Originally Posted By: aaonms
1999 Jeep Wrangler with the mighty 4.0 here too.
I am the original owner and live in northeast Florida so it gets warm here.
Some moderate trail riding these days, but hard core off roading is a thing of the past.
It is not my DD, more of a weekend toy now and owing to this, Oil Changes are usually once a year as I typically hit the 5000 miles mark at about that same time.
To make a long story only slightly shorter, I have been using Blackstone for UOA since 2003 (28,882 miles on the Jeep/Motor).
Oil of choice then was Mobil 1 10W/30.
Over time, the Lead trended up for the motor as well as compared to Universal Averages.
At first, Blackstone suspected a particle streak and not bearing related. Other values looked good.
Flash forward not quite five years to 2008 (48,553 miles) and there was a substantial increase in Lead as well as in Copper and Tin.
By 53,306 miles in 2009, Lead stabilized, but was still high. At this point, Blackstone recommend I consider switching brands of oil or moving away from synthetics.
I switched to Valvoline SYNpower 10W/30 and Lead came down for a bit, but is again on the way up.
Blackstone’s comments from the most recent Oil Change that had 4121 miles on the oil, total mileage 69,503 was: Not a lot of change since 2011, though you are getting a little more bearing wear than you used to. We've seen lead out of this engine before, and it didn't amount to much, so maybe it will drop again. We're a little concerned, though, seeing copper and lead both reading high. Typically this shows bearing wear and it could be the result of hard operation, or it could show a problem brewing. This engine is known for antifreeze, though it's hard to say for sure because the sodium in this oil masks sodium that might be coming from coolant. Stay at 3K-4K miles to monitor.
Am considering dumping the oil at 2000 miles, sending a sample to Blackstone, and also changing brands again.
I had good results with Rotella in several VW’s (both turbo and NA) and am also pleased with the German Castrol in my current turbo MINI.
While it pains me to think non-synthetic may be the way to go, some readings here and on several Jeep Forums makes me wonder if this may not be the way to go.
Iirc KCJeep likes PYB 10w-30 and has uoa showing low wear meals using it. I think rotella conventional also shows well in the jeeps straight 6.
Pm KCJeep. He'd be the guy to ask when it comes to these engines. He has alot of experience.
Elevated lead with M1 way. I read that so often in relation to M1 its hard for me to not get sucked in to feeling that its just not all that great of an oil.
It used to be the best and was THE standard in synthetic oil,now I don't feel its any better than anything else on the shelf. PU in my opinion is the daddy now,not including boutique and mail order.
Have you considered redline lubricants. I think your engine is a prime candidate. I'll bet lead drops significantly after the second or third sample after the oil washes out the old oils