GTI Clocks

I  have had to recently take out my speedo/clocks due to a buzzing noise which made no sense as the system worked perfectly, this was suggested at the same time as having a new oil pump put in.  The gti clocks were replaced by a spare set i had from a cl model, driving today and the buzzing returned for a few minutes which made me think that perhaps the original gti clocks were not the problem !!! I would like to know if there is a common problem or fault that i'm missing here.

Any help would be great.

If the buzzing happens and the oil light flashes while driving and above 2000rpm then its either a worn out oil pump (low oil pressure) or the oil pressure sensor is faulty, the one above the oil filter.

After a new pump was fitted I'd swap
The sensor. I'd also get an oil pressure test done.