Another one for suggestions, please!! My Sept 2005 Octavia Estate 1.9tdi periodically produces a load tapping noise from somewhere in front. It goes for miles without appearing, then suddenly starts up, and is loud enough to be worrying; it doesn't happen on the overrun, only when the engine is pulling, but it makes no difference whether it is pulling hard, or just cruising gently. The tapping is not related to engine speed, but seems more related to wheel or drive-shaft speed. The only thing which seems to get rid of it is to negotiate a small roundabout quite fast! I guess that means that it goes away after the car has had significant lateral force imposed (I think to the right, i.e. the car has turned left). I have not been able to get the noise to start up when I want it to, and I can't see anything loose. Any suggestions?

Tough one that. Intermittent noises are a real bugger to diagnose, especially as they NEVER appear for your friendly Skoda techy.

Does the noise appear in a certain gear or any gear when accelerating?

As its relative to the speed of the wheels I would concentrate on the final drive system. The components that take the most stick would be the wheel bearings and CV joints. Have you had a listen out for dodgy CV's? lower the windows and do some full lock turns forwards and in reverse. Listen out for a clicking/grinding/groaning noise from one of the front wheels. Also do a visual check on the rubber boots covering the CV joints. See if one has split and/or come away from the inside of the hub.

Tis' a shot in the dark but it can be eliminated quite quickly.

While checking the boots, give random components a shake and see if anything knocks or rattles, could be a perished rubber bush or something similar.

I'd also look at the tie rods and front wishbone bushes

Thanks for these suggestions - I will check what you suggest, but it is quite difficult seeing anything without removing the undertray, which looks like a pain in the proverbial without a lift. The mystery really is that the noise disappears so completely when I make a sharp turn; I wonder if it could be something like a loose engine mount which allows the engine/gearbox to move sideways to the extent that a driveshaft coupling just touches something, or maybe some other component which is loos, and falls into contact with a coupling.