With all the debate on "which is the best oil" and "how long should I run it for" and what are ways I can test the health of my engine, I thought I'd do a couple of oil tests, stop speculating and see the results.
2 sets of tests attached, one with every interesting results. OEM tall oil filter on both.
1.) Mobil1 10W-30 Syn. 1500-2000 miles from a trip up from LA - Seattle. Mainly freeway driving with some stop n go and some, though relatively few boosting. When wife drove, she averaged 23 MPG on the freeway. Most of the time when I drive, I get 10 - 15 MPG
Like I said, I did some boosting, twistys, but in general much lighter than the average day
In short, fairly super readings. Terry @ Dyson asked when the motor was rebuilt (it has about 90K) I said, I don't think it has been...
Highlights:
*Most wear items are low/0.
*Resisted fuel dillution very well.
*Some glycol which is questionable, but went away on the next reading.
Hypothesis:
A.) Good proof that "Mobil 1 is good enough." Under normal wear n tear on N/A nice driving mode, 3000, even 5000 easy miles should be no problem.
2.) Amsoil 10W-30 Synthetic. Amsoil is considered by many, including Terry who has done thousands of oil analysis, to be a very excellent oil, with better characteristics than Mobil 1. Results are from a 6+ month period about 3000 miles between June & January. Much of driving was stop n go/WOT, 2 AM in 30F and less. Not your average day... In short, oil took quite a pounding and not the results I wanted it to be. However, the oil also sat in a bottle for over a month in garage, sub 30F meantime picking up moisture skewing the results somewhat.
Highlights/Lowlights:
*High fuel dillution.
*Sheared to 5W-20 (fuel dillution is part of the problem)
*High silicone content - suggests clogged air filter.
*Unexpected Vanadium content.
*Worse: 7 PPM titanium content.
Hypothesis:
*3000 miles and 6 months on this type of conditions, even with Amsoil is too much. Changing it at 1500 miles would have been better.
*I have the Uni Filter. I'm lazy at maintaining it.. too much work, hard to get it right, and it seems like you have to do it every 3000 miles or less. It was about 7000 miles old. This is why I went to stock filter recently
*Given aftermarket fuel management, While "Hi-Boost" SC, a lot more fuel dillution will occur and affect the oil. However, see below which might also explain more fuel..
*I have 100 octane in a barrel tha I mix every now n then. Apparently these barrels can get vanadium in them.. and I think I picked some up.
*I replaced my fuel filter for good measure.
A few caveats/stupid mistakes:
*As soon as I saw the titanium content, I started digging in. There are only two titanium components (afaik) in the car - the rod, and aftermarket retainers n valve springs (bleah, by the previous owner..)
-Pulled the plugs. They were carbon fouled, as 10k miles before. From talking to Shad n others, not too unexpected and not necessarily bad b/c well, the car does go through a lot of fuel at WOT...
--IN ADDITION, cylinder #2 coil was loose Bad, bad... it was loose about a couple of inches up... Pulled the plug and it was "brownish/red" at the top.
Also, my valve cover plates are removed, the seals around the hatch are wearing out and while I try to use a towel to cover the rear bank, I still get water/moisture in there. Need to fix this..
--IN ADDITION, I remember that the #1 cylinder about 9 months ago... I had replaced the spark plugs but damaged 1 while handling it. I put 5 in, drove the car a few days and then replaced #1. The car was misfiring during this process... I didn't think it was that big of a deal but apparently, I learned later from John Zahn, that the misfire was pinging and unburnt fuel was washing down teh cylinder wall. Woops :redface:
-Next, Did a compression check. 5 cylinders came in at 200-210, the #1 cylinder @ 185-190--Numbers in general are very strong, but the fact that 1 year ago #1was also in the 200-210 range says that it's not good. 20 psi difference does not make me happy. Above detail can expain why..
--Had ZahnTec do a leakdown test. 120 PSI pushed down each cylinder. All but #2 came in at 15%. #2 came in at 20%. All within NSX specs. I'm told that these numbers are "higher" than a lot of shops b/c they don't often pump as much psi in the cylinders. Added a little bit of oil at the top of the cylinder, and everything was very close - suggestions leakage past the piston rings (washed down cylinder..)
--He also did a comp check and similar results as mine, 230 in 5, 210 in #1 but it's the difference in our gauge;his tends to be inflated a little bit than others (snap-on, go figure..)
So, stupidity caused me damage in cylinder #1 & #2, affected the oil, but it's not catastrophic. By most measures, it's "still pretty good." I'm bumming, but based on those results, I don't need a tear-down.
This still doesn't solve the most important issues... where is the titanium coming from?
A few possibilites:
1.) During high-rpm driving/bouncing off the rev-limiter, one of the titanium retainer had too much stress/rubbed and resulted in temporary content. A new oil analysis will tell us if this is the case.
2.) Permanetly rubbing/snapped titanium retainer. Shad told me these aftermarket pieces have gone bad before.... Damn, STOCK IS BEST!
3.) Snapped Rod. Doubt it b/c if the rod goes, you'll know, you'll hear it, and the titanium content would be through the roof. 7 ppm is a lot more than 0/1, but it ain't ..100 or more.
4) As per titaniumdave, crank Thrust Washer out of spec, touching the crank journals and causing particles from the titanium to end up in the oil.
5.) Fill in the blank: ____________
Unfortunately, I can't validate 2,3 or 4 without taking the motor and head apart which I'm not looking forward to what's going to be ~$1000 in labor alone... Car had valve adjustment 15K miles ago and Zahn doesn't hear/believe it needs another adjustment.
