No, it's not normal for that big a difference.
Assuming you have an impeller that is in good shape and not over 3 or 4 years old, you may have an elbow or manifold plugging up.
I have a 1997 Mercury 5.7 GM with an alpha out drive. One side of the engine is hotter than the other. The engine doesnt over heat and runs great but one of the exhaust manifolds and the riser is cool to the touch and the other side is so hot you cant touch it. Is this normal? The only reason I ask is because I think that the wiring harness on the hot side melted and then shorted out leaving me stranded.
I just checked the impeller and thats good (I installed it a little over two years ago) and I just pulled the thermostat housing and thats clear. I think I might have a clog in the intake or head. Do you have any ideas on where to start?
