grey oil

Hey again; 1972-78 Mercruiser 165hp Serial number 3465185. Im not sure why things happened and the ways to remedy grey thick engine oil.
i worked on tuning the engine this year with new points, condenser, coil, spark plugs and wires. I cleaned the carb with carburator cleaner as per the instructions on the can. When we went out for the day everything ran tip top. I had only a maximum of 3800 rpms but everything seemed find. When we went to return home the engine coupling must have broke. We had no reverse or forward. We tried many things before getting towed in and we noticed eveything was very hot and the temp guage was red. I really dont know if the oil got thick from overheating and if just draing the engine oil is sufficient. I have to get the engine coupler changed and really hope that is the worst of it. I never knew about greasing the coupler and checking alignment, and i have hit a sand bar before. I think that might have been the start of everything. Any ideas guys.

Re: grey oil

Overheating the engine would turn the oil black not grey. Grey is caused by water intrusion. If it got "red" hot you may have blown a head gasket, cracked a head, or cracked the exhaust manifold. You probably burned all of the rubber exhaust components. I would change the oil, pull the out drive, remove the raw water inlet hose to the engine, and connect/rig your garden hose to the inlet fitting on the engine (turn the water on) and start the engine. See what happens.

Re: grey oil

What would i be looking for. Will i see water?

Re: grey oil

Well, it seems to me that if the coupler broke then you would not be circulating raw water from the lower unit and continuing to run the engine would cause the overheating issue. IF, and that may be a BIG IF, that overheating did no damage then you MAY be ok.
The oil contamination you have could be water, though my experience tells me that water in the oil makes the oil look more like a milkshake and the oil level increases from the added water. Or it could be from the carb cleaner you used if you sprayed a lot down the throat of the carb with the engine off.
On the other hand, if that overheating caused a failure (head gasked, cracked head, manifold, etc) then that would certainly contaminate the oil.
The first thing you need to do is to change the oil and filter.
Then connect a water supply to the engine and run it up to temp. If the engine is allowing water to contaminate the oil then the oil will again change colors and the oil level will increase. If the oil does not signifigantly change color, level or consistancy you may be ok. Keep in mind that if there was still contaminated oil from before ther may be a slight change in color but level should not change.

Re: grey oil

so i ran the engine for 10 minutes. the new oil looks new with no discoloration. It did not seem to raise either. Did i run it run it long enough?

Re: grey oil

Did you get it up to operating temps? If not the t-stat will not have opened and allowed water to circulate. You want the water to circulate otherwise you're not really checking anything.

Re: grey oil

i went and tried it again. This time it ran for 15 minutes. The temp needle was almost in the middle. Was that long enough? The oil didnt change colour and the level didnt change. I hope i can assume it is ok and i can just go ahead and replace the coupler.

Re: grey oil

Hopefully, you are good to go. Once you're back togeather again and running I'd keep a close check on the oil to be sure it's not related to running in the water.