Simoniz
Petty Officer 1st Class
- Joined
- Dec 30, 2007
- Messages
- 242
Took my boat out today and managed to run it aground slightly, luckily only at idling speed and the lake bottom is basically mud mixed with a bit of sand.
We pushed the boat off the sand bar and I had a look round and there was no damage to prop or skeg, and all the trim and steering seem ok.
However on starting up and leaving the area, the temperature gauge crept up briefly to around 180F, (normally runs just under 175), then quite rapidly dropped to around 125F where it stayed, so I guess I had picked up some crud into the cooling system.
Running back to base, the exhaust temp as felt with the hand was normal, and leaning over the back to test the water coming out of the relief ports showed the cooling water which was being dumped overboard to be normal, ie quite warm but easily bearable with a bare hand.
When I had the boat moored up, I removed the top cover on the thermostat housing and sure enough the stat was jammed a couple of mm open, although I couldn’t see much of anything which could be jamming it. My guess is that the mud which got picked up initially held the stat closed for slightly longer than usual, until the bi metallic spring forced it open, then whatever was in there held it open just enough to over cool the engine.
It looked to me as if the thermostat is an integral part of the housing, but that would make no sense, and the manual I have talks about lifting the stat out. It didn’t seem at all loose, but maybe it needs prying out, possibly destroying it in the process?Is the stat a separate part which should just lift out? Edit to add, Ive now found an exploded view, which shows the stat as a separate part, and it seems theres a sleeve above the stat in the housing, how does the sleeve come out? Also if it comes out, or if I have to remove the entire housing, will a rinse off in hot water sort it, or is it buggered, do we think?
All advice gratefully received, as ever!
Mercruiser 3.0l with Alpha 1 Gen 2 drive, year 2001. Eng No OL634881
We pushed the boat off the sand bar and I had a look round and there was no damage to prop or skeg, and all the trim and steering seem ok.
However on starting up and leaving the area, the temperature gauge crept up briefly to around 180F, (normally runs just under 175), then quite rapidly dropped to around 125F where it stayed, so I guess I had picked up some crud into the cooling system.
Running back to base, the exhaust temp as felt with the hand was normal, and leaning over the back to test the water coming out of the relief ports showed the cooling water which was being dumped overboard to be normal, ie quite warm but easily bearable with a bare hand.
When I had the boat moored up, I removed the top cover on the thermostat housing and sure enough the stat was jammed a couple of mm open, although I couldn’t see much of anything which could be jamming it. My guess is that the mud which got picked up initially held the stat closed for slightly longer than usual, until the bi metallic spring forced it open, then whatever was in there held it open just enough to over cool the engine.
It looked to me as if the thermostat is an integral part of the housing, but that would make no sense, and the manual I have talks about lifting the stat out. It didn’t seem at all loose, but maybe it needs prying out, possibly destroying it in the process?
All advice gratefully received, as ever!
Mercruiser 3.0l with Alpha 1 Gen 2 drive, year 2001. Eng No OL634881
Last edited:
