Mercury 5.7 over heating

[bajamike18097]

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 doesn’t over heat and runs great but I one of the exhaust manifolds and the riser is cool to the touch and the other side is so hot you can’t 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.

 

[Boatin Bob]

Re: Mercury 5.7 over heating

First of all this post should go under the Mercruiser section so the right folks will see it. No it's normal they should be relatively equal in temp, you may have a restriction in the cooling system maybe an old piece of an impellar or a T-stat housing is partially plugged, you need to go through the system to see where the blockage is.

 

[bajamike18097]

Re: Mercury 5.7 over heating

Sorry I didn’t realize I was in the outboard section.