Ray O wrote: >"Tercel Owner" wrote: >>Ray O wrote: >>>"Tercel Owner" wrote: >>>>I...find black sludge at the bottom few millimeters of the >>>>dipstick, while all the rest of the oil is clear. Never saw that >>>>combination before. I am told that there was no sludge at the >>>>bottom of the oil pan. >>> >>>If you see black sludge on the bottom of the dipstick, then there is >>>sludge at the bottom of the oil pan or the oil was not thoroughly >>>drained the last time it was changed. Actual semi-solid sludge than >>>you can wipe off the dipstick is a bad sign. I would run some >>>engine flush through, change the oil, repeat the process, then drop >>>the pan and thoroughly clean it, or if you can't get the baffles >>>clean, replace it. On the other hand, a little discoloration or >>>stain on the metal dipstick is not anything to worry about. >> >>It is quite wipable, and quite distinct from the almost transparent >>new oil. But my mechanic said he checked for sludge on the bottom and >>found none. > > A dipstick will naturally get darker with age, almost like a stain. > I wouldn't worry to much about that.
Just to clarify, it's not actually the dipstick that is darkening, it is residue on the bottom of the dipstick, which can be wiped away. It occured to me that it could be just crud on the walls of the "scabbard" in which the dipstick rests. Maybe from having the engine sit on the shelf for too long. I assume that used engines sit on the shelf without oil in them, so this black stuff might be dried out oil residue. I'll see if it depends on how I pull the dipstick out tomorrow (in daylight).
I said it was wipable, I'll take a closer look in daylight. It may actually be thicker, but it might seem very fluid because there is so little of it. If it was dried out oil residue on the interior walls of the dipstick "scabbard", then I expect it to be more sludgy (just instinct, not sure if that would correpsond to reality).
It is possible, but he didn't say anything about an additive. I took a whiff of the oil and it smells a bit like gasoline. Maybe that's normal. I'll purchase some fresh oil to compare smells. If the engine doesn't burn oil, I'll probably end up discarding the bought oil without using it; some googling as shown me that oil should not be kept or used if you can't remember when you opened the container.
Even if he added stuff, though, it is odd that it would float around the 1quart depth beneath the surface of the oil in the pan, and be crud-black. For the moment, I'm inclined to suspect crud on the interior of the dipstick scabbard.
Yes, I heard that removing the crud can cause problems, and my mechanic agrees. Seals may start leaking, and crud removed from the inside rim of the piston rings (where they seat themselves in the grooves) may cause them not to scrap the cylinder walls as well -- especially if the rings are cracked. This is besides the possibility that crud comes off in large quantities and plug up some oil channels.
I may try that yet, just not confident enough to do that right away. And having a place to do it is a bit of a problem. I'm even scratching my head to think of a place where I can put the car up on jack stands without raising eyebrows, preferrably without much traffic (don't want the car bumped with me under it).
From your comment about front & rear seals drying out, I assume that either they empty out the oil prior to boneyarding it, or the oil level in the pan doesn't come as far up as the front & rear seals. Emptying it out seems to make more sense to me.
Having driven the car around for a few days with this 2nd used engine, I'm finding tremendous oil smells entering the cabin, much more so than the 1st one. The strange thing is that I don't recall such strong oil smell on the day of picking up the car, but it seems to get stronger day by day. Now just opening the door and getting into the car is like walking into a wall of oil fumes. There is no black/blue/white smoke upon startup. Thus the desire to put it up on jack stands to poke around underneath.
There was only a bit of coolant in the overflow reservoir (which I topped off today), so it's hard to tell if there are bubbles or traces of oil in the coolant. Doesn't seem to be from looking under the radiator cap, but it's not as discernible there as in the reservoir. Check again in daylight tomorrow, after driving around a bit.
The oil level seems steady at 130% (where 0%=low-mark,
100%=high-mark), but it's not easy to tell because of the unclear way in which the oil level shows up at that level. Normally, the oil on the dipstick has a nice, clear edge, almost like the edge of a bead of water. However, at the 130% region, the oil film thickness tapers off for the last quarter inch and leaves very confidence on the accuracy of the oil level.