Any idea

On my 02 gt now that it has gotten colder in the morning,Im hearing a knocking on the passengers side of the valve cover and it stop as the car warms up.I was running RP oil 5w-20.So after this started I change back to motorcraft oil and filter 5w-20 and still knocking tell it warms up.Any help or Ideal.Thanks Tony

is it a knock or a ticking sound? could be an injector or valve clatter. try switching to 5W-30.

if it starts acting weird while driving stop driving it immediately. there's a lot that can go wrong in the valve train.

if you can get a video of it doing it then maybe we can come to a better diagnoses. is

if im not mistaken the owners manual on a 2002 gt states that 5w30 weight motor oil should be used. yanceys on the ball on this one

Has your car ever had the TSB applied to it that addresses the valve guide issue on these years of 2V's? I never got it done to mine, but it might have something to do with it.Might have a lash adjuster bleeding down as well. They work alot like the older hydraulic lifters, If I remember correctly.