Boiling Oil ?

[jpackard56]

O.K. it was over 92 here today and I had been mowing for about 2 hours. Before parking in the barn I decided to do the oil change. After getting over the shock of the plastic "gizmo" drain plug, I was shocked a second time because the oil came out boiling and bubbling into the drain pan. What in the world? This is a GT2544 with 22hp Kohler command, 25 hour service interval. Any thoughts???

[SWilliams]

Air cooled engines run HOT to begin with, Then consider that most newer models are set up to run very lean to keep emissions down and that the crappy gas available these days makes that even worse because the alcohol runs even leaner and you get a LOT of heat built up. Since they also use the oil to keep the engine cooler all that heat really piles up. What you saw is the result.

That's why I do a few things to help the engine out : I blow out the engine shrouds after every use so that grass and crud don't collect and block airflow. I run nothing lower than 91 octane and if I can find it non ethanol gas. Plus FULL synthetic oil in the engine to help with oil break down due to heat. (I run either Mobil -1 or Amsoil depending on the engine.)

I also am looking at adding some vents at the side panels like some of the supers had to allow more of the hot air out. Consider that the 22 horse in my tractor currently runs hot enough that it caused the grill to sag!

[mrbrown]

I agree with the use of syn oil in a mower. I ran mobile 1 in a mag 18 in a craftsman and could feel the difference in temp after mowing. Mike

[vince_o]

Im not sold 100% on the synthetic oil in the mowers, but I will say that if your using just regular 10-30 from the parts house, your oil is getting too hot. The oil made for air cooled engs has a lot of zink in it to help cool it.

Oh and Im a ford guy, just incase its brought up,

[jpackard56]

Oh and Im a ford guy, just incase its brought up,

Is that a bad thing? If so I'm in trouble cause I was a truck fleet mechanic for them in my checkered past. Now I'll drive anything I can afford, translation CHEAP !! But we still have some Fords...My 2000 F-250 4wd Power Stroke (59137 miles) is in my barn getting a transplant this summer, the neighbor drove it into a wash during a flash flood pulling a fifth wheel with a donkey that the whole area was glad he had sold and needed to deliver, but alas even 7.3's don't tolerate that well

[BigMike]

Are you sure it was boiling and not just areated?
Even with a pressurized oiling system there is still a lot of oil flinging and flying all over in there and I would be very surprised to drain the oil from a hot motor and NOT see some froth.

[mgonitzke]

I think BM is right and you're overreacting. I did a little googling and found an MSDS for a particular brand of motor oil that states that the boiling point is greater than 599 degrees F. If the oil got that hot, your engine would have seized or blown up, and the oil would have melted right through the plastic quick-drain.

[jpackard56]

Thanks for the feedback guys...
I really don't know how hot this oil was. I'm borrowing my brothers in-fared temp gun over the 4th.
I do know that when the oil hit the grass clippings etc. when the yellow "gizmo" shot off it sounded like frying chicken and was all bubbling and boiling in appearance.
Plan on checking temp with out the cooler I've ordered and then again after install.

[ghennessy]

You could have very well seen water boiling out of the oil. Think deep-frying. Any oil over 212 F (100 C) will boil out the water diluting it. Relates to city driving and engines never fully warming up versus steady load turnpike cruising getting the oil up to a good operating temperature and evaporating contaminants such as water and gasoline compounds. Oil does not have to be over water boiling temperature to provide enough latent heat content to drive off the water. Call it accelerated evaporation.


Oil temps over 180 degrees F are quite normal in passenger cars.