but then this is how it came from the factory and all the parts were new at the time - enginewise it's only the block, crank and conrods that are original now anyway - again, just like most 7's.

But thanks all the same.

[cptsideways]

Occasional slippage is often an oil leak

[Mellow7]

cptsideways said:

Occasional slippage is often an oil leak

From where?

[radical78]

rear crankshaft seal leaking oil into clutch when engine gets warm

[BertBert]

radical78 said:

rear crankshaft seal leaking oil into clutch when engine gets warm

But they would see that when it was apart for CRB

[WillieLocost]

Clutch cable siezing? That'd be my first check. Then a look at the pressure plate springs.

[Shaun_E]

Is it dry-sumped? If so it is possible that the clutch release fork is bent or broken (might even apply to a non-dry-sumped car). There was an updated stronger version available.

[ewenm]

Check the clutch cable routing. The clutch on my car went from heavy to lovely and light when we replaced the clutch cable and trimmed down the brass section that secures it through the pedal box. It could be that the cable isn't allowing the clutch to engage fully sometimes, possibly due to a knackered cable or a dodgy route.