Thanks fellas, some great advice here.
Truth is it could be any one or combination of the problems you have listed for me.
The mileage on the car shows 102,000 but the engine was replaced recently (Not sure how many miles that engine had done).
The matrix used to bubble with the old engine, but doesn't now...I don't think...maybe I'm just used to it!!!
The dial is definately moving because I checked that out in the summer.
The other things, I haven't checked yet, but will now.
Thanks for the again for the advice.