Diesel in my oil???

[Turd Furgeson]

Hey Guys,

I'm a long time lurker and I love the website. My father and I purchased a John Deere 770 with FEL and Backhoe a couple years back. Last year I noticed the oil level was rising and it looked a bit reddish. I ended up pulling the lift pump and found a torn diaphragm. I didn't like the idea of that happening again or the price of a new pump from the dealer so I fabricated a block off plate/mount for an electric pump. Fast forward a year or so to a few nights ago. I was clearing snow from the driveway and was just about done. I heard some metallic rubbing sounds that were coming from the front of the tractor and i thought they could have been internal to the engine. They only lasted for a few seconds and were sporadic. I drove the tractor back up the driveway and it sounded normal.

I checked the oil and it was high. Last time i changed the oil i overfilled it a bit. I remember doing it but can't remember how much. Since I'm wired a bit paranoid I was thinking that I may have a leaking injector or injection pump, I drained the oil and I had a little over 5 quarts come out with the filter. For some reason the oil seems very runny to me but it does not seem to have a diesel smell that it had the last time. Are there any tricks to seeing if there is diesel in it? Can I fill up a glass jar and wait for it to separate? I was thinking about carefully measuring 4.2 quarts out of my barrel and keeping an eye on it.

Thanks,

TF

 

[Leejohn]

My JD would do that, but not all the time. How I found out, (The hard way) that it was diesel fuel. Had at little fire going though I would just burn the old oil, well it was a BIG fire right now! The oil I took out was hot from running the tractor. The glass jar might tell you.

 

[greg_g]

Yup. The specific gravities of 15W40 engine oil (~0.89) and #2 diesel fuel (~0.81) are far enough apart that the two will separate in a jar that's left to settle overnight. That's assuming that it was well mixed when you took your sample. Given that the SG of water is 1.00, that means the oil should settle beneath the fuel. If you find 3 layers, that means you've got water in the oil pan too.

//greg//

 

[tomd999]

Hiya,

If you want to be certain, get a sample off to an oil analysis lab. Letting it settle, throwing it in a fire or smelling it aren't 100%, chemical analysis is.

Tom