Let's have a wear pool on my jeep

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Sep 28, 2002
Okay, everyone knows that I like to buck convention. If you say that 5 is too many ...I'll pile on 83 just to make sure that I've covered all the bases in variance in an attempt to find out the truth. The results aren't always all that enlightening ..at least beyond "what didn't happen" (the earth didn't stop rotating, atmospheric conditions stayed the same, the fed didn't alter interest rates, etc.) eyesgotz2nose. In that spirit, I've just drawn a sample from my wife's 4.0 TJ that is 2000 miles into a rinse phase of a one shot Auto-Rx cleaning with MC 5w-20. This is just to verify that nothing too radical is going on ..but is also to check on air filtration before I do an "in engine" VOA (a couple of heating cycles) and a 5k run on MC 5w-20 (the oil is in there now ..and will be for the next tests). I've been using a cylindrical K&N filter that I typically serviced biannually. Most commented that I was servicing it too often, so I let it go. My Si and Na numbers were pretty good ..but I wanted to see if leaving it unserviced longer was the right thing to do. So, what do you think this will show? I have a high volume oil pump and this is the only visc that has managed to actually "fit" into the engine after startup. 30 and 40 weights are up against the relief off idle (58lb) even when fully warm. Now I'm at 51+/- on the highway ..and anywhere between 22 and 32 at idle. I expect: extremely low Pb (if any) elevated Fe (how much, I don't know [Confused] ) and other elements based on how good the air filtration was. What's your guess? The best UOA ever? Pending doom for the valve train? Mediocre results with enough stuff to nitpick to keep everyone busy for a day or two ..maybe a two page topic? Place your bets. The contestant with the most accurate guessimate will be awarded the highly covetted Gary Allan [HAIL 2 U!] for being a true prognosticator of distinction (that and $2+ will get you a cup of coffee at Starbucks). Barbra Streisand will sing for you. [Big Grin]
No ..no change in sound whatsoever. No apparent differences except some placebo effect of being more "free revving" (hint: I don't think they ever made a 4.0 that was "free revving").
What? NO destroyed bearings? Only 44ppm? I like your way of thinking [Big Grin] Where are my thicker is better pals?? Remember, before the Auto-Rx w/MC 5w-20 this engine has had about 50k of nothing by HDEO 5w-40. From the real deal D1 and the imposter T&SUV ..to RTS.
Originally posted by Gary Allan: What? NO destroyed bearings? Only 44ppm? I like your way of thinking [Big Grin]
Well I know that the 2.5 and 4.0 throw iron. I think the specs are around 32ppm if I remember corectly. So puttin in the thin oil should raise the iron up some.
I'd say that wear will read really low...oil that thin won't even carry the wear metals around the engine, let alone into the sample bottle.
Originally posted by Shannow: I'd say that wear will read really low...oil that thin won't even carry the wear metals around the engine, let alone into the sample bottle.
Much to my disappointment, I don't see a trend of UOAs showing any relation between viscosity and wear metals. In fact, a trend I do see with much sadness is SM dino oils with pathetic looking additive levels putting out really low wear metal readings...suspiciously low. Almost to the point of: the better the oil, the worse the UOA wear metal levels. So I think UOAs are great for telling how much longer the oil can be run (TBN, TAN) and whether there are dirt ingestion, coolant into oil leakages, or fuel dilution problems. So if I made a prediction for you it would be nothing but meaningless numbers to me! Now if you had a magnet inside or outside of your oil filter that you could monitor what it picks up, that would be really cool. I do it: one inside (can't remember the brand since I reuse the same one) and one outside (FilterMag).
You make excellent points. There is an elemental profile to this engine and all that I'm looking for is radical valve train wear. That will usually stick out well above the background noise. How much that spike extends, if it even occurs, is the question here.
Don't worry, Shannow, I'll use coal tar as a flushing agent when the testing is done [Wink]
Originally posted by farrarfan1: Marco!
[LOL!] We went to a tree farm to get a Christmas tree one year. They said, "Just yell out when you find one you want". You were surrounded by trees and couldn't see but a few feet. My wife yelled out something..then my daughter yelled out "Marco!" ...from everywhere within an acre and a half you could hear "Polo!". The tree cutter guy didn't know what to do. [Big Grin]
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