Milky Oil From Generator

[tig1]

My buddy has a Generator repair business. Generac Gaurdian. Yesterday he did a PM on a 2 cyl generac, and when he changed the oil(FF) it came out very milky. I saw the oil today and can verify what he said. Since this is an air cooled engine, I can only think it must be from condensation.
Any other ideas. He put Mobil 1 5w30 in and plans to check it in a month. These engines do run 10-15 minutes every week.

 

[Colt45ws]

10-15 minutes idling?

 

[bluestream]

My guess would be moisture in the oil from running enough to burn off condensation

 

[Steve S]

Condensation. Excercise the engines longer and see what happens. What load is the engine/Generator run at.

 

[gd9704]

Perhaps 10-15 minutes a week isn't enough to burn off the condensate that builds up?

 

[tig1]

It's the standard run time for these generators. He said he has never seen this before. When he goes back if there is any more milky oil he will increse the run time and have it run on both cylinders.

 

[Best F100]

Resulting with that milky oil is normal with these generators. I have owned a 13kw Generac for 5 years. I just changed my oil a couple of days ago - after having the oil in all winter.

I had enough "milky" oil come out to fill a small Dixie cup. I was using 1 qt of Mobil 1 0W30 + 1 qt of Mobil 1 MX4T 10W40 motorcyle oil. I don't think the 15 minute weekly exercise time is long enough to burn off this condensation.

This time, I decided to try something different. I put in Amsoil WCT 10W30 marine oil. It is supposed to be heavily fortified with anti rust additives and is designed for a high condesation marine engine environment. I expect to see the same milky oil, but hey - it can't hurt anything.

 

[boraticus]

It wouldn't matter what brand of engine/generator is being used if the oil temperature doesn't get above the boiling point of water. The engine oil has to achieve or surpass 212 deg. (100 deg. C) to cook off the water. Idling won't do it. The machine needs to be under load to generate enough heat. Try loading the machine and running it for half a hour or as long as necessary to get the temperature up. Use an infrared thermometer to get an accurate reading of the temperature of the block.

 

[tig1]

Originally Posted By: Best F100
Resulting with that milky oil is normal with these generators. I have owned a 13kw Generac for 5 years. I just changed my oil a couple of days ago - after having the oil in all winter.

I had enough "milky" oil come out to fill a small Dixie cup. I was using 1 qt of Mobil 1 0W30 + 1 qt of Mobil 1 MX4T 10W40 motorcyle oil. I don't think the 15 minute weekly exercise time is long enough to burn off this condensation.

This time, I decided to try something different. I put in Amsoil WCT 10W30 marine oil. It is supposed to be heavily fortified with anti rust additives and is designed for a high condesation marine engine environment. I expect to see the same milky oil, but hey - it can't hurt anything.


That's odd, because he does PMs on these all the time and has never seen this condition. As I said he may set the gen to run on both cyl. when he checks it in a month.