My MY98 has just had a major engine overhaul consisting of new piston No 3 (or 4), a new clutch and a new flywheel to cure piston slap and clutch judder.

Since its return, it has developed a new fault - overboost cut-out during hard acceleration. When I first noticed this, I discovered a disconnected hose (from the wastegate actuator t-piece to solenoid). I reconnected it and everything seemed ok. The problem then returned 2 days later. It then turned out that the afore mentioned t-piece was a non-standard replacement and had melted causing a leak. I informed the dealer who has ordered a new t-piece and hoses but as a temporary measure, has replaced the melted t-piece with another plastic one. Additional it was wrapped in foil to protect it from heat. I thought that it would ok until the correct part could be fitted and most of the time, it is. Hard acceleration through all gears except 5th is normal, but in 5th the overboost cut-out intervenes. I've checked all the connections and they seem ok. The t-piece has not melted.

I'm worried that even once the t-piece and hoses are replaced, the problem will still be there.

Oh and the other odd feature, the boost onset seems variable. One minute its as if the cars got a PPP and the next its sluggish on pick-up.

I'll be visiting the dealer tomorrow to get the t-piece and hoses changed.

D.