IME any oil thickens up with mileage; there are a number of comments on here from me about the engine being slightly tappetty on a cold start in the month or 2 before service.

Ken, do you have any thoughts on a tired oil pump causing the problem, its literaly only the first few seconds of running & is definately a lot worse on very cold mornings, again I assume the oil being colder is harder to pump

Ken, do you have any thoughts on a tired oil pump causing the problem, its literaly only the first few seconds of running & is definately a lot worse on very cold mornings, again I assume the oil being colder is harder to pump

It makes sense in theory, but you rarely hear of worn-out oil pumps as a rule. That said, hydraulic tappet engines aren't the rule in Europe either.