spots on back of bus 8v92 detroit

[robertglines1]

where to start oil leaks-- air box drains--other areas

[Hartley]

Well,

Let's see.. Spots on the backside..

If it drips or runs then you could have a problem.

If it's just dust spots it probably is a little of the oil mist from the breathers or airbox drains,
Then not a big worry. If you have an airbox drain recovery cannister it may just need to
be cleaned out and drained. Mine usually spits once and is clear for quite a while.
( Oil and unburned fuel can collect in the airbox tubes and when it drains will leave a telltale.)

Check around the back of the engine up at the top where the blower drive rubber
bushing is and see if it is weeping oil. Most will eventually. Some don't.. Duh...

Look at the bottom of the bell housing where the engine bolts to the transmission.
If you find a drip there it could just be seepage or a rear main seal leaking slightly.
Could also be around the transmission. Some weep or leak a little.

Hope that helps...

Dave...

[NJT5047]

Those 'spots' are an indication that a 2 stroke is running.   No spots = no oil. 
If you don't have a catch can on the airbox drains, those will dot the back up a little.  So will any other leak. 
Check for oil use.  Watch the oil levels of the engine and transmission and if no excessive use...wash the bus and forget it.   Now we can discuss 'excessive' oil consumption.   Normal oil consumption on an 8V92 can be considerable.   If it ain't dripping, it's likely OK.
Make sure that the crankcase isn't overfilled...the overfilled oil will get out pretty quickly.   
Looking over the engine for potential failures such as oil lines to the alternator or compressor, or power steering should verify what isn't leaking.   
As DrDave says, if it isn't running dripping on the ground when running (which will coat the back of the bus with oil) your probably don't have a problem.   
 
JR

[robertglines1]

thanks guys I thought I might have missed something easy. I do have catch cans. Since posting I found a leak on the oil drain return from the aircompressor. I also cleaned the air box drain valves and one was stopped up.

[Busted Knuckle]

thanks guys I thought I might have missed something easy. I do have catch cans. Since posting I found a leak on the oil drain return from the aircompressor. I also cleaned the air box drain valves and one was stopped up.

Spots? what spots? I didn't see no spots! 

Bob,
I really didn't see any! I meant to comment one how clean & shiney it was, but got side tracked once inside!
Wow, what a beautiful coach you and Judy have!   BK