Spun bearing???

[sigep0435]

I was on the lake the past weekend, and had been cruising for about an hour when all of a sudden, out of nowhere with no precursor, moderate to loud clicking noise, and immediate loss of power. I cut the power about 10 seconds after the noise started. Question: Does this sound like a spun bearing, and if so what can cause it? The oil level was a tad low, but well above the ADD line. And I had not exceeded 3000 RPM that day or any other day, b/c for some reason, since I bought the boat I couldn't get over 3000 RPM. And if worse comes to worse, a friend of mine will donate a car motor to use as a replacement. Is there any problems with mating a car engine for marine use? It's a 89' OMC 4.3 V6 by the way. Thanks!!!!

 

[tommays]

Re: Spun bearing???

with an I/O drive many times you have to remove the drive to be sure its a motor or drive problem<br /><br />eather one can make nasty noise and cause a sudden power loss<br /><br />tommays

 

[sigep0435]

Re: Spun bearing???

I'm not hoping for one or the other, b/c either way it looks like I'm screwed. But would a drive problem make the engine sound like it spun a bearing, and after it happened, I tried to shift and as soon as I did, it quit. I've been noticing the "clunk" that is described in Stuart's help page, like the gears aren't completly engaging until I'm under way. But it only occurs maybe 5 or 6 times in 100. I'm sorry to drag this out but I'm just trying to get some prelimenary info before I have to take it in and pay out the a** just to find out what the problem is.

 

[tommays]

Re: Spun bearing???

its not a big deal to pull the drive your self if you pick up a service manual<br /><br />its the only way to no what to fix but it sounds more like drive than motor<br /><br />as far as motors the big difference is gasket material and brass core plugs <br /><br />you would need to bolt on all the marine parts from the old motor ,electric,fuel ect are all marine only

 

[sigep0435]

Re: Spun bearing???

Thanks tommays, one more ? and I'll leave you alone. I'll pick up that manual and call on my mechanically inclined friend, but would it hurt anything if I start the engine without the drive on? And I forgot to mention that when it happened, we unscrewed the oil fill cap and smoke was coming out. Not alot, but it was kinda like somebody dropped a cigarette in there. (best visualization I could think of)

 

[BF]

Re: Spun bearing???

yes, sure sounds like an outdrive problem to me too. Anytime the engine is running, it it turning the driveshaft running down the leg and the gears in the lower unit. Shifting to neurtral just disengages the propshaft from the gears in the lower unit.<br /><br />I'd drain the gear oil in the lower unit and see what comes out... filings and chunks would be bad news. The fact that your drive was clunking for some time before this also points to something not being right with the outdrive.<br /><br />I don't know about starting the motor without the outdrive... but I'd guess when you drain the lower unit, you'll find out it is a lower unit problem. If so, brace yourself for a pricey fix. In these parts, it's rare to get much done for < $2000, usually more. Those gears and bearings are expensive.<br /><br />good luck

 

[sigep0435]

Re: Spun bearing???

O well, I was hoping for the motor to be the prob, b/c at least I have one to use for free. But I'll check that drive as soon as I can, and keep my fingers crossed. But thanks a lot BF and tommays, the drive would have been the last thing I would have thought to check. Thanks again!

 

[jeff13601]

Re: Spun bearing???

You can run your boat without the drive but it still needs water. Find where the inlet hose comes to the t-stat. Unhook that line and direct feed water into the engine with a hose

 

[olbuddyjack]

Re: Spun bearing???

had been cruising for about an hour

At WOT? If you can only get 3 grand from the motor you could be lugging or running lean and burnt a piston, causing the knock. Are you getting a lot of blowby?<br /><br />You weren't that low on oil to cause a bearing to spin.<br /><br />Do a compression/leak down test if the noise is still there with the drive off.

 

[Haut Medoc]

Re: Spun bearing???

You should do what tommays & BF say but, I think olbuddyjack is onto something. The sudden loss of power, the noise & the smoke from the oil cover sound like a burnt piston to me....Time for a compression test.......J

 

[sigep0435]

Re: Spun bearing???

I was at more like 2800-2900 that day, but yes at wide open throttle, 3000 was all I could get. And would a burnt piston create the smoke that came out when we removed the oil fill cap? I had a feeling too that a spun bearing didn't sound right b/c I wasn't that low on oil, but everybody kept telling me that so I went along. And would the comp/leak down test prove my problem? THANKS!

 

[Haut Medoc]

Re: Spun bearing???

Yes & yes...J

 

[Silvertip]

Re: Spun bearing???

If you spun a bearing, the oil pressure gauge would likely provide an abnormal reading. Engines can spin a bearing at any time regardless what the oil level is. Bearing noise is also not the "clicking" sound you describe but rather a dull "knock". A less pronounced rapping coming from higher up on the engine would likely be valve noise due to a broken valve spring, loose rocker arm, bent push rod, etc. Bearing noise comes from much lower in the block.