Well... I did my complete oil and filter change. Added the correct measure of zinc additive and now have that task checked off my list. However, all is not without some concerns.
Here's why:
The last oil change was done by the previous owner and he used an unspecified systhetic. When inspecting all areas for leaks, non were found (prior to purchase). The truck sounded and performed well. Everything remained leak-free after the M35A2 was driven 40 miles to my place. I checked again... all looked good and leak-free. As I mentioned in a previous post, the oil had turned very thin, dark BLACK and had the smell of charcoal/soot, but prior to today I had not discovered any leaks from the system.
Today, I warmed up the truck and then drove it about 6 miles and waited about 10 minuted to prepare for the oil change. I then got under the truck to drain the pans and to my shock... there was a kind of weeping of the black synthetic oil CLEARLY visible. At first, it kinda looked like 'condensation' to me, but a wipe with a clean, white rag proved it was in fact the thin, black oil.
Well... I went ahead and drained all of the synthetic out of both pans. Changed out the two old filters with new and then added the new oil and zinc additive to spec.
Once all was completed... I warmed up the truck and then drove it another 6 miles. It runs much better (at least seems that way to me) than it did prior.
I've checked for additional leaking (after having wiped everything clean) and so far nothing new is weeping out, but it's only been a couple of hours.
Now... that's not all that I'm worried about. In the bottom of the drained oil I discovered what looks to me like 'casting metal', or shavings. I have not yet found a magnet good enough to check to see if they are steel, brass, or some other metal, but my wife is searching for one as I type.
Any thoughts?