115 4 st Mercury , dirty oil

[big foot]

Have a 2003 115 Merc with only 250 hrs , last year with 50 hrs on last oil change oil came out totally black with about a 1/2 qt over full with what looked like mixed with some fuel , a small amout of clear water came out first when oil was drained , this year with about 50 hrs on this oil change the oil came out again extra black , again looked like some fuel mixed in as the level was about 1/2 over full mark also with a 1/2 cup of clear water first when oil was drained , Any suggestions or advice would be appreciated , thanks ( motor does run great with the only problem that it sometimes dies when comming off full throttle ) Forgot to add I use Castrol GTX 10w40

[Empire]

I have the same engine and have had the same problem.

How often do you run the engine long enough to heat up the block to full temp?

If you troll a lot with that engine you will get condensation in the crankcase. Running at 3500rpms or more for about 10 to 15 mins should burn off water and fuel that is in the crankcase oil.

[big foot]

Almost all the hours are over 3000 rpms , with the only idle time is into the boat ramp or slip . Merc says the condensation is nornal ? I can live with that I guess , but why should the oil turn so black in just a few hours ??

[Empire]

Do not worry about engine oil turning black, that is normal and not an indicator of wear. Read this:

http://www.motor-oil-engineers.com/oilcolor.htm


I have my biggest problem with the engine "making oil" when I run trolling speeds in early am, on cool moist mornings. Be sure to change the oil regularly and you should not have any problems.

[retaliate]

My 2002 merc/yama 115 has had blacker than expected oil since the very first year also, don't know why, but haven't had a single problem with the Motor going on year 8, aprox 1,500hrs. the Spark plugs always look like they are running clean, so I don't worry about it, change the Oil once a year, or more if you like couldn't hurt.

[big foot]

Thanks guy,s , Empire thanks for that link , that explans alot , glad that it is more normal then I thought .

[fishin"G"man]

Heres a tidbit of info that may change what oil you use... Castrol is an east coast oil meaning it is high in sulfur. All oils from the east coast (like Quaker state, Castrol, Penzoil) are high in sulfur content. As you know, sulfur is an enemy in oil and why they dropped sulfur from diesel oil. It draws moisture and then as we all know water and oil don't mix so it sludges up. The fix for that is additives like detergent. But the addition of detergent in the oil also takes away the ability to "stick" to the parts. Yes, it cleans too but think of the benefit. Is clean better than stickiness to engine parts especially at start up? It would be great to have both, and you can! West coast oils are not sulfur based and therefore do not draw as much moisture and require less detergent. But they are still carbon based.

Petrol from the earth is multi module meaning it's like mixing 3" rocks with sand or pea gravel and everything in between. Lots of places for dirt to collect and carbon base oil does burn quicker too. Yes, it will lubricate but because it burns easier the black oil (carbon) you see is in part burned oil and dirt from the engine. The dirt has a greater place to hide or collect in these petroleum based oils. So what is the fix for that????

Switch to synthetic. The molecules are uniform (small) they clean better because they get into places the carbon based oils couldn't and it doesn't burn like carbon base oils and the hang time on parts is WAY better. The result is a cleaner longer lasting engine.

Look up synthetic oil on the net and see for yourself, it's a better oil all the way around.



Have a 2003 115 Merc with only 250 hrs , last year with 50 hrs on last oil change oil came out totally black with about a 1/2 qt over full with what looked like mixed with some fuel , a small amout of clear water came out first when oil was drained , this year with about 50 hrs on this oil change the oil came out again extra black , again looked like some fuel mixed in as the level was about 1/2 over full mark also with a 1/2 cup of clear water first when oil was drained , Any suggestions or advice would be appreciated , thanks ( motor does run great with the only problem that it sometimes dies when coming off full throttle ) Forgot to add I use Castrol GTX 10w40

[foxer]

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