Inspecting waste oil

[betsy325e]

Dear Thirtians,

Did an oil change this morning, ran the waste oil through a fine painter's strainer with a magnet in the bottom.

Nothing shiny, but a few...maybe 10 super tiny chunks of some hard stuff that wasn't adhering to the magnet. Almost looked like rust flakes, really dark brown. Definitely nothing shiny. I did just do a valve adjustment outside (trees sort of hang over the driveway), so I don't know if its nature schmutz or.... this engine has never been rebuilt, so I'm curious if this could be bronze from the bearings (not sure of the composition of stock bearings on an m20b27). Is this something I should be worried about?

Also, this car is my daily and it basically never sees the highway (had a close call with overheating with a bad fan clutch and broken aux fan -- constant construction for the last few years on the highways around me). I did notice just the tiniest bit of "coffee" on the top of the oil after letting it drain the last few drops over the course of an hour. I'd say maybe an ounce if I had to guess. Do you guys think this is normal for never really running the car for more than 10 minutes at a time, or is my head gasket going?

Gonna cut open the filter after work.


Thanks,

J

[jlevie]

The small particles don't worry me all that much as the filter will catch them. If the bearings, which are lined with a Babbit like material, were going, the oil will have a shiny metallic look to it.

The "milkshake" on the oil might, or might not be something to be concerned about. Since you apparently don't drive on the highway, it could be nothing more than combustion blowby condensates. Worst case, it could be a leaking head gasket.

The nicest thing you can do for the engine is to take it out for 20 minute highway speed once or twice a week (30 minutes in colder weather). It takes that long to get all of the engine up to the temperatures need to boil off the condensates. Also decrease your oil/filter change interval to 2500-3000 miles.

Then see what the oil looks like at the next change. I suspect that you won't see the "milkshake" in the oil.

[betsy325e]

Thanks!