Thoughts welcome. Please don't turn this into a "my oil is better than your oil" thread though!
2 sets of tests attached, one with every interesting results. OEM tall oil filter on both.
1.) Mobil1 10W-30 Syn. 1500-2000 miles from a trip up from LA - Seattle. Mainly freeway driving with some stop n go and some, though relatively few boosting. When wife drove, she averaged 23 MPG on the freeway. Most of the time when I drive, I get 10 - 15 MPG
Like I said, I did some boosting, twistys, but in general much lighter than the average day In short, fairly super readings. Terry @ Dyson asked when the motor was rebuilt (it has about 90K) I said, I don't think it has been...
Highlights:
*Most wear items are low/0.
*Resisted fuel dillution very well.
*Some glycol which is questionable, but went away on the next reading.
Hypothesis:
A.) Good proof that "Mobil 1 is good enough." Under normal wear n tear on N/A nice driving mode, 3000, even 5000 easy miles should be no problem.
2.) Amsoil 10W-30 Synthetic. Amsoil is considered by many, including Terry who has done thousands of oil analysis, to be a very excellent oil, with better characteristics than Mobil 1. Results are from a 6+ month period about 3000 miles between June & January. Much of driving was stop n go/WOT, 2 AM in 30F and less. Not your average day... In short, oil took quite a pounding and not the results I wanted it to be. However, the oil also sat in a bottle for over a month in garage, sub 30F meantime picking up moisture skewing the results somewhat.
Highlights/Lowlights:
*High fuel dillution.
*Sheared to 5W-20 (fuel dillution is part of the problem)
*High silicone content - suggests clogged air filter.
*Unexpected Vanadium content.
*Worse: 7 PPM titanium content.
Hypothesis:
*3000 miles and 6 months on this type of conditions, even with Amsoil is too much. Changing it at 1500 miles would have been better.
*I have the Uni Filter. I'm lazy at maintaining it.. too much work, hard to get it right, and it seems like you have to do it every 3000 miles or less. It was about 7000 miles old. This is why I went to stock filter recently
*Given aftermarket fuel management, While "Hi-Boost" SC, a lot more fuel dillution will occur and affect the oil. However, see below which might also explain more fuel..
*I have 100 octane in a barrel tha I mix every now n then. Apparently these barrels can get vanadium in them.. and I think I picked some up.
*I replaced my fuel filter for good measure.
A few caveats/stupid mistakes:
*As soon as I saw the titanium content, I started digging in. There are only two titanium components (afaik) in the car - the rod, and aftermarket retainers n valve springs (bleah, by the previous owner..)
-Pulled the plugs. They were carbon fouled, as 10k miles before. From talking to Shad n others, not too unexpected and not necessarily bad b/c well, the car does go through a lot of fuel at WOT...
--IN ADDITION, cylinder #2 coil was loose
Bad, bad... it was loose about a couple of inches up... Pulled the plug and it was "brownish/red" at the top.Also, my valve cover plates are removed, the seals around the hatch are wearing out and while I try to use a towel to cover the rear bank, I still get water/moisture in there. Need to fix this..
--IN ADDITION, I remember that the #1 cylinder about 9 months ago... I had replaced the spark plugs but damaged 1 while handling it. I put 5 in, drove the car a few days and then replaced #1. The car was misfiring during this process... I didn't think it was that big of a deal but apparently, I learned later from John Zahn, that the misfire was pinging and unburnt fuel was washing down teh cylinder wall. Woops :redface:
-Next, Did a compression check. 5 cylinders came in at 200-210, the #1 cylinder @ 185-190--Numbers in general are very strong, but the fact that 1 year ago #1was also in the 200-210 range says that it's not good. 20 psi difference does not make me happy. Above detail can expain why..
--Had ZahnTec do a leakdown test. 120 PSI pushed down each cylinder. All but #2 came in at 15%. #2 came in at 20%. All within NSX specs. I'm told that these numbers are "higher" than a lot of shops b/c they don't often pump as much psi in the cylinders. Added a little bit of oil at the top of the cylinder, and everything was very close - suggestions leakage past the piston rings (washed down cylinder..)
--He also did a comp check and similar results as mine, 230 in 5, 210 in #1 but it's the difference in our gauge;his tends to be inflated a little bit than others (snap-on, go figure..)
So, stupidity caused me damage in cylinder #1 & #2, affected the oil, but it's not catastrophic. By most measures, it's "still pretty good." I'm bumming, but based on those results, I don't need a tear-down.
This still doesn't solve the most important issues... where is the titanium coming from?
A few possibilites:
1.) During high-rpm driving/bouncing off the rev-limiter, one of the titanium retainer had too much stress/rubbed and resulted in temporary content. A new oil analysis will tell us if this is the case.
2.) Permanetly rubbing/snapped titanium retainer. Shad told me these aftermarket pieces have gone bad before.... Damn, STOCK IS BEST!
3.) Snapped Rod. Doubt it b/c if the rod goes, you'll know, you'll hear it, and the titanium content would be through the roof. 7 ppm is a lot more than 0/1, but it ain't ..100 or more.
4) As per titaniumdave, crank Thrust Washer out of spec, touching the crank journals and causing particles from the titanium to end up in the oil.
5.) Fill in the blank: ____________
Unfortunately, I can't validate 2,3 or 4 without taking the motor and head apart which I'm not looking forward to what's going to be ~$1000 in labor alone... Car had valve adjustment 15K miles ago and Zahn doesn't hear/believe it needs another adjustment.
Thoughts welcome. Please don't turn this into a "my oil is better than your oil" thread though!
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