Water in oil...or not

jcoelho

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Jun 1, 2005
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25
1997 mercruiser Alpha Gen+ 6cyl: recently took boat to marine mechanic for tune up and drive service/inspection. I've winterized my boats for 10 years, no problems. Prior to bringing the boat to mechanic, I started on muffs, checked oil, got it to operating temp - no issues. I had changed oil in Fall during winterization. When I picked the boat up, mechanic said he changed the oil, plugs, did timing, distributor, etc. I mentioned I didn't need oil changed because it was fresh oil from the Fall winterization but he said it was "milky" and needed changing. Milky? I knew milky meant water so I became concerned. I've run the boat several times on muffs and in water since - no evidence of water - no milky oil on dipstick, no rise in oil level. Engine runs great. The only issue I see is when I take the oil cap off, there is condensation/water drops on the cap after running the engine. I suspect this is normal. Mechanic suspects water intrusion was from water entering the carb over the winter - I left the flame arrester cover off over the winter...but it was shrink wrapped...I suspect if there actually was water in the oil it was from condensation. Bottom line: are water drops on oil cap normal after running?
 

dubs283

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Jul 27, 2005
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Re: Water in oil...or not

are water drops on oil cap normal after running?

i would say that the water you are seeing is from condensation - try taking the boat for a few hard runs, get the motor good n warm let it sit for a bit do another hard run, etc... then check the oil, you will know if you are "making" oil

did you vent the shrinkwrap??
 

jcoelho

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Jun 1, 2005
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Re: Water in oil...or not

yes, I suspect condensation. I did vent the shrinkwrap. I also changed the thermostat during winterization. It does now appear to take longer to warm up, but does eventually get to operating temp as before...just seems to take longer. I doesn't seem to be stuck open; just takes longer to warm-up. I'll take it out for a few good long hard runs, and check it out. It is still a bit cold here in NY - water in hudson is COLD, so this may be the issue...yes? Otherwise, running great - except it still diesels/run-on. Is it good practice to turn off engine while in gear to help prevent run-on? this seems to work.
 

dubs283

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Re: Water in oil...or not

let the engine idle for a bit before shutting it off, this will help prevent dieseling

shutting it off while in gear probably won't help much

did the mechanic perform a FULL tune up or just plugs and cap??
 

jcoelho

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Jun 1, 2005
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Re: Water in oil...or not

plugs, cap, timing, carb cleaning, ...what else is included in a full tune up? Thanks.
 

dubs283

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5,332
Re: Water in oil...or not

what else is included in a full tune up

plugs, cap, rotor, wires, fuel filters, set timing/idle, clean flame arrestor, spray carb choke/linkage, if it is a t-bolt igntion a new style sensor if it hasn't been updated, conventional igniton would get new points and condensor and set dwell, lake test
 
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