Help to narrow down my problem

Devildog69

New member
Last weekend my boat overheated :embarsed:... I shut it down within four seconds of motor noise. Let boat cool down over night and tried to start it. Well, it runs but with some noise. See attached video. I am thinking that the internal fuel pump failed seeing we see no flow in the antifreeze. Do you think this could be my problem?

Steve
 
Steve, there isn't enough info here to diagnose but sadly my first thought is major engine damage... First step is do a compression test.... If that shows problems then there is no point going further until that is fixed.

Generally "within four seconds of engine noise" means 4 seconds after it was already too late.... NOT always but usually.
 
first off, what kind of engine?
Second, what kind of noise
third, do a compression test, you can buy a decent tester at any parts store for around $30
 
Devil, I cannot find any link to a video. But from what you've said it doesn't sound good. And did you mean the internal water pump? The fuel pump has nothing to do with the engine coolant. I'm guessing you have an I/O with a fresh water heat exchanger since that's the only way you could have anti-freeze, or am I totally wrong? Regardless, by all means first do a compression test. Second, if it is an I/O, look at your oil dipstick to see if the oil is clean or is a milky chocolate looking fluid. If it's milky brown then I'm thinking at the very least you warped a head and blew a head gasket. And in all cases, it sounds like what caused the problem in the first place was either a failed water pump, a blockage in the engine coolant lines or a failed impeller in your outdrive. There are others here that can give you much better advice, but first things first. Like Smoke and Spare both said, we need to have more info before we can make a semi-accurate diagnosis.
 
After a little digging, I found he has an 87 3.7L 470 MERCRUISER in his boat(dug up his first thread). He has also had some issues with this engine in the past and anti-freeze intrusion at the riser into the manifold from lookign through old posts of his. Not sounding good for his engine if this is the case.
 
Yep, a bad riser will kill a 3.7. I got one in the garage that wasn't winterized and the riser busted dumping antifreeze into #4 cylinder. Took a little work but got it back running. If it ran hot Id check the oil, compression and antifreeze for tale tell signs. Sounds like your impeller may have gave up.
 
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