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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Lin on July 23, 2008, 05:41:54 PM

Title: 8v17-If it ain't broke, should I fix it anyway.
Post by: Lin on July 23, 2008, 05:41:54 PM
Although there were, and are still, many things to do as a result of the PO's neglect, the engine does not seem to have any real problems.  The party that sold it for the PO said it had an inframe rebuild not too long ago, whatever that means.  He claimed he had spent $12,000 on it but no paperwork.  Anyway, it seems to run very smoothly.  In spite of feeling a little hill shy from my experience a couple of weeks ago getting stuck climbing a hill, my errands today took me up a grade posted as 8%, and we did it at the top of first gear, about 15 mph all the way.  I am getting my confidence back!  So aside from that, it starts right up, I have not seen any smoke, it looks to be using about 1 gallon in 1000 miles, much of that probably to leaks.  Since I do not have any previous experience with large diesel engines though, I am wondering if I  should have it looked over, timed, and tweaked even though I have no immediate causes for concern.

Some of my errands today were installing a new CD player with a very handy remote that I could use while driving, getting $120. of diesel just to keep the tank wet,  $60. worth of gas for the generator, and about $100. worth of propane.  If my wife spent money like this, I'd be pissed!
Title: Re: 8v17-If it ain't broke, should I fix it anyway.
Post by: kyle4501 on July 23, 2008, 05:53:13 PM
Take it to a GOOD shop that knows the 71 series & have them check it over. It would be worth it for your peace of mind.
Title: Re: 8v17-If it ain't broke, should I fix it anyway.
Post by: Charles in SC on July 23, 2008, 07:15:34 PM
Get someone that has some experience to drive it if possible. Pulling an 8% in first gear does not sound to far out of line. Your engine might have the small injectors like mine does. That is ok if you do not need a hot rod, it will get better milage but will not race uphill like a car. When I check the oil in mine I always do it after the bus has sat for 8-10 hrs since being shut off at least and is level. I thought my engine was using oil until I learned about how to check it. It seems to take that long to settle. When I would stop and check it after only a few minuets it would be low, I would add it and it would blow it out making me think it was leaking, then the next time I checked it hot it would show low again and I would add more. A never ending cycle. Good luck and let us know what you find out!
Title: Re: 8v17-If it ain't broke, should I fix it anyway.
Post by: NJT 5573 on July 23, 2008, 07:43:27 PM
If there is no water in the oil, and no oil in the water, and it don't spit out the water, I would just drive it. Check all the water hoses and air hoses. All that engine gets is an oil/filter change, maybe an air filter. If you can afford to rebuild an 8V71 you can afford a newer bus.
Title: Re: 8v17-If it ain't broke, should I fix it anyway.
Post by: buswarrior on July 23, 2008, 08:08:44 PM
Hello.

Does the back of the bus accumulate oil after you drive it?

If not, you aren't leaking any to speak of.

Everything that drips underneath will be worn on the back after a drive on the highway.

And it takes less than a quart of leaking to make the back of the bus appear to be running in oil...

Don't be fooled!

For my cash, I'd keep a close eye on the fluid levels and drive it.

No smoke, and it goes, you have other things to spend cash on.

happy coaching!
buswarrior

Title: Re: 8v17-If it ain't broke, should I fix it anyway.
Post by: Lin on July 23, 2008, 11:21:52 PM
Thanks for the responses.  Just to be clear, my description of the engine was meant to say it all seemed okay to me.  I did not expect it to do better on an 8% grade.  Although I have thought of hooking up a temporary propane injection to see how it runs the same hill.  Even the oil usage seems reasonable to me.  It is possible that it is blowing out some excess, but I put 7 gallons in (or whatever the book said) when I changed the oil, and the brought it to the full line on the dipstick.  So I just think that I will try keeping at that full line.  My theory is that I will always be running fresh oil and could just change the filter periodically.  My curiosity was about whether I should bother to see if it would seriously benefit from some tuning.  I guess I am in between what Kyle said about peace of mind, and Buswarrior's implied suggestion to spend money where it is needed rather than on seeking perfection.
Title: Re: 8v17-If it ain't broke, should I fix it anyway.
Post by: kyle4501 on July 24, 2008, 05:30:51 AM
I'd consider letting the oil level finding it's own 'happy place'. if it is too high, it will get hit by the crankshaft. Note of how it drops per mile & you may see it drops quickly (blowing out the excess) at first then tapers off (what it leaks & burns) . . . .

Having the right someone look at it & drive it should get you started on the peace of mind.
If you're gonna add propane injection, I'd definitely have the motor checked for correct timming first. You need a good base line . . .
Title: Re: 8v17-If it ain't broke, should I fix it anyway.
Post by: edroelle on July 24, 2008, 11:48:14 AM
Adding oil is not like changing oil.  The oil in the pan has contaminants.  You want to change the oil as recommended.

I also would drive it until there was a need to have something fixed, or add a jake.  A gallon of oil for 1000 miles is a little high - if it really is a gallon.  I added 1/2 gallon of oil when it got to the low mark after sitting 15 minutes.   This brought it about 1/2 to full.

Ed Roelle
Flint, MI
Title: Re: 8v17-If it ain't broke, should I fix it anyway.
Post by: jjrbus on July 24, 2008, 11:49:01 AM
Gremlins got me!!! post deleted.
Title: Re: 8v17-If it ain't broke, should I fix it anyway.
Post by: RJ on July 24, 2008, 08:04:57 PM
Lin -

Right over the hill from you in San Jose is Royal Coach Tours.  Dan Smith, the owner, is also somewhat of a busnut.  Give him a call and ask him who he'd recommend there locally to "run the rack" on your MCI.  Once done, you shouldn't have to touch the rack for 50 - 100,000 miles, unless you add a Jake, in which you'll have to do it again.

Best time to check the oil is in the morning, before you start the coach for the first time.  You might also find that it happily stays about halfway between "add" and "full" on the dipstick for a long time - very common with the 71 series Detroits.

Change oil as per the recommendations in DA BOOK.  Simply adding fresh oil does not remove the contaminants from combustion, which can become quite acidic.

But most of all - drive it!  Best thing for your coach is to keep it moving, not sitting.

FWIW & HTH. . .

;)
Title: Re: 8v17-If it ain't broke, should I fix it anyway.
Post by: Lin on July 24, 2008, 08:18:00 PM
It is possible that it is not using that much oil.  It was down to the 2nd line, which I thought was one gallon.  When I added the gallon, it went above the full line.  It is now working its way down to the full line.  The whole process has taken around 1000 miles.  There is also the possibility that, if the in-frame was done as the PO said, the engine is till breaking in.  Anyway, I was not much concerned with the amount of oil.

Royal coach used to be just over the hill from me.  I now live down in Joshua Tree, which is near Twentynine Palms and about 40 minutes up the hill from Palm Springs.  There is just one diesel mechanic that I know of so far.  He says he has experience with DD, but I would assume that it is general rather than a specialty.  What does running the rack consist of and how much should I be ready to spend?
Title: Re: 8v17-If it ain't broke, should I fix it anyway.
Post by: makemineatwostroke on July 24, 2008, 09:35:38 PM
Lin if you have a good throttle response( the engine goes from idle to full throttle and back to idle quickly) if you are not blowing a excessive amount of black smoke and both sides of the engine are close to the same water temperature save your 2 to 3 hundred dollars and buy fuel run your engine between 1500 and 1900 rpms and you won't have as many leaks repair the small leaks and the 8v71 will be as loyal to you as a Lab puppy for years