Join Date: Jul 2010
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Overheating Issues (1GM10)
I've been trying to pull away from my winter marina to my summer mooring but have twice overheated and found myself drifting in the exact same spot 1000ft from the marina.
Prior to the first time, I ran the engine about 30 minutes before pulling away (idling, full rev, and in gear). I check the water flow out the exhaust routinely. After pulling away from the dock at about 2800 RPM's I got an alarm after about 2 minutes. I anchored and took apart the impellar but it looked perfect. After replacing it anyway and starting the engine again I saw no water flow and shut things down.
I called up a pro and he diagnosed it as an intake hose that was too long (it was long, it came form the PO that way, but gave me no problems last season). He confirmed that there was no flow at first.
So I tried again, checked the engine at the dock again, and pulled away. I ran at 2800 RPM's for a minute, I checked for water flow (at this point I was mostly just checking for water or no water, not evaluating how much) and got an alarm at the exact same spot. This time I waited it out while drifting slowly until the engine had cooled and ran it again. There is flow, I can run at low RPM's, but I'm suspecting it's not as much as it should be.
Another fact is that an impellar failed in the middle of last season and I never recovered 2 or 3 of the blades.
So any thoughts? I'm thinking the cooling system has an obstruction (possibly an impellar blade) that is restricting flow and intermittently stopping it. Is that reasonable? Other ideas? On the 1GM10 where is there likely to be an obstruction in the system (note I have no strainer)? Ideally I'd do this myself but given that I'm tight on time I'm debating whether to call the pro (again) or take a day off work to look at this myself.
Last edited by asdf38; 06-16-2011 at 11:47 PM.