When driving my digi at 70mph+, the engine makes a strange noise. The noise seems to go up and down in waves rather than a continuous drone. In the last 12 months the car has had new dizzy cap, rotor arm, spark plugs, ht leads and had an oil and coolant change. I think it needs to be set up properly as in rubjonny's guide, which will be done as soon as I can afford the equipment, but I would like to know if it is something else causing this so I can look at that in the meantime.
