05 1.8 Ticking Noise Under Power - Bromptonaut
1.9 IDI Berlingo has acquired a tick tick noise. Sounds like a flint in the tyre but is proportionate to engine rather than road speed. Probably about quarter engine speed. Audible when driving with widows open but cannot replicate stationary as it seems only to be present under load.

It's going to the garage next week for a new rear exhaust box and I'll get this looked at while car is there but can anybody suggest anything more informed than my ideas above?

TIA
05 1.8 Ticking Noise Under Power - oilrag
One of the injectors?
05 1.8 Ticking Noise Under Power - Wurzel83
When they have it up on the ramps, get them to check the condition of the Auxillary Drive belt and look for torn bits. I know you mentioned that it happens when underload but its worth checking as the belts can be 1/4 the length of the circumerence of the crankcase pully hence quarter revs.
05 1.8 Ticking Noise Under Power - madf
Check exhaust manifold gasket.
05 1.8 Ticking Noise Under Power - Bromptonaut
Thanks to those who responded.

At first the auxiliary drive was suspect as there was a possible "nick" in it. Turned out however to be the cambelt being forced out of alignment by a damaged pulley. Belt was "chattering" against crankshaft pulley and (I asked for it to be retained) it was starting to split. £700 bill for it and exhaust but I think I had a close escape.