I reported some time back that when changing the oil I noticed a fair amount of metal sludge on the magnetic drain plug. I have been using Kendall GT-1 synthetic 10w30 and used a K&N HP-1007 filter for that interval.
The next change after that I used the same oil and OCI (3K) and this time used a Napa Gold filter. Drain plug was clean as a whistle.
Went back to the K&N to see if I could repeat the sludge. This time there was only a slight amount of metal sludge on the drain plug, much less than before but more than with the Napa filter.
The ony other time I noticed this sludge was at the first change from factory dino and the GM AC Delco filter, and much more sludge was present at that time.
I am assuming the sludge is some sort of iron based metal, but beyond that I do not know what, if anything, it means. I do have a pending Blackstone anaylsis and will do a follow up with the Napa filter in about 6-8 weeks.
Bob W.
The next change after that I used the same oil and OCI (3K) and this time used a Napa Gold filter. Drain plug was clean as a whistle.
Went back to the K&N to see if I could repeat the sludge. This time there was only a slight amount of metal sludge on the drain plug, much less than before but more than with the Napa filter.
The ony other time I noticed this sludge was at the first change from factory dino and the GM AC Delco filter, and much more sludge was present at that time.
I am assuming the sludge is some sort of iron based metal, but beyond that I do not know what, if anything, it means. I do have a pending Blackstone anaylsis and will do a follow up with the Napa filter in about 6-8 weeks.
Bob W.