I have been chasing this one for ~ 6 months and have done the following by myself or through a shop:
1. Front seal replaced - the one behind the fan (self)
2. Breather box sealed (Trafton)
3. Dipstick boot replaced (Trafton)
4. Oil cooler replaced (Trafton)
5. Push rod tubes sealed (Trafton), redone by Colin and I
I have gone through 3/4 quart in the last 70 miles. When I park I get a pool up to a foot in diameter from underneath the fan housing, several pools under the R heater box, and a pool under the L heater box. Case pressure seems minimal. There is negative pressure at the oil fill tube at idle, and what I would consider a small amt of positive pressure at higher rpm. 2 shops have stated that case pressure does not seem to be excessive, but that there is some.
Yesterday (saturday) I followed Colin's instructions and permatexed the right cylinder head washers/nuts (question - should there be "play" in the bolts?). Prior to this, I spent 4+ hours cleaning (and cleaning and cleaning). For as much time as Colin and I spent cleaning oil 70 miles ago, the amount of oil present was a bit unsettling.
I will use rear to mean rear of bus.
Starting from the top, there was oil accumulated right front and underneath/around the breather box area, but the box itself seemed dry. The breather tube was wet form the box about 3 inches out. Oil also in rear of the fan under the dipstick tube and oil fill tube. Moving underneath, the first thing that I noticed was that the tubes from both heater boxes to the heater fan were not seated and that there was oil coming out where both of these should connect to the exchangers. Also, there was oil dripping from where the left heater box meets the exhaust, which then appeared to drip down the bottom of the fan housing. Lots of oil on top of the left lower tin. The area above the push rod tubes was wet, but the tubes themselves did not appear to be the source. There was oil between the oil cooler and the front of the fan housing, with the foam strip on the bottom of the cooler very wet. Not sure if the cooler was the source - could have just been dripping down the fan housing? Bottom of oil filter wet.
After cleaning, permatexing and closing back up, I idled in the driveway for 30 min. Saw drops form below where the frontmost pushrod tube on R side meets outer housing (? sorry 'bout my uneducated terminology). Also some drops on bottom center of fan housing. I let it sit overnight and this morning saw oil on ground under the fan housing center, oil accumulated where oil fill tube pass through tin (on bottom side of tin). There was oil on the ground underneath the hole at the front of the left heater box. Oil where both heater boxes meet the fan housing. There was also oil on the ground underneath the frontmost right push rod tube, where it meets the outer housing. It looked to have been dripping from above, and down the outside of the head, maybe??? Top of the engine completely dry.
Finally, I drove it 10 miles on the freeway today and saw the following:
1. Lots of oil dripping from front hole in left heater box
2. Lots of oil coming from where both heater boxes lead to fan, and where right heater box meets exhaust
3. Oil on bottom of oil filter and minimal amt above where it meets the cooler.
4. Oil on bottom of fan housing coming from rear center.
5. Oil fill tube coated with oil after it passes through from top of engine. Top of oil fill tube was dry.
6. Oil dripping from the outer housing for the frontmost right pushrod tube, seemed to be coming from above on the outside of the head.
7. Lots of oil in in rear of fan on top (accumulating in center and under dipstick and oil fill tube)
8. Oil on back of fan housing on top next to and to the right of the breather box and tube, toward cyl #2 area.
Sorry for all of the detail
I am really at the edge of my abilities here and appreciate any help.
If there is a local who has an hour or 2 to look this over and help with identifying the source I have burgers and beer
Thanks to all in advance!
