1.9TDi noisey top end

After a full service at my Skoda dealer the top end has become very noisey from cold through to normal temperature.They have told me 5w/40 oil to VAG spec was put in but after starting from cold and driving off you can hear the cam and all the hydraulic tappets all the time until its warm.Its not actually metal to metal sound but just very pronounced noise.It didn,t do it before the oil change so now iam a bit concerned about it.Any ideas what this could be or why its happened?