5.7 OMC engine oil looks "rust colored"

[Bo Russell]

Hi, New omc owner..just bought boat 89 5.7 raw water cooled, all water was drained before I picked up. got ready to winterize and noticed oil is really clean but looks rust colored...any ideas? Had i/o"s before never seen this...not milky, no gummies in filler caps, engine sounds good, ran w/o muffs for a two minute guzzle down carb with mystery oil before parking for winter as i will replace impeller in spring, filled hoses and all with anti and see from there. just was taken by the oil color.

 

[Don S]

Re: 5.7 OMC engine oil looks "rust colored"

ran w/o muffs for a two minute guzzle down carb with mystery oil before parking for winter as i will replace impeller in spring,

Plan on a new pump housing as well. After 2 minutes, that plastic housing is melted. I wolud imagine the insides of the rubber exhaust hoses are fairly charred as well. Will probably blow during the summer.
Not a good thing to do, 10 to 15 seconds at idle is one thing, but not 2 minutes.

 

[180shabah]

Re: 5.7 OMC engine oil looks "rust colored"

OT - Don I love the new title for the sticky...

 

[Bo Russell]

Re: 5.7 OMC engine oil looks "rust colored"

OK my bad, So any clues as to the color of the oil? Real time run was no more than enough time to pour a half pint of MMO down the carb, And I always change out impellers every spring even on the outboards I have owned....prevention the best medicine.
I was hoping to get a go to place to check on this oil color thing. Long winter here in NH. Figured I could have a small project on my hands to keep me busy. So anybody has any clues as to weather or not this is a concern or just a fluke it would be appreciated.


Thanks,
Bob

 

[Bondo]

Re: 5.7 OMC engine oil looks "rust colored"

So any clues as to the color of the oil?

Ayuh,.... Purely Speculation,...

When sitting for a long time, in varying Temps,...
The cast surfaces inside the oil cavities will tend to surface rust from condensation....
I'm speaking of the rough cast surfaces,... Not the machined working surfaces of the block...
Your short run, might have washed this rust into the oil.....
Maybe....

Good Luck,+ Welcome Aboard...

 

[mkast]

Re: 5.7 OMC engine oil looks "rust colored"

Not knowing the history of the engine, change the oil and filter.
Warm the engine up, look at the oil.

 

[180shabah]

Re: 5.7 OMC engine oil looks "rust colored"

Ditto - Change it, run it, and see what you get.

 

[Bo Russell]

Re: 5.7 OMC engine oil looks "rust colored"

Hi Guys, Spring sprung and I finally uncovered my boat, cleaned, checked and changed oil. ran it for ten or some minutes...yes with muffs this time and all is well. Thanks for all the great ideas and help..can't wait to get on the water!

Thanks,
Bob