Clutch reteach worked nicely!

[markinnz]

I had a thing with my 450 where the car would gently surge up and down when underload (trying to accelerate in 6th going up a hill for example), I thought it was maybe something like a crack somwhere and it was leaking boost and chalked it up to something to find and fix.

But I just ran the service option to reteach the clutch the bite point (load point ?) and the problem has now gone! :-) So guessing it was more likely a slipping clutch ?
Probably been doing bad things to the poor thing fthe past year!

[tolsen]

Is that you playing with your £30 Delphi?

[markinnz]

that's it yes .. good value if your morals can ovelook the "perfectly legal, nothing dodgy to see here" software that comes with it :-)

I only needed it to do the key programming stuff, doing the bite point teach and clutch fork calibration is a nice extra ... might look for some newer dodgy software to see what else it can do extra.

[heinkeljb]

It is likely that you have a crack in the turbo manifold if it surges when under load. It is quite possible for those "cracks" to become filled with soot and therefore the surging disappears - but it will come back at some point!.
John

[tolsen]

A new manifold is the only cure.

[markinnz]

OK .. we shall put peoples remote diagnostic skills to the test :-) I'll be taking the back of the car off this weekend and take some pictures, what external signs would there be ?

[tolsen]

I think unSmart manifold cracks are quite visible from below.

[heinkeljb]

There can be cracks inside the wastegate section which are not visible from the outside, there can be such hairline cracks on the outside that they are difficult to see unless they are full of soot or you use a crack detection liquid which fluoresces under Ultra violet light.
John

[Buckster]

I was convinced I had cracks in the manifold on my 450 but the surging turned out to be a damaged wastegate actuator. I think the cast manifold can be quite deceiving when you examine it.

[markinnz]

Still no surging after a month :-)

[mccsmart2002]

A typical crack in the exhaust manifold looks like this. Clearly visible at this stage, there are probably more internal ones too.