Grey colored motor oil

[nbpt100]

I am helping a friend with his air cooled 17.5 hp lawn tractor. He had a number of issues. I resolved all of the small issues but noticed the oil was grey in color. I have never seen that. Someone said it was water. Another said it was from metal particles from a part wearing out. Either way I think it needs to be changed and flushed out. I am not sure exactly what is going on on the inside with out taking it out of the machine and opening it up. Not sure how that much water would get inside of the crank case. Even if the air is humid, I would think it woud take a lot of water to make it grey. It was stored outside under a tarp for the winter. But it has been for 12 years and never had this problem.

Thoughts?

 

[The Cobbler]

if it is metallic looking, a rainbowy look , It's probably metal.
not sure how water would get in there , but I've seen an air compressor that was left outside uncovered with grey oil from water entering

 

[Leaflessshadetree]

Changes in air temperature and not running long enough to get warmed up will collect more water than most would believe.
Metal shavings will feel gritty.
Either way changing the oil is needed.

 

[gunguy]

Pick up an oil analysis kit, capture a sample while changing the oil, and send it off. My guess is condensation.

Jim

 

[jack stand]

Little gas engines are only a quart (or 2). Change the oil then watch it.

 

[nbpt100]

thanks for all of the replys. I am thinking of doing 2 oil changes to help flush out what ever is in there. It is hard to get all of the oil out. It has been running SAE 30. I may put in 10w-30 and run for an hour or so. Observe if the engine smokes much or at all, and look at its color and feel for grittiness.
If it smokes while running I may opt for Vanguard synthetic 15w-50. Otherwise I am thinking I will stick with the SAE 30.

This is Briggs and Stratton's latest oil viscosity charts for mowers.

 

[Von Psycho]

I would drain the oil then put some varsal in the sump and shake the mower side to side and drain.
Add your oil, run and change your oil again.
Like Leaflessshadetree said get your engine hot to avoid condensation.

 

[dcg9381]

Gray generally means water to me, which doesn't make much sense with an air-cooled engine, unless it sat outside.
Metal will show up as a sheen... If you've got enough metal to discolor something, that motor is in big trouble.

 

[tdkkart]

thanks for all of the replys. I am thinking of doing 2 oil changes to help flush out what ever is in there. It is hard to get all of the oil out. It has been running SAE 30. I may put in 10w-30 and run for an hour or so. Observe if the engine smokes much or at all, and look at its color and feel for grittiness.
If it smokes while running I may opt for Vanguard synthetic 15w-50. Otherwise I am thinking I will stick with the SAE 30.

This is Briggs and Stratton's latest oil viscosity charts for mowers.

If it's making silver colored oil you may be lucky if it runs long enough for 2 oil changes.
BTW, you can buy Mobil1 15w-50 synthetic for 1/2 the price of the vanguard and I'd bet $100 its the same thing.

 

[BillK]

But it has been for 12 years and never had this problem.

Thoughts?

How do you know that ? Have you looked at it before ? I bet it has been like that for a long time and it is strictly moisture from being outside under the tarp.

 

[PWC Repair]

Has he already admitted that he has NEVER changed the oil? LOL! But ya, if it seems to run Ok then drain it, put in a qt of diesel fuel and shake the thing back and forth a bunch, then drain it out. Put in new oil and run it to see what happens.

 

[Crazyjake8493]

The only time I've come across gray oil was a used snowblower I picked up for free. It had sat out for a year or two and got water in the oil. Drained the oil, flushed some new oil through, filled it up and ran it. Snowblowed a few times then changed the oil again. Still using it a few years later and the oil looks great now.

 

[nadogail]

Engines collect condensation, that is why they need to be exercised, rather than just started, from time to time.

 

[nbpt100]

How do you know that ? Have you looked at it before ? I bet it has been like that for a long time and it is strictly moisture from being outside under the tarp.

You assumed wrong Bill and would have lost your money. I worked on it last year and the previous year. The owner even flagged the oil color to me this past week as unusual. He knows how to check the oil and add as needed. He even usually changes it himself. He has the awareness you assumed he does not. Maybe most people would not have that awareness. He does. He notices details.

 

[BillK]

You assumed wrong Bill and would have lost your money. I worked on it last year and the previous year. The owner even flagged the oil color to me this past week as unusual. He knows how to check the oil and add as needed. He even usually changes it himself. He has the awareness you assumed he does not. Maybe most people would not have that awareness. He does. He notices details.

If that is the case then the only correct way to find out is to take a sample and send it off to be analyzed. Anything else is sheer speculation.

 

[nbpt100]

Just wanted to follow up. My friend has reported to me that the lawn tractor has been running well. He has mowed 3x so far so it has about 2 hrs on it. I told him to closely monitor the oil and he says so far it looks a normal color. So it sounds very likly it was water in the oil.