Hi all, I'm back with nothing too earth-shattering to report, but requesting any comments you might feel inclined to post, and TIA if ya do!
The latest (2nd) oil analysis of my high-mileage Honda, along with corresponding numbers from the 1st, follows.
This was a short interval because I wanted to find out quickly if the head gasket operation was a success. Got the oil changed just after the new HG, and kept it for about 2500 miles, which I figured was long enough to show any signs of leakage, but short enough to minimize damage if there was.
Oil: Don't know. Whatever brand 5w30 the Honda dealership uses. Didn't inquire except as to weight (BTW, as I mentioned in an earlier post, they don't use 5w20 at all, even on new cars).
PLUS a little bit of Red Line 5W30 left over in the garage, plus a little Super Tech 10w30 mixed with Auto-RX, also a left-over. I guess you could consider this batch to have had a maintenance dose of A-RX.
Interval: 2512 miles
Make-up oil: About 0.5 quart, but not carefully measured.
Oil filter: Honda OEM. Don't know if Fram-sourced or other.
Lab: Blackstone. No TBN.
Misc.: I ran Auto-RX, two treatments, in between these two analyses.
I'm wondering about the Al and Cr--they went up in absolute terms, and markedly up when measured ppm/mile. Any ideas why that might be? Sounds like upper-cylinder (piston/ring) wear?
Other wear metals look about the same, at least per mile, except lead, which seems to have fallen--woohoo!
Potassium and sodium looked a little high w/Red Line, but the consensus at the time was that they were additives. The only real evidence of HG failure was HCs in the cooling system and the failure of the coolant to return from the expansion tank overnight (oh, and a history of HG problems in this particular engine--seems they used inferior bolts, but I'm not complaining about 260K!)
Andy
The latest (2nd) oil analysis of my high-mileage Honda, along with corresponding numbers from the 1st, follows.
This was a short interval because I wanted to find out quickly if the head gasket operation was a success. Got the oil changed just after the new HG, and kept it for about 2500 miles, which I figured was long enough to show any signs of leakage, but short enough to minimize damage if there was.
Oil: Don't know. Whatever brand 5w30 the Honda dealership uses. Didn't inquire except as to weight (BTW, as I mentioned in an earlier post, they don't use 5w20 at all, even on new cars).
PLUS a little bit of Red Line 5W30 left over in the garage, plus a little Super Tech 10w30 mixed with Auto-RX, also a left-over. I guess you could consider this batch to have had a maintenance dose of A-RX.
Interval: 2512 miles
Make-up oil: About 0.5 quart, but not carefully measured.
Oil filter: Honda OEM. Don't know if Fram-sourced or other.
Lab: Blackstone. No TBN.
Misc.: I ran Auto-RX, two treatments, in between these two analyses.
Blackstone says there's no evidence of coolant in the oil, so it looks like the new gasket is holding. I'm going to return to Red Line with a longer OCI (circa 6K) and resample at the end to be sure. After that, I may start experimenting with various oil filters just for fun.code:
5.6K OCI / 260K 2.5K OCI / 268K
Red Line 10w30 mystery 5w30
Aluminum: 3 5
Chromium: 1 2
Iron: 10 6
Copper: 4 2
Lead: 4 1
Tin: 1 0
Molybdenum: 535 85
Nickel: 0 0
Manganese: 1 0
Silver: 0 0
Titanium: 0 0
Potassium: 11 7
Boron: 22 14
Silicon: 23 14
Sodium: 23 10
Calcium: 3171 2244
Magnesium: 10 8
Phosphorus: 1154 924
Zinc: 1365 1086
Barium: 0 0
I'm wondering about the Al and Cr--they went up in absolute terms, and markedly up when measured ppm/mile. Any ideas why that might be? Sounds like upper-cylinder (piston/ring) wear?
Other wear metals look about the same, at least per mile, except lead, which seems to have fallen--woohoo!
Potassium and sodium looked a little high w/Red Line, but the consensus at the time was that they were additives. The only real evidence of HG failure was HCs in the cooling system and the failure of the coolant to return from the expansion tank overnight (oh, and a history of HG problems in this particular engine--seems they used inferior bolts, but I'm not complaining about 260K!)
Andy