Only noticed this this morning on the way to work. Standard MY97 Turbo. I've had it for approx 2 weeks and no probs.

Noticed in traffic this morning if I gently touch the accelerator, not enough for the engine sound to drown things out, I hear a tap tap tap. Doesn't matter whether the car is in gear or not, nor whether clutch pedal depressed or not.

I would describe the sound as a metallic clicking. It's frequency doesn't seem to increase if I press the accelerator more, though the engine noise soon drowns it out, making it hard to tell.

From the driver's seat I would say the sound comes from somewhere in the vicinity of the turbo unit i.e. somewhere in front of my right knee, but I would need to get someone else to help me verify this.

Given this limited detail, could anyone suggest tests or methods I could use to narrow this down so I can decide if its serious or not?

This may just be the turbo wastegate actuation control solenoid ticking away to itself. This unit is (probably) mounted on the front facee of the left hand suspension turret under the bonnet.

Sounds exactly like the solenoid. Unfortunately boost pressure is controlled by pulsing the solenoid open and closed. Under certain conditions, just above idle when warm, it makes a tappety sound which can be very annoying. You can wrap it up in sound deadening felt, or something similar, but it does get hot and should probably be open to air. I complained to my dealer but have not received a satisfactory solution.

I think later cars (MY98 on) have a different type of solenoid which overcomes this problem.

My car (oct 1998 model) also makes said noise, guess it's not serious anyway.

Don't worry about it - it is the noise of the Solenoid valve opening and closing at low revs. Thanks to cost control measures the solenoid isn't the silent type.

I had a positive ID of the noise carried out by the dealer, who said that a lot of people mistook it for a driveshaft type clicky noise.

Rgds,

Alex

This wastegate solenoid is mounted on 2 rubber mounts,purpose to absorb the clicking or pulse from the solenoid.These mount may have been damaged or not properly seated and this is why you can hear the clicking noise.