1998 15HP 4-Stroke Water in engine oil after impellor change?

So I replace the impellor in my 1998 15HP 4-Stroke Merc (OG674558) this spring and, in the process of reinstalling the lower unit up into the outboard, the small round coil (spring) that is seated around the lower lip of the crankcase seal, came out with the shaft. Would this be enough to allow water into the crankcase oil? I don't get a lot of water in it and the engine oil level doesn't change at all either. This is usually the case after running it for 15-20 hours at trolling speeds. I don't get any oil sheen on the water around the outboard either. You'd think that, if anything, I'd see some oil around in the water as that seal is high out of the water and that the engine oil would likely seep out down the shaft as opposed to water pushing up through the seal into the crank case? Is there any other common place that I should look into on this particular outboard for water ingress? Thanks!

Swedefj40 said:

This is usually the case after running it for 15-20 hours at trolling speeds.

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Text book “making oil” scenario.

Motor not getting up to temp to burn off condensation in the oil.

Make sure your thermostat is operating correct. Run it hard back to the dock to get oil temps up

How did you determine that water is getting into the oil ?

dingbat said:

Text book “making oil” scenario.

Motor not getting up to temp to burn off condensation in the oil.

Make sure your thermostat is operating correct. Run it hard back to the dock to get oil temps up

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Trolling speeds for me range between 1000 to 2000 rpm, it's up to temp.

racerone said:

How did you determine that water is getting into the oil ?

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Chocolate color. This is a new development this year.

Swedefj40 said:

Chocolate color. This is a new development this year.

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Looks like a milkshake.

Mad Dog 2 said:

Looks like a milkshake.

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yup

dingbat said:

Text book “making oil” scenario.

Motor not getting up to temp to burn off condensation in the oil.

Make sure your thermostat is operating correct. Run it hard back to the dock to get oil temps up

Click to expand...

On second thought, I get what you're saying about the thermostat. I'll order a new one. Thanks for the tip!

Swedefj40 said:

the small round coil (spring) that is seated around the lower lip of the crankcase seal, came out with the shaft.

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The spring in the oil seal should be facing toward the engine, not away; maybe that engine has two seals back-to-back? Maybe someone has been in there and installed it backwards? (yes, i've seen this).
Either way, you have a known problem, fix this problem! You don't want the seal to blow out and dump all your oil.

Well 4 months later and I've finally got a chance to look into the thermostat and yes it was stuck open. We'll see if it's fixed once spring arrives and we can get out. Thanks for the help people!

Change your sparkplugs also They should look black.. If you troll a lot ? A WOT for 1 mile each day home will burn off any sludge forming on the plugs & valves.
W hen you get the new plugs. You MUST MUST check each gap of each plug. Buy a cheap Sparkplug Gapping Tool. NAPA sells a $8 excellent one. It is a shiny round disc.