German Castrol Classic on the Blotter

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Apr 5, 2004
Pensacola & Vero Beach FL
By "classic," of course, I mean green. [Wink] . Anyway, both because I've been meaning to try it, and because the question has come up in a GC thread in the UOA section, I decided to try a blotter examination. The oil is GC, of course, it's been in my VQ35 for almost 3,500 miles over (just under a month). The car has 48.5k miles on it right now. The first two pictures are drops of of the used GCC, straight off the dipstick. A large one and a small. The last two are of a big slosh of virgin GCC from the bottle I keep in the trunk (it was windy and dark when I did this...). On the last, I used some photo enhancement to try to show that there is a slight "ringing" even with the virgin oil. Although the oil has somewhat darkened on the dipstick, this stuff looks pretty clean compared to some blotter shots I've seen. There is absolutely no metal debris visible to the eye, even with light magnification (my reading glasses...). Don't worry, I'm still going to do UOA when the time comes. [Cheers!]  -  -  -  -
My dipstick doesn't allow me to do as big of a blot - from what it looks like. I do get the "ring" effect if I keep the paper on a level surface. My car's "blots" look just like yours but with one or two little dots of reflective metal. It is like taking a really sharp pencil and putting a dot on the paper. When I get home tonight I'll upload the pictures of my "blots" and my parent's car "blots."
I wonder if the blotter paper is separating the PAO from the esters? If so, this paper holds promise as preliminary/non-conclusive detector of esters. A potential problem is that we can't automatically rule out the possibility that mineral oil would separate from PAO as well...both mineral oil and esters may have more affinity for paper than PAO. If you have some virgin Gold GC, it would be interesting to see if it forms an outer ring as well.
Notice that the outer ring is approximately the same size regardless of the amount of oil or distance traveled. My guess is that you are seeing the differnce in saturated paper on the first part where oil is on the cellulose fibers as well as between the fibers. On the second part, the "ring", you are likely seeing cellulase fibers that are coated, but air is between them.
I took a "blot" of "M02" GC green in my '00 VW GTI 1.8T, back on 6/29/05. The car had roughly 55k miles on it at the time of the sample "blot". This oil had 7000 miles on it, & the oil was allowed to "set" on the card for 12 hours or so before I took the pic.  -
My oil "blot" above didn't have any metallic specs. It shouldn't have; My UOA's show very, very minute wear metals. I doubt that they would be visible to the naked eye.
Guys, thanks for the comments. I should have added that I took the photos at about 11 hours after I put the oil on the cards. On the small blot card, when held up to a 100w bulb, you can see a very faint but distinct ring at the "leading edge" of the inner dark spot. Larger used oil spot -- inconclusive. To hazy to try to photograph. Gmorg, I've read previously that the rings have something to insolubles in the oil can't spread out as the "pure" liquid oil can. I'm going to do some more homework on this, and will report back.
Yeah, I'm obviously very curious about what is separating as the oil spreads through the paper. I had thought that various forms of contamination caused the "rings," but obviously, there's some light ringing, even in the virgin oil. I'm a complete novice regarding blotter examination, so I really don't have an explanation. I'll be sniffing around myself in spare time, and will put up what I find, if anything. BTW, I have no GCG, but might be persuaded to pick up a quart for comparison. To be very careful, my lack of gold should not be seen as condemnation, I too am starting to see the GCG light, I just don't need any for at least a couple years -- It'll take that long to use up my green. Thanks for the responses. [Cheers!]
ekpolk, you are right about the insoluables staying in the first contact zone. However, I don't think that these photos show any insoluables. I have been running thin layer chromatography since 1989. I am fairly confident that these photographs show the zone where air is between the cellulose fibers. If you discover otherwise, please let us know.
You may want to look at the link below. The insoluables are easy to see. If you look very close and use a little imagination you can see the same air-containing ring on the upper left blot. So, the upper left blot of in the link shows the insoluables, the oil saturated paper without the insoulable, and finally a ring of oil-coated fibers with air space between the fibers. However, the outer ring is difficult to see.;f=42;t=003458
GMorg: Thanks very much for the info. I'll do some more investigating and see what I dig up. Very interesting to see how much darker the ring is in TallPaul's blotters. That oil has about 1k fewer miles than mine, but my engine is much younger than his (48k miles vs 129k). Different oil too. I also should have added that I'm using LC in my GC. Any thoughts on the differences?
ekpolk, If LC works by dissolving varnish, sludge, and coking, then I would expect fewer insoluables in LC treated oil. If LC works by keeping the above nasties in suspension, then I would expect more insoluables in LC treated oil. The exception would be if LC kept nasties in suspension, but also allowed for aggregation and better filtration. In that case, I would expect few insoluables to be found in the oil (since they would be in the filter. Since I know that I don't know how LC works, I cannot predict which of the above is most likely.
ekpolk, Many BITOGers have stated that LC20 prevents oxidation. If that is the case, then I would expect less insoluables to be formed and therefore less insoluables in LC20 treated oil. However, I found an LC20/FP60 description at O2asis LLP. Most of the info listed in the "technical stuff" section describes the active incredient as a solvent. The jug clearly makes anti-oxidant claims.
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