the3rsss Posted November 29, 2011 Share Posted November 29, 2011 I have a 99 obw with 140k. I read all the threads about piston slap . ( I have a mild case of slap). But this is the first car. I have owned that slapped and I just had a hard time believing that knock was benign. So for my own piece of mind, I sent an oil sample to blackstone labs. Well, all the metal numbers were well below averages. The only thing that was off was the viscosity. I use mobil 5000 5w30 and it tested closer to 50w20p. So, you guys are right! That knock is doing no harm at all. But the test was cheap piece of mind. Link to comment Share on other sites More sharing options...
the3rsss Posted November 29, 2011 Author Share Posted November 29, 2011 5w 20 not 50w20 Link to comment Share on other sites More sharing options...
carfreak85 Posted November 30, 2011 Share Posted November 30, 2011 I have a feeling that almost nobody on this board has run a UOA, or at least those few have not posted about it in a LONG time. Thanks for sharing! Could you link to the chart for us? Do you plan on doing another sample in the future? Link to comment Share on other sites More sharing options...
porcupine73 Posted November 30, 2011 Share Posted November 30, 2011 Sounds good. Some oil blenders like to aim for the low end of the viscosity range for a grade for better fuel economy, since that is heavily related to the HT/HS (a lower HT/HS having better fuel economy) it may shear back after running it for a while. Link to comment Share on other sites More sharing options...
Fairtax4me Posted November 30, 2011 Share Posted November 30, 2011 I had an oil analysis done a few months back to the engine in my wagon to check for bearing metals. I should probably do another one now on the "new" engine. Definitely good for Peace of mind to know the internals aren't shredding themselves. Link to comment Share on other sites More sharing options...
Quidam Posted November 30, 2011 Share Posted November 30, 2011 I have a 99 obw with 140k. I read all the threads about piston slap . ( I have a mild case of slap). But this is the first car. I have owned that slapped and I just had a hard time believing that knock was benign. So for my own piece of mind, I sent an oil sample to blackstone labs. Well, all the metal numbers were well below averages. The only thing that was off was the viscosity. I use mobil 5000 5w30 and it tested closer to 50w20p. So, you guys are right! That knock is doing no harm at all. But the test was cheap piece of mind. I know it's been said that piston slap is "rather benign", but it's not like it's a "desirable" thing. It's not and the pistons are getting hammered with the cylinder walls when it happens. It's the same on this board with people saying hydraulic lash adjuster noise is "rather benign". It's not either, as you can have about .040" clearance in the valve train and the cam lobes being softer than what they are rubbing against, get hammered and beaten badly. I just tore down one of those "tick of death" engines. The cam is worn beyond specs. and you can see exactly where it gets hammered. I do have an engine with mild piston slap on start up. I just let it warm up untill it dissapears. hth Doug Link to comment Share on other sites More sharing options...
the3rsss Posted November 30, 2011 Author Share Posted November 30, 2011 Attached is a copy of the report. I had done some major engine work (HG, timing etc) over the summer and before it had gotten colder out I had never heard a slap from this engine (60+ seems to be the magic number). The only concern I have is the viscosity. I intentionally used four qts of 5-30 then topped it off with a little more then a qt of 10-30. I wanted it a little bit thicker oil at start up ,but didnt want to risk a full 10-30 oil change in winter. And I ended up with something closer to 5-20? Link to comment Share on other sites More sharing options...
porcupine73 Posted November 30, 2011 Share Posted November 30, 2011 (edited) The image is a little too small/low res to be able to read the numbers. I had a couple oil analysis done but that was back around '05/'06: http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Main=17929&Number=251148#Post251148 Edited November 30, 2011 by porcupine73 Link to comment Share on other sites More sharing options...
the3rsss Posted November 30, 2011 Author Share Posted November 30, 2011 Its easier for me to type the results then to try and get that &*$%$#@# scanner to work.... Comments. Thanks for the note about possible piston slap. Wear metals are very low in this sample, so if there is something going on, it doesnt apperar to be hurting anything. Universal averages show typical wear levels for this type engine after about 4500 miles on the oil. Typically, that type of problem would show up as aluminum (pistons), iron (Cylinders), and maybe chrome( Rings). The only thing to really note is the low viscosity, which was closer to 5w-20 then 5w-30 or 10w-30. It dosent seem to hurt anything though. all in all, nice report at 140k miles. Average mi/hr on oil 2000 mi/hr on unit 140k make up oil added 1qt aluminum 1 3 chromium 1 1 iron 2 8 copper 1 4 lead 1 4 tin 0 1 molybdeum 23 69 nickle 0 0 manganese 0 0 silver 0 0 titanium 16 0 potassium 1 2 boron 10 47 silicon 5 12 sodium 197 31 calcium 2121 2212 magnesium 75 123 phosphorus 726 713 zinc 752 855 barium 0 0 sus viscosity at 210f 53.6 should be 56-63 cst viscosity at 100c 8.36 should be 9.1- 11.3 flashpoint 385f should be 365f fuel 0.5 should be 2.0 antifreez 0.0 water 0.0 insolubles 0.2 should be 0.6 oil type mobil 5000 5w-30 interval 2000 mi subaru 2.5 dohc Link to comment Share on other sites More sharing options...
the3rsss Posted November 30, 2011 Author Share Posted November 30, 2011 First number is actual sample, second number in the average for this engine. Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 1, 2011 Share Posted December 1, 2011 Interesting. I'll have to stick a mirror in my engine tomorrow and get a good look at the wear patterns on the cams. I have lots of "clicking" at any engine speed that is too frequent to be bottom end noise, but not loud enough to be collapsed lifters. This gives me an idea that it may be dents in the cam lobes. Anyway [/offtopic] How much do you pay for the Blackstone reports? Link to comment Share on other sites More sharing options...
the3rsss Posted December 1, 2011 Author Share Posted December 1, 2011 25.00 sent me a free kit. easy enough to do. pulled a few ounces from the middle of my hot oil change . They supply the container, etc. There is a form to place comments or specific concerns. Got it back in about a week. sent me a hard copy and email. I feel it was worth it. As i said earlier, i had this motor apart and when i put it back together I heard the knock (weather got colder). Really put my mind at ease Link to comment Share on other sites More sharing options...
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