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View Full Version : Why Leaking Head?


MikeyOrange88
07-16-2012, 09:09 AM
Okay, new to forum posting, but have read many other threads related to this subject.
Boat: '88 Mastercraft Tristar 190 closed bow with Ford 351 W engine, 605 hrs. Boat & motor are in great condition. I'm second owner (since '98), both of us having kept boat in garage. The problem started last year when I noticed small drops of water oozing out of the head just above the lower head bolt at #8 cylinder. I say oozing because it only drips approx. every two seconds or so.
To my knowledge I've had no overheating issues. We're in NE Florida near the river and don't think it was a freeze issue, although I don't routinely drain the motor in winter. Initially kind of ignored it as everything seemed to be running perfectly. I did rebuild the carb this spring (second time) and changed the oil (no water). After reassembly it started right up and ran fine (at least in the driveway). It has gotten progressively worse, and while out a couple weeks ago wakeboarding, it seemed to be sputtering a bit at speed, but idled okay. Tested compression with both all plugs in and all plugs out with screw-in type tester. All cylinders were 130-132 with exception of #8 which was only 125, but it still seems within tolerance. No water in oil that I can see as it is still very new and amber colored. Engines runs at a constant 150 or so. The only overheating issue I can see, which I thought to be normal is after the motor is ran and then turned off, and when restarted several minutes later the high temp. alarm sounds, temp. over 200, but immediately returns to 150 after two seconds with water circulation.
I was preparing to tear down engine to address head issue, but after checking compression, I wasn't so sure. I guess the question is, can a leak/crack develop in the head that dumps water into the cylinder, but leaves the head gasket intack, at least for now. Assume it still needs to be torn down, heads inspected and repaired, or replaced? Any suggestions or help would be greatly appreciated.