Originally Posted by Weesew
It all seams to be fine. Pretty clean for a 140,000 mile motor. I spoke to the driver the bus was assigned to and he said the tube had been cracked for a while because the mounting bolt had came loose and the mechanic never fixed it. Told me it broke about a month ago. He had only driven the bus two Sunday’s to pick up kids since it broke. It ran fine on the 220 mile trip home. Water temp stayed right at 180 degrees and climbed to about 210 once when pulling a pretty steep grade, but cooled right down when descending. For an old bus, I think it will be fine.
I believe it was mentioned that the 3126 is fitted with several different old pans. Oil serves a cooling function as well as lubrication, so it is possible that a lower capacity pan could bump operating temperature up slightly... Larger capacity pans also serve to extend oil service life by slowing accumulation of dirt. Oil pan size can also be a factor in the dipstick assembly used, which is why I mentioned getting one for the specific serial number.