Metallic 'tapping' noise at speed

[leon cupra r]

My friend owns a private road, and I have just been down there to check my car can still drive at speed, and when I get over about 90mph, there is a horrible 'tink, tink, tink, tink' sort of noise, which sounds to be coming from somewhere around the front passenger footwell...

There are two situations when the noise occurs - one is if you are driving hard up to 90mph, when you take your foot off the accelerator to change gear the noise will start almost instantly, and the second is if you are accellerating gently over this speed, the noise does not seem to start up until around 105-110.

Once the noise has started, it carries on, regardless of engine RPM, being in gear or neutral, clutch in or out, and carries on untill speed drops back down below 80-90 region.

The only things that I can think which may have caused it are - with the recent bother I had doing an oil change, there were not enough screws on the engine undertray to fit in every hole, so these may have been replaced in different areas, possibly leaving the engine tray loose in one area which is tapping something metallic under the wind force at such speeds (but dont think this explains the hard/soft accelleration differences)

and, I have just washed my car for the first time using a hosepipe, and wondered if the water that has got in the exhaust was being superheated with the high EGTs after the accelleration and the ticking/popping noise was the water boiling... however this does not explain the noise carrying on when clutch depressed and engine returns to idle at the high speeds....


Does anyone have an explanation for this, and any idea whether its dangerous or not?! Engine seems to be running fine, and apart from the wheelbearing type noise I've had for a while, which I hope to be getting looked at next week while I have time off work, Don't think theres much else wrong with it!

Oh, and before anyone asks, I've checked the little jacking point covers on the sills!

Thanks

Ben