[Bob]

This being a EGR engine ? correct? rite at change over time. Does it have a open vent to outside? To high of oil pressure? new one on me–Did oil pump go on super high (being smart-A) assume they mean crank case pressure. Odd that fan broke same time..Prob a pre existing condition that was just noticed…Can’t buy your Air compressor or turbo seal could add enough pressure to crank case to blow oil out of pan. Sheer volume of air required would be beyond their capacity. Another question for the 60 series guys–by 2000 I thought Detroit had the head bolt problem solved?Is a EGR crank case normaly a positive pressure situation when running? If cap was loose would oil be forced out? Bill I do wish you the best.. I would like to know the final outcome of your situation. The shut down couldn’t have been from low oil? Or fan belts being off? Bob

[Bob]

The guys are on it. Something stinks on their explanation to you. You should not have to supply them with info. They are seeing a shinny bus and $$$$.. I prob said what many others are thinking and are to nice to say. Shut down on low oil? or maybe fan belts off? or low coolant?? For 60 serries guys Did detroit have head bolt problem solved by 2002? Also do EGR engines have a normal positive pressure in crankcase and sealed /no vented crankcase? Would loose oil fill cap let oil be blown out of crank case? Bill please let us know outcome. Bob

[Archived]

didn’t mean to do it twice and decided when I thought first didn’t post to make 2nd less.. Then reconsidered.. That is just me. Luvrbus–Ken I know or usually dead on. The others sound like they have been there also. I know Jon has. Prob more of a diplomat than I. Learning curve for all! I learn something new every day… Bob

[Archived]

I agree with Bob on several points. First, I think it can be assumed something happened as a result of something being wrong. But what we don’t know is what signs led up to the event.

Was the event something that blew the cap from the oil fill tube and then the oil escaping a contributing factor to losing belts thus damaging the fan or did the loss of belts set off the chain of events?

I think it is safe to say that Bill did not start out with low oil levels. That might be a wrong assumption but I doubt it. What we don’t know, and what Bill might not know is the sequence of events (and there are multiple things that happened) and we don’t know what the dash gauges were showing. Was there a loss of boost? Was there a loss of air pressure? If there was when did that occur, before or after the loss of engine power? Like Bob and others I have way too many questions that likely will never be answered. Has anyone read the codes to see if some answers can be pieced together?

We also do not know if the bus had been exhibiting any signs of an impending problem before this event. Was boost always what it should be? was the bus smoking? was the bus building air pressure and holding it normally? What was the oil consumption? Did anyone check to see if the engine crankcase breather get pinched or blocked?

[glen]

Gil,

Detroit
uses a test to see if the compressor is passing along too much oil to
its outlet. Disconnect the compressor outlet line. Bleed the air system to less than 60psi with successive
applications of the brake pedal. Take a file card and draw a 2″ circle
on it. Hold the card 1″ away from the compressors outlet and run the
warmed-up engine at 1800 rpm’s for 60 seconds. If there’s an oil spritz
pattern on the file card in excess of the 2″ circle then the compressor
is worn and should be replaced

Bob,

Max for crankcase pressure is 5 inches of water, which is 0.18 psi, positive pressure.

[Dave]

David, good to know.

Thanks,

[Archived]

That low crankcase pressure suggests a very large inrush of air into the crankcase was required to blow the oil fill cap out of the tube or there is a blockage in the breather.

For such a low pressure limit I would guess there might be some restriction in the breather if the cap blew out.

[Davy]

What happen on this deal anyone heard ?

[Archived]

I’ll let Bill weigh in but I think they replaced the belts, cleaned up the engine and installed a new oil fill plug. From what I can gather, the plug blew out because it wasn’t tightened up. The crankcase pressure blew the oil out of the filler hole. I’m going to guess that the belts came off because of the oil and she shut down because of a high temp reading. I think that the shop re-thought their initial diagnosis as a little extreme. They cleaned her up installed a new plug, belts and topped off the oil and ran her for a while. Last I heard all is well. I think the diagnosis was an over aggressive service writer.

[Jim/Chris]

Is there a little more to the story? Was the breather tube blocked?

[Archived]

I told Bill in an e-mail that it’s possible the filler cap will no longer tighten. Had that happen before on the big trucks, no matter how hard you screwed it down, it wouldn’t seal.

Sure hope that’s all he has going on and all is well. Thanks for the update Rick.