Bought OMC 3.0 with outdrive off

headstartnana@aol.com

Seaman Apprentice
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Apr 17, 2006
Messages
36
The guy said it was knocking and took it "somewhere" and they pulled the outdrive off. Said that it was a rod knocking. <br />Need opinion here....should I reinstall outdrive and diagnose from that point (saw a posting where the guy had a "knock sound" and it wasn't the rods/mains.<br />Do I have to reinstall outdrive to diagnose? water issues and seals...etc.<br />Thanks for any/all help
 

cobra 3.0

Lieutenant Commander
Joined
Jul 31, 2003
Messages
1,797
Re: Bought OMC 3.0 with outdrive off

Which year OMC?<br /><br />You need to insert your garden hose into the water inlet from the outside where the drive was attached. You should not run the engine without water for cooling.
 

THE BEEF

Chief Petty Officer
Joined
Jun 11, 2005
Messages
432
Re: Bought OMC 3.0 with outdrive off

Hello MEB<br />Welcome to iboats.<br />Ok, I have an idea. :rolleyes: If you want to run the engine to check for a problem I believe there is a feed water hose that comes from the intermediate housing if it's a stringer. you should be able to hook a garden hose to it and run the engine with out the drive on.<br />Beef :D
 

Don S

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Messages
62,321
Re: Bought OMC 3.0 with outdrive off

Just start it up with the drive off. You won't need water for a few seconds of running to hear a rod knocking. And you can't damage the impeller cause it's in the drive. IF you want to run it more than that and need cooling water just hook a water hose to the engines water intake hose that attaches to the transom shield.<br /><br />The reason for them pulling the drive is to eliminate ujoints, or the drive as the cause of the noise.
 

headstartnana@aol.com

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36
Re: Bought OMC 3.0 with outdrive off

Thanks guys! I was concerned about doing any additional damage to the engine. The previous owner told me they removed the outdrive in order to pull the engine. I know cars but not boats. I knew that I could run it long enough to hear a rod knock without water but I wanted to be flexible in case I didn't hear a knock. I keep seeing in the forum where the exhaust flapper can make a similar noise. Thanks again for the help!<br />I'm sure I'll be back.
 

headstartnana@aol.com

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Re: Bought OMC 3.0 with outdrive off

Went to crank over the engine and started to try turn it by hand and it is stuck. Will let you know when I can get it to turn over
 

jch7450

Petty Officer 1st Class
Joined
Apr 13, 2003
Messages
230
Re: Bought OMC 3.0 with outdrive off

Gotta be carefull checking a knock in a 3.0. I had one, It run great with the muffs (No load)<br />Put in the water , went out about 1/4 mile and it sounded like it was going blow a rod out the side. The dealer said ( OH (*^%)&)(7@$) lol
 

cobra 3.0

Lieutenant Commander
Joined
Jul 31, 2003
Messages
1,797
Re: Bought OMC 3.0 with outdrive off

You tried to turn it clockwise ...right?<br /><br />Any how, looks like it's time to pull the head off and inspect.
 

headstartnana@aol.com

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Apr 17, 2006
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36
Re: Bought OMC 3.0 with outdrive off

The oil is clear. <br />They left the s/plugs out so the pistons were stuck. Couldn't turn it either way.<br />Since the last posting, I've done a complete tear down. As far as the "knock", four of the coupler bolts were finger tight. The other 2 were barely tight. But to be sure, tore it down the rest of the way. Rods and mains are perfect. Wrist pins are good. No broken pistons/rings. BUT did find headgasket blown between 2 & 3. And what has me most worried..... the block has a crack above the port side front freeze plug. The previous owner said that he had ran it with problem before.<br />The engine is .030 over and the rods/mains are std.<br />I'm wanting to know if an automotive 2.5L will bolt up.<br />Thanks
 
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