[tet68]

Hello there
I have an question ,my engine an 5.7 350 magnum ,one side gets hotter then the other side
Had this winter an major overhall and every thing works well
Had an extra compresion test but that was ok ???

Thank for the help!!!

greezz Rick

[dieselwiezil]

mine does the same but, i believe its the port side. I will reinspect after I put my drive back on. It hasnt run since last November. Must be corrosion...

[mikeyt]

From what i've read on the subject it is normal for one side to be hotter than the other and that Mercruiser themselves state that up to 30 degrees difference can occur. There may be some corrosion in your manifolds & risers, particularly if you operate in salt water though. If that's the case then you want to have them inspected. Water coming out of the thermostat housing is not divided equally between the starboard and port side. Water takes the path of least resistance, and most will go out one side. The other side does get water, but not the same amount. Hence, one manifold (or exhaust elbow) will be cooler because of more water flow than the other side with less water flow. This should be more noticeable at lower speeds. At higher speeds, more water is flowing and both manifolds get closer in temp to the touch.

[Firth's Impression]

Mikeyt is exactly right on this one. It all comes down to a waterflow issue. Typically it's Portside that will run a bit hotter than Starboard. If it's considerably hotter (to hot to touch) then you have a waterflow issue. Common occurance is corrosion or also common is old impeller particles. I have a 496 MAG in my Z302 and I was having these issues. The old owner mentioned that the impeller was recently replaced but when I took the output hose off the water pump and put the shop vac to it, I sucked out several small particles that were most likely hung up in the transmission cooler or oil cooler. I then disconnected the water line above the oil cooler and flushed it backwards with a water hose to be sure I was clear. After this, both sides ran nice an cool. As Mikeyt mentioned, water will take the path of least resistance but if there is additional blockage then you might not be getting enough water to keep 'er cool. It's a quick and easy maintenance procedure. Try it.

[dieselwiezil]

I only noticed mine as I was flushing it out. Once I replace my bellows, trim senders, impeller and drive reinstalled I will be back on the water. (I'm still in a good mood that my u joints,gimble bearing and drive were in such good shape)I actually got $$$ back from the boat place!

[mikeyt]

Originally Posted by dieselwiezil

I only noticed mine as I was flushing it out. Once I replace my bellows, trim senders, impeller and drive reinstalled I will be back on the water. (I'm still in a good mood that my u joints,gimble bearing and drive were in such good shape)I actually got $$$ back from the boat place!

Any time you get money back is a good time!