Mercruizer 5.0l V8 running hot on the Starboard side. - Maxum Boat Owners Club

RoyR · 09-10-2009, 08:50 PM

Last week I had the impeller replaced by Hipp Marine, read too many overheating threads. Took the boat out to Lake Mohave this weekend and the starboard side exhaust manifold is running significantly hotter to the touch than the port side.

I seem to recall this may have been the case before, but it was steaming the water this weekend. When I launched the boat the next day, I only put the stern in the water, started it, and at 1000rpm, both sides was pumping a steady stream of water?

M2O Marine removed the risers earlier this year for inspection, and they looked good. Any ideas? I don't want to take the boat back to Hipp Marine, cause the first thing they said when I called them was to replace the manifold????

Serial Number: 0M353341

PS. Before I was able to get 55mph, this time only 48mph?

zt260 · 09-11-2009, 12:48 PM

You could try a new thermostat just in case it isnt opening all the way

ash

seapuppy · 09-11-2009, 01:54 PM

well...this has been brought up on other threads on other sites....the stbd side runs hotter and it is significant but nothing to really worry about...to verify the temps...get a cheap laser temp reader from say ...harbor freight..bout 30 bucks....and check the temps...believe it or not ...won't be but about 20 degs difference.....the water starts the on the port side and goes to the stbd...by then it's heated some and is quite a bit hotter than the port side....if your getting good water flow out the drive...then it should be ok...
both of my engines are the same and they are new...

SP :hello:

RoyR · 09-11-2009, 02:40 PM

I know, same thread on iboats....from the diagram, it looks like the water flows into the engine via the water circulating pump, then out on the starboard side, through the thermostat out to the exhaust manifolds, so that may make sense....will get the IR gun on it this weekend. Hate being ignorant about this stuff!!!!!

RoyR · 09-14-2009, 04:53 PM

Met a new mobile boat mechanic that is reasonable and seems to know what he's doing. Invited him to come over to have a look, dropped the stern into a bucket of water and ran the motor for 10 minutes with no sign of over-heating....WTF? NExt time I go out, I will take the IR temps, just so that we have them for reference.

racer2c · 09-14-2009, 08:49 PM

Maybe some temporary blockage that worked it's way out? What does your engine temp gauge read? I agree with you being proactive, better to fix a suspected problem than call for a tow, but if your engine temp is reading OK, I'd let it rip. Could be why they don't individual riser temp gauges on the dash. :wink: