OMC 3.0

gtaeza

Seaman
Joined
Jun 3, 2004
Messages
54
Previous problem was oil mixed with water (milky oil)now I installed the new manifold I test the boat in the lake for 4-hrs. Now, there's no more<br />milky oil but I'm wondering why the oil is to dark and this is second change oil since the new<br />manifold was intalled. I appreciate your suggestion.
 

cobra 3.0

Lieutenant Commander
Joined
Jul 31, 2003
Messages
1,797
Re: OMC 3.0

What is "dark"...tan, brown, or black? What brand/kind of oil are you using?
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: OMC 3.0

Sometimes I've seen some pretty dark MerCruiser oil right out of the barrel. Just deeper in color than others. Still good oil. (If that's what you're using.)
 

gtaeza

Seaman
Joined
Jun 3, 2004
Messages
54
Re: OMC 3.0

It's a black oil but no water mix. I used Cobra<br />oil sae 30. I'm thinking maybe there still sludge<br />left inside the engine oder head valves.
 

cobra 3.0

Lieutenant Commander
Joined
Jul 31, 2003
Messages
1,797
Re: OMC 3.0

Try an engine flush product that you put in the oil. Use as recommended and drain.<br /><br />Also, a synthtic oil will do the same. It really cleans out most of the sludge...but your old gaskets may start leaking too...
 

gtaeza

Seaman
Joined
Jun 3, 2004
Messages
54
Re: OMC 3.0

Cobra 3.0<br />The head gasket is newly installed after they tested the manifold. Anyway, I will try to pour<br />a new oil and run again this week end.<br /><br />Also do you have any idea that when it goes up to 3000RPM there is a whistling sound coming out and temp. also going up to 185 your suggestion is highly appreciated. They gave this boat free and I upgrade the drive, the water pump still original, the thermostat seems never change yet.<br />but new manifold and riser. 200rpm at 140 temp.
 

cobra 3.0

Lieutenant Commander
Joined
Jul 31, 2003
Messages
1,797
Re: OMC 3.0

Whistling as in air? Or whinning like a strap squeel. Your pulleys should be rust free in the grooves and your belts good and tight.<br /><br />Could be your main water pump on your engine(not the impeller on the drive which should be changed too anyway). The pump would leek if its gone on the engine, but not necessarily. You will need someone to drive and another to listen to where the noise is coming from...obviously with the engine cover off.
 
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