usnavyvet

I'm not an expert, but if it were me I'd try:

1. remove the belt and see if the problem still exists
if not, I'd look at what you're driving to see if something is binding.
2. remove the spark plugs and see if the problem still exists.
if not, I'd say it's normal, if it still binds with the belt and plug out, I suspect you'll
have to open the engine up and check bearings and the valve train for binding.