More Air Drain Isuses

[bigred]

I am beginning to get concerned about the amount of oil dripping from my air drains on my 8V92TA DDECK. Have had the engine looked at by two different mechanics and their diagnoses was that the engine has never gotten broken in and that I need to drive the H--- out of it (it has about 155 thousand miles and was never a passenger bus).I have been trying to give the engine a work out such as running it in 3rd and 4th gear when on side roads and short trips but seems like the harder I work this thing the more it spits up. Does not drip at all on the road but is awful at idling speeds.Even on fast idle and now it has gotten to where it leaks a lot more on the left side than on the right .I mistakenly put a gal of DLO 400 in it and it seems that was about the time all this started .Have any of you had similar experience and if so what did you do for it?? The bus currently has Rotella 15/40 in it . 
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[luvrbus]

Change the oil to Delvac 1240 and run it no idling it will clear up your wasting time if you don't get to operating temp for a couple hundred miles   

[chessie4905]

There is a difference between running it hard and just running it at high rpm. You need to pull some grades making it work hard. Watch engine temps though.A good 100 mile trip with a real workout should do. We've got some nice grades in PA. that all do it. Pretty much most of the rest of thecountry is flat like Kansas.😊

[robertglines1]

You rite at the end of the 8V92 in prevost and for some reason they recommended 10 W 40 for engine use. That didn't work out!! Many went back to the straight 40 wt and solved their problems.  Many fleets ran 8V and 60 series that use 10W40 .They only wanted to buy one type. Just info FWIW. I ran 40W in my 89 prevost 8V92.

[muldoonman]

Doesn't sound like your problem but, Run Delo 100 40 wt. in mine and had oil changed at Prevost Houston and they dumped 9 gallons in it. All 3 cases i put out on the floor. Noticed after I got home and started it a week later for a trip and it was dripping out of tubes. I ran it as I didn't want to dump any out and 40 miles later it's back to full mark on stick. Hasn't used any the last (2) 400 mile trips out. 

[DoubleEagle]

You should definitely only use straight 40 weight that has Detroit low-ash specs in a 2 cycle, period. If your air box drain check valves are operating correctly, they release what has accumulated when you are at low idle. They close when above idle.

[DoubleEagle]

You should definitely only use straight 40 weight that has Detroit low-ash specs in a 2 cycle, period. If your air box drain check valves are operating correctly, they release what has accumulated when you are at low idle. They close when above idle. (Sorry - clicked twice)

[luvrbus]

The 15/40 or the  Delo 400 is not going to make drip more from the drain tubes you just need to change to Delvac 1240 and work it then it will clean up,that engine probably has a lot of idle time since you been working the bus on for a year + and you could have a blower seal going bad also

[bevans6]

You might also service the check valves, mine seal the chamber above an idle so no leaking at all at high idle.  I seem to recall they are serviceable, but new ones are quite cheap.

[bigred]

Thank's a lot guy's .I have had the air drains  and motor checked last by David at David's Coach Service .As a matter of fact he said that the air drains were not dripping that bad but he checked it right after we drove it about a 100 miles but I brought it back to the storage lot "And The Spots On The Ground Tell The Story".Sounds like the making's of a good country song doesn't it ?? .Actually ,Luvrbus,I have idled it very little on low idle .I usually let it go on low idle for a very short time then I hit the high idle button.It leaks even on high but not as bad.Best I can remember high idle is about 1100 rpm .Actually ,it is almost two years that I have been dumping time and money into this thing and I have about reached my limit.I swear,I fix one thing ,go back two days later and three more things are wrong with it .Excuse the pity party!! Back when I drove truck's and buses ,I don't remember all these issues with the older 8V'S  .Guess it is like Subaru automobiles,as long as they kept it simple you could put a million miles on them but then they started fancying them up,and now you are lucky to go a 100,000 miles without major repairs.I am going to change the oil and see where that puts me.I really do hate to give up on this old coach as it drives runs and look's great.

[luvrbus]

They still build up on high idle,DD has 2 settings for the check valves 900 rpm and 1200 rpm.A fast idle is one gadget I never used they could have left it off for my part and it would have never been missed 

[uncle ned]

Big red   If David said it was good then its good.  On my 6v92 it has the tank that Detroit offered and it gets drained every time it goes to Davids.


If Mrs David oks the work then it is good.  think the world of both of  them.

uncle ned

[buswarrior]

bigred, change the oil to straight 40wt, fill the radiator, fill the fuel tank, fill the water tanks for ballast, and head north into the Appalachians and then empty the fuel tank climbing mountains.

You may know better places, but I'd include heading up I77 and run back and forth over the top at Fancy Gap in Virginia a few times, carefully observing the temp, and any changes between climbing attempts. Make that engine work.

4-way flashers on if your speed slips 15% below the posted speed limit. Look far ahead to gauge your closing speed on any heavy trucks so you can choose when to get out around without cutting anyone off, and without having to lift throttle.

Watch the temp closely, make it prove itself to be trouble free in that department. Watch the exhaust closely.

Memories and attention being what they are, set up a video recording device on a stand/tripod of some sort up over a shoulder looking down, so you can forget about it, to capture the dash gauges and you can do an audio play by play to review later the things you get mixed up, or didn't notice at the time.

When the fuel tank is empty, you can go home.

Big grin on your face after a day or two of driving, that's optional!

The trouble with big horsepower, it doesn't get to work hard as often, hiding and making all sorts of problems.

The only reason to normally idle, low or high, is if you need to build air in order to go for a drive. Otherwise, only run the engine to drive it.

For reference, my stock MC8 with 270 HP climbs Fancy Gap between 40-45 mph in 3rd gear. An MCI EL3 with 400 HP climbs at 50 mph in 4th gear full of kids and a week's worth of baseball equipment.

happy coaching!
buswarrior

[DoubleEagle]

When David's Coach checked the air box drains, did they actually put in new check valves? They are not easy to get to and the labor charge is probably more than the cost of the check valves. They can be cleaned, but for all the trouble involved, they might as well be replaced with new.

[Oonrahnjay]

bigred, change the oil to straight 40wt, fill the radiator, fill the fuel tank, fill the water tanks for ballast, and head north into the Appalachians and then empty the fuel tank climbing mountains.

You may know better places, but I'd include heading up I77 and run back and forth over the top at Fancy Gap in Virginia a few times, carefully observing the temp, and any changes between climbing attempts. Make that engine work....   

    Yeah, Fancy Gap is good but it's a ways away from Asheville.  He could go I-26 up toward Johnson City or go east on I-40 about 25 miles and them come back up "Old Fort" grade.  Both of those would be a good workout and right in his backyard.