All that glitters is not gold? (metallic engine oil)

[Pontisteve]

Today, I drained the oil in a 5 HP Troy-Bilt Pony rototiller. It has a Briggs & Stratton L-head engine. It does not say anywhere that the cylinder sleeve is cast iron, so I am assuming it is not.

The oil coming out looked very glittery to me. And in the bottom of the drain pan, I see somewhat larger glitter. I'm sure it's aluminum from the silver looks of it. The engine runs fine, and as far as I know, it has been decently maintained and not run low on oil that I'm aware of.

My question is, what causes the glitter? And is it a problem? Usually it is (in my mind) a big problem, but I'm wondering... do engines that do NOT have a cast iron sleeve just have a bare (aluminum) hole punched in the block? Does this hole have any coating, like Nicosil? If it's a bare aluminum bore, does that mean that you can expect to see glitter at every oil change as a normal sign of wear?

And if glitter is never supposed to be there, then what might be a likely suspect for failure?

 

[reynoldston]

Unless someone added something to the oil somewhere along in the pass future it doesn't sound good. If this is something you don't know and it is running good and not making any bad sounds I think I would rinse it out with something like mineral spirits real good and then install new oil. As long as it runs good and not making any odd noises just keep a close eye on the oil and use it. If this is something that brothers you I would say a complete tear down.

 

[Pontisteve]

I had the exact same thoughts. I drained the oil, filled the crankcase with mineral spirits and shook it around, dumped that, repeated that, and then put some fresh oil in it. I ran that or a few minutes at full throttle, and then drained that. The oil was grayish, and seemed thin, like there was definitely mineral spirits left in it, which suprised me since I had dumped it out pretty thoroughly. I ran out of oil, so left off there for the day. Tomorrow, I will add some fresh oil and see what happens.

What I'm wondering, from those who have one, is could it be just general bore wear on an aluminum block that doesn't have a cast iron sleeve?

I'm also having trouble thinking about what could be causing it. It runs good, doesn't smoke, and has been well maintained. Cranks are too hard to shed material, but perhaps the plain bearing?

 

[Grass ala Mowed]

I have a 5 hp Troy Bilt Pony (B&S 54xxx engine) I bought new in 1991 and ran the dickens out of for years (2000 sq ft garden). I've never seen what you describe. Always used sta-bil, changed the oil every 25 hours and a new plug every year. Usually started on first pull. I called Troy Bilt and asked why thier owmers manual said change the oil every 25 hours and the B&S manual said 50 hours. The customer rep told me "we sell rotatillers, not engines." Says a lot and I lamented the demise of Troy Bilt. Now just a glamorous name for MTD.

 

[reynoldston]

I had the exact same thoughts. I drained the oil, filled the crankcase with mineral spirits and shook it around, dumped that, repeated that, and then put some fresh oil in it. I ran that or a few minutes at full throttle, and then drained that. The oil was grayish, and seemed thin, like there was definitely mineral spirits left in it, which suprised me since I had dumped it out pretty thoroughly. I ran out of oil, so left off there for the day. Tomorrow, I will add some fresh oil and see what happens.

What I'm wondering, from those who have one, is could it be just general bore wear on an aluminum block that doesn't have a cast iron sleeve?

I'm also having trouble thinking about what could be causing it. It runs good, doesn't smoke, and has been well maintained. Cranks are too hard to shed material, but perhaps the plain bearing?

I have never ran across this other then a engine with internal problems, this is why I asked if someone could of put something into the oil? No on the cylinder walls, I have never seen it but I haven't seen everything. I have learned in my many years of repairs that something different is always around the corner. This is why I don't like the word no. It sounds to me like you have to make that decision keep running it till something lets go and the damage is all ready done or a rip down. If it was mine I would take it apart but also I have the time, skills, and tools for this being a retired mechanic with nothing better to do.

 

[Pontisteve]

Yeah, that's the decision I'm faced with. Im going to put some fresh oil in it, and put a little time on it, and see if the problem reappears. I don't want to rebuild this motor for nothing. I have some experience rebuilding a 16HP single piston Briggs, and all the tools and know-how, but it isn't exactly fun. At least, not as picky as I am about cleanliness.

That other Briggs had low compression and major smoking, and I did a leakdown and determined it must have had major issues. Tore it all apart before I realized that the bottom side of the head gasket had blown out, losing compression into the pushrod area. I even looked at the head gasket when I first started the rebuild, but I did not notice that it was only blown on the bottom side! Doh. Rebuild that motor for basically no reason other than a $7 head gasket. So now I'm a little gun shy about diving right into a rebuild. Especially since this 5hp runs great, and was well maintained. I just saw glitter in the oil. Or something. Whatever it is, it can't be good.

Can you think of any parts that are failing internally that would cause such glitter? Something aluminum must be going to hell. Would tore up plain crank bearings look like that?

The good news is that this motor is an L head, and appears to be much simpler in design than the OHV 16HP I rebuilt. It kind of looks pretty easy. Plus, it looks much easier to pull the motor off the machine than that Toro lawnmower was. Although I am not familiar with the L head valvetrain assembly process. (seems stupid to me, to have valves seating into the block).

 

[flyerdan]

Anytime that an engine starts making metal flakes is bad news; I'd suspect the big end rod bearing is going. Test it for slop by rotating back and forth with the piston mid-bore and listen for a slight sound from the bearing slack. Or if you can't hear anything, try pushing the piston with a dowel on the downstroke and see if you can feel a slight movement before the crank turns (assuming that you can access the piston through the spark plug hole.)

 

[reynoldston]

I agree about the cleanness, very importain part of any work you do. If you are doing a tear down do a compleate extereior cleaning before you even start. Then just clean as you go. This engine should be a very simpal engine to work on. I really don't see why you should have to do any thing with the valves other then check the adjustment seeing it runs good. Seeing I worked on trucks most of my working years this is just a fun work bench job to me.

 

[Joe79]

Wear in the crank case. Loose connector rod? 2 bolts tighten up.