140 Mercruiser: Oil/water mixing

[eric416]

I was on my way in from the last cruise of the season and I started to hear a slight knock. When I got in, I saw oil/water (looked like a milkshake) dripping out of the tube that goes into the carb and comes from the valve cover. Where should I begin to diagnose my problem? Im thinking a gasket blew but not sure which one.

 

[Jeepster04]

Re: 140 Mercruiser: Oil/water mixing

Checking the compression is a great place to start.

 

[ziggy]

Re: 140 Mercruiser: Oil/water mixing

this may help ya get going it the right direction...

http://www.boatfix.com/merc/Bullet/01/01_13.pdf


start by getting the water out of it... right now... you wait to long and whatever ya do will be academic...

 

[Bifflefan]

Re: 140 Mercruiser: Oil/water mixing

Checking the compression is a great place to start.

Compression checks will not tell you if there is a leak from water to oil tho. You can get a good reading on compression and still have a bad head gasket.

By the way, if its already knocking then you need to pull it and look at the bottom end anyway. This is one of those times when your in for a penny, in for a pound.