Today I was tuning up our Craftsman lawn tractor, getting it ready for summer. Anyhow, I forgot that we had a new motor put on it last summer (july or so) and went to change the oil. The oil that came out didn't look dirty, but it was an opaque greyish-silver color, and it smelled like gear oil. Very interesting. Thankfully, I was draining it into an empty milk jug, so I just poured it back in the top. Does anyone have any idea what kind of oil they put in my mower? I was going to drop some Mobil 1 5w30, but that's amber/gold colored and this stuff looked like it had a bunch of anti-sieze in it. This is NOT a 2 stroke engine - it's a Briggs & Stratton 17hp something-or-other. Can I use 5w30 synthetic in it? I don't want to thrash the motor.

XXL

 

The oil in my push mower turned taht color after I left it outside while it was raining. Water enter the engine and got the oil all wet. I would think you could put any motor oil in it. Just to make sure go to Home Depot and buy some lawn mower oil it's only $1.20 a bottle!!

 

sounds like a bit of moisture to me...

I'd bet that the oil is nothing more than what you could find at any store.

I'd hesistate to put 5w30 in it though.....Personally I feel that a 15-40 would be a bit better or 30 wt as you <a href="http://www.motorhaven.com/">owners manual</a> may say..

It's not like its going to be 40 below out when you mow your lawn....least I hope not.

 

If its milky looking its probaly moisture, silver colored like anti seize is aluminum metal wear from rods, piston, cylinder, etc. (another bad engine)
Briggs calls for 5w30 syn. or #30 conv. for the oil.

 

Matt, the way you described the oil you drained out, sounds exactly like the oil I drained out of my new Craftsman lawn tractor after 25 hours of operation. I believe it's a break-in oil installed by Briggs & Stratton. All subsequent oil changes have been good as gold.

BTW, there was a poll I started not too long ago for mult-grade vs single grade oil for yard equipment. You should check it out.

Scott

 

Thanks for the recommendations, guys!

I'm thinking about going with superrangerman's suggestion of using 15w40 for the summer months. On the flipside, I've got a snowplow attachment for it, which brings me to another question - can I use M1 syn 0w30 in the winter? I figure it would make it super easy to start when it's cold out.

The oil looked like it had anti-sieze mixed in with it, but I did the smear test (smear a bit on the back of your hand) and I didn't see any actual particles - the oil was just grayish. I'm thinking Scott was right about the break-in period.

Scott - I'll skate over to the thread you mentioned. I think I may have popped in a while back and dropped a nugget of wisdom. Either way, should be informative.

XXL

 

How about a good 10w30 dino for the winter months?

I guess I feel that putting synthetic in a mower is pointless IMO, not that I'm saying it would'nt work..

I guess i feel that you'd never get your money out of it compared to a good dino on a lawn mower.

 

Good point, but I figure "the engine holds 1 quart. I think I can spend a little extra". I use Dino in my Expedition, but I figure for a lawn tractor, I might as well kick out a little bit extra and get the synthetic. It's not like I'm going to think during the 2x a year oil change "damn....shouldn't have spent all that money on this synthetic...."

XXL

 

Perhaps your engine is cast iron? I have couple tractors that stay out in the cold garage all winter. The oil turns to almost a milky grey color. Its from the heating up and cooling down of the block. It's perfectly normal. Just make sure youchange the oil at the begining of every season.

 

I think the B&S oil was straight 30 - I put the Mobil 1 5w30 back in, and the engine sounded kinda "thrashy" until it heated up, then it purred like a kitten.

It's still got some of the silvery stuff in there...I'll wait until I've mowed the lawn a few times and then I change the oil again. I'm planning on dropping 0w30 into the tractor/snowplow and the snowblower this winter - it should take care of my cold-start problems.

XXL