How fast/long can I safely run my engine out of gear in the slip?

[Goodman98155]

I have a 1996 Mercruiser 5.7 with an Alpha One gen 2 outdrive. I am hoping that the bit of milkyness I see under my oil fill caps is due to condensation over the winter and not something much worse.

To burn this off, I read here that the engine needs to be run up to operating temp for a period of time. I'm not currently able to take the boat out and run it normally.

Am I doing any damage to the outdrive by running the engine at say 3000 rpm for 20 minutes or so while in the slip?

I think I was bad over the winter by starting the engine weekly, letting it get up to 175 on the guage and then shutting it down. I am learning now that this could have built up a lot of condensation.

 

[Bt Doctur]

your not helping the condensation idling in a slip. you need to get to operating temp for like 1 hour or so to bake off any condensation out of the oil

 

[Goodman98155]

your not helping the condensation idling in a slip. you need to get to operating temp for like 1 hour or so to bake off any condensation out of the oil

So is this safe to do out of gear and at what RPM? Am I wearing whatever linkages go to the outdrive in an unintended way?

 

[Bt Doctur]

Nope, under load. 3k in neutral will not get it hot enough . Go out run it UNDER LOAD for atleast an hour

 

[Rick Stephens]

As stated, you're going to have to run it across the water. You should not run the motor up out of gear. Not good for the motor. Does nothing much to the outdrive except spins without turning prop shaft and without load it just sits there and vibrates. Won't accomplish much as far as temperature except adding wear.

 

[GA_Boater]

I think I was bad over the winter by starting the engine weekly, letting it get up to 175 on the guage and then shutting it down. I am learning now that this could have built up a lot of condensation.

Think about this; Your new plan is the same as the old plan except at higher RPM. Most likely the results will be the same, condensation.

All knowledgeable car people always say short trips are harder on the motor than freeway driving. You're in the short trip category until you begin to use your boat the way it was intended.

After a winter of weekly engine starts, it would be a good idea to do an oil and filter change before your season starts. Good luck and go boating.

 

[Scott Danforth]

running in a slip without a load will make more condensation.

to get heat into the oil, you need to get the motor under load.

 

[tpenfield]

how 'bout changing the oil, then run the engine at idle for 30 minutes to see if you are still getting the milkshake. . .

 

[Goodman98155]

Wound up being able to get out and run WOT on Saturday for about 15 minutes. The steam coming out of the breather tubes was like a tea kettle! Idling at the slip, I did see some light steam from the oil fill caps if I left them open but that was about it. It seems like if I let it idle for many hours, it might actually work the moisture out, but a waste of gas and engine hours.

For the record, it turns out that the starboard manifold and/or riser was letting raw water in. Water was visible in the bottom of the manifold and the plug in piston 8 was rusty. Changed all riser and manifolds out for new. After two oil changes and the WOT mentioned above, the milkiness is gone.

Thanks everyone for the advice.