Merc 470 problems....

imported_Mike_M2

Petty Officer 2nd Class
Joined
Jan 17, 2004
Messages
174
My buddies boat is a pain. One motor broke the camshaft right at the keyway, so i replaced it. Stuck it all back together and she sounds great. Problem is this, it ran for maybe 5 minutes and pulled the valve cover back off. Inside was an oil/water mixture and it was definately originating from the pushrods. Every rocker had a puddle of mixture on top, and i noticed drops of antifreeze on the inside of the valve cover indicating it squirted there from the pushrods. It isn't bad, only a few drops and the mixture wasn't real bad either. I pulled the dipstick and it's solid oil, no water whatsoever. I canceled the Friday launch until i know for sure whats up. It did sit for a long time tore apart. I'm trying to figure out how it gotwater in the oil pressure system. The lifters are new, the pushrods were clean when i assembled. I wonder if it's just antifreeze that got down there during the teardown period now. I'm thinking now i may reinstall the cover and run it, flush, then run and see what happens. Whadya think????
 

Laddies

Banned
Joined
Sep 10, 2004
Messages
12,218
Re: Merc 470 problems....

Sounds like the cam seals behind the w/pump impeller are leaking, you won't be the first person to have that problem and won't be the last--Bob
 

Bondo

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Apr 17, 2002
Messages
71,088
Re: Merc 470 problems....

BTW,...... Anti-Freeze will Not Mix with Oil, like water Will...........<br /><br />The 1st time it passes a Bearing,.... That Bearing is Toast...........<br /><br />Switch it to Pure Water for the diagnosis period......<br /><br />Good Luck......
 

imported_Mike_M2

Petty Officer 2nd Class
Joined
Jan 17, 2004
Messages
174
Re: Merc 470 problems....

The cam seals are tricky and was 100% sure to follow the manual. Heck, even went as far as to check Seloc and Clymers to make sure i got it right so i don't think it's that. I will admit tho, i did install them with a terrible hangover so.....Naw, i know i got them right.<br />Yes good idea Bondo, i will switch over to all water before i run it anymore. Tho i don't see any antifreeze on the dipstick maybe it's shaking off while i'm pulling it out and i don't see it in the oil cause it don't mix...
 

Bondo

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Apr 17, 2002
Messages
71,088
Re: Merc 470 problems....

Drain off a cup or 2 from the base......
 

imported_Mike_M2

Petty Officer 2nd Class
Joined
Jan 17, 2004
Messages
174
Re: Merc 470 problems....

Thanks, it'll be till next week until i deal with it anymore. This weekend is dedicated to my boat, one motor has no starter and the other no risers....
 
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