Whoa Boy, Air Box Drains

[muldoonman]

Third trip out this year and 1991 86,000 mile 8V92TA is blowing oil out of the air box drains big time. Bought new check valves and installed , nothing wrong with the old ones after I got them off. Some Folks said in the archive section here said drive it hard and clear it out. Drove the pizz out of it this past few days , well 400 miles and at 2100 rpm's and it didn't help. Bought this coach over 6 years ago with 50,000 miles on it and didn't leak any up until this year. Used a couple gallons in 200 miles or what was in the reservoir tank. Stewart Stevenson in San Antonio bound next week to check it out unless somebody knows of a good mechanic in the Austin Texas area with 2 strokes and Those are kinda like Unicorns.  Don't know if it hurt, but the last 2 oil changes at Prevost Houston they dumped 9 gallons of oil in and I didn't catch it until halfway home and it was like now, all over back of bus. Outside motor looks like it always has, bright silver and no leaks. Always something.

[Dave5Cs]

Did they by chance use mutigrade oil?

[muldoonman]

No, always Delo 100 40 weight. Prevost changes every 8500 miles. I'm second owner of coach. Bought it with 50,000 total miles on coach. I have put 36,000 miles on it over 6 years. 86,000 now. Figure all rubber in and on motor has gotten stiff and breaking down. Changed antifreeze a couple years ago again at Prevost. They have done all maintenance since I've owned it.. Never hot. Just started using/blowing oil out air box drains and a lot. . Motor looks clean and silver with no leaks on outside. Have been around it since new from Prevost and Cole Conversions.

[Scott & Heather]

I'll be following this. I'm in San Antonio and would love to see your bus when it's here...


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[muldoonman]

You bet Scott. We're over here , or the bus barn is in Kingsland Tx. about 60  west of Austin. Gonna try and get it in next week some time will holler when I do. This is what mine looks like running down the road.

[chessie4905]

Did you get it hot on last trip or before trip?

[bigred]

I will be interested to see what the out come of this will be as I am having the same problem.Never noticed a problem until I had the oil changed at a local truck repair shop and they put multigrade oil in it .Did not stay in there .Did not put many miles on the bus with this stuff in there .I have had two different respected Detroit repair men tell me the same thing ,drive it hard .I have done this ,plus replace the drain valves .Now,mine does not leak while driving it ,only at idling .

[muldoonman]

Never hot. Does run about 190 to 195 degrees most of the time on back gauge in summer. Watch those gauges like a hawk after reading all the problems with heat on these things. Talked to Tommy at SS down in San Antone and he says he has a 2 stroke cat down their. Still a few down south of their running in the oil patch on some of the oilfield equipment. Still runs like a clock with no issues other than the spitting oil out the tubes. Just started after sitting a few months in a storage barn after I sold the place last fall and moved it to it's new barn here.. Mine has the back in a oil sheen and think it does it running down road to use that much. Reading/thinking about problems, maybe blower seals or god forbid rings. Motor has 86,000 easy miles since new in 1991. Knew the coach before and the Old Gent that owned it. I'm thinking just a old engine. Rubber does get brittle. Thinking about a $25,000 rebuild  and think my bus would make a good deer blind or camp house without the engine. LOL.

[muldoonman]

To add insult to injury, AC light on dash is lit up coming home and have a freon leak in OTR system. Charged it (added a few pounds of R134) before I let out. Maybe a nice Old Winnebago is in the cards.

[Geoff]

26 years, 86,000 miles.  I have 20 years and 75,000 miles on an out of frame rebuild.  I don't leak oil out the air boxes but I had a piston break.  It is quite possible your oil rings got weak from age.  I used to work on/rebuild a lot of diesel engines in boats that had hardly any hours on them and the rings would lose their tension because of age and low usage.  I doubt it's your blower seals if it spins okay.  Pulling the turbo off and looking for a LOT of oil on the lobes and turbo outlet would answer that.  A cheaper fix with those low miles would be to pull the pistons leaving the liners in place.  Hone the clyinders, put new rings on the pistons. And put it back together and go.  No warranty doing it this way.

--Geoff

[muldoonman]

Yeah we will see. Gonna take it in to Stewart Stevenson as I'm still not set up to work on anything in my new shop. Still waiting on Electric. Tools and boxes still at ranch I sold. Have a temp set up to get the 50 amp in to bus. Have a trip or 2 planned in the upcoming 2 weeks and hope SS can get it in and fixed. Who knows. After this will do my own stuff. Heck used to build the motors for our drag cars and these don't look to intimidating other than bigger parts. At the prices some folks charge to work on them a guy can mess up a time or 2 and still beat the shops deal. Can check the tubo/blower seal deal pretty easy. Might do that. Thing still runs good with no misses but guess a compression check will figure out the rings. It's only money , right??

[Geoff]

A compression test will not tell you if you have weak oil rings.  It will only give you the compression rings reading.  You can have good compression and bad oil rings, which is the norm for the 92 Series engine.

--Geoff

[Scott & Heather]

I'm actually here right now at SS getting some parts. Lol.


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[muldoonman]

Just got back in to house (Granite Shoals Tx.) Think I'll drive the puppy until she blows. Put about 3 gallons in it, 2 in the reservoir tank. Make a good deer blind. Wifey said she ain't going for a newer model. Heck she didn't know about this one until i brought in home. Threatened me, and I'm still here. Just a little lighter in the pocket.  Heck Scott if I head down that way for AC work will holler. Love to meet you folks.

[PP]

Don't want to lose track of this thread. Hoping it's a simple fix for you.