9th Nov 2011, 20:20

The tapping could be either the injectors, or there could be a problem with the valves. You should get it checked ASAP, as it could result in serious damage if it's the valves. A lot of the time it won't be a problem, but you wouldn't want to take the risk of letting it ride.

11th Apr 2013, 15:54

Hey mate, I had a tapping noise in my 1995 VR Commy. Well it was more like a thump or a knock, and I found out it was coming from the rear of the engine. I never found out what it was. I replaced the engine; as I'm a mechanic, it was a few hour job, but as I was stripping down the engine, I found that the balance shaft had a rock in it, and also the timing chain was quite loose and noisy.