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Old 07-22-2020, 06:34 PM   #1
New Member
Join Date: Oct 2019
Posts: 5
89 MCI 8v92 questions

Gong to go look at a conversion I want to purchase soon. Engine is an 8v92 turbo, in an 89 MCI 102A3 bus. Rebuilt 65K miles ago.

My question is, what do I look for ? I'm looking for deal killers. $2000 fix I'm fine with. $5000 fix maybe we need to talk about price. $10,000 fix, well, maybe not.

I'm going to have it inspected, but beyond that, what do I look for ? Any random advice is appreciated too.

Thank you.

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Old 07-22-2020, 08:54 PM   #2
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Join Date: Apr 2012
Location: So Cal
Posts: 3,234
Year: 1935
Coachwork: Superior
Chassis: Chevy
Engine: 317 ci/tid / Isuzu
Go to Bus Grease Monkey


They know everything about what you are looking at.
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Old 07-23-2020, 02:51 AM   #3
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Join Date: Dec 2013
Location: SoCal
Posts: 392
Year: 1989
Coachwork: Crown Coach
Chassis: 40ft 3-axle 10spd O/D, Factory A/C
Engine: 300hp Cummins 855
Rated Cap: 91
Originally Posted by aegis4244 View Post
Gong to go look at a conversion I want to purchase soon. Engine is an 8v92 turbo, in an 89 MCI 102A3 bus. Rebuilt 65K miles ago.

My question is, what do I look for ? I'm looking for deal killers. $2000 fix I'm fine with. $5000 fix maybe we need to talk about price. $10,000 fix, well, maybe not.

I'm going to have it inspected, but beyond that, what do I look for ? Any random advice is appreciated too.

Thank you.
Look for some previous threads I replied to concerning used coaches. I'll not go into details here again. Good rule of thumb is "If you Have To Ask...." and you don't have limitless funds, consider Where Angels Fear To Tread. Think, Boat, Airplane, 100 yr old fixer Upper. You get the picture. What you don't know will HURT you.
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Old 07-23-2020, 03:07 AM   #4
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Join Date: May 2019
Location: Lebanon, Indiana
Posts: 911
Year: 2000
Coachwork: Winnebago
Chassis: Ford F53
Engine: Ford Triton V-10
Rated Cap: currently 2
Admittedly an MCI coach is a different animal than a school bus so I only know of a few people here who have any experience with them. It's nice that they're heavier duty rigs than school buses but along with that comes heavier duty maintenance and repair bills as well. I don't know what kind of deal you may be getting on this one but more than a few people have found good deals on these types of buses only to go broke trying to maintain them. Not trying to dissuade you, only to point out the realities and contrasting that with what you may have read here which is relating almost exclusively to school buses.

A professional inspection is definitely a must-have before moving forward with the purchase. Just like school buses, motorcoach tires are expensive so the newer and more tread they have, the longer you will postpone the expense of replacing them. If it's been out of service for several years, the tires may look okay with tread depth but show signs of age and weathering. Check the date codes on them and anything older than 8 years plan on immediate replacement.

Look for fluids on the ground under the engine compartment as well as in and around the engine. Again, if it's sat for a long time this may be dried smudges and not recent leakage but still indicative of something leaking, a seal or gasket or something that's going to need attention sooner than later.

If it's driveable and you can go for a test drive, check for play in the steering and any shimmy or vibration. Like any vehicle, ball joints and bearings wear out over time and an alignment on this type of vehicle is very specialized.

I think by this model's era aluminum was utilized especially in the exterior. While it doesn't rust like steel, it does corrode and also any places where it's in contact with or proximity to steel the aluminum will show signs of galvanic corrosion which is a slow chemical reaction between the two types of metal. Being over 30 years old, this could become a significant maintenance factor. Aside from that, the underpinnings of the suspension and load-bearing components are still solid steel so those should be inspected for conventional rust.

If the conversion was professional, it is likely to be solid but dated. If it was homemade, there's no telling what corners may have been cut. Again, sometimes a well-intentioned DIYer bites off more than they bargained for with these beasts and their conversion budget is depleted by underlying mechanical necessities which shortchanges the quality of the interior conversion.

Was the interior lining removed and the walls reinsulated? Were some of the windows replaced with solid panels and if so how was that accomplished? (i.e. welding or blanks inserted). Generator, rooftop air units, plumbing, all should be checked for functionality or discounted from the purchase price if you're going to have to repair/replace them just to make the rig operable. The interiors and living systems are probably not going to fall to the mechanic who performs the roadworthy inspection so you'll want to double-check these yourself.
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Old 07-23-2020, 11:20 AM   #5
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Join Date: Oct 2015
Location: Tampa Fl
Posts: 51
Year: 1989
Coachwork: MCI 96A3
Engine: DD 8V92TA
I have a 1989 MCI 96A3, same bus 6 inches narrower.

Check all the fluids, the 8V92 engine uses a special oil, straight 40 w CF2 low ash, Delo 100 is a good choice and available at Orielys, most Detroit 2 strokes will leak some oil and you will need to check it and add occasionally.

The engine oil dipstick will be on the lower curb side of the engine when looking at the engine from the back of the bus.

Check the Transmission fluid, dip stick will be on the driverís side access hatch in front of the air cleaner, check to see if it is full and clean.

Check the power steering fluid, there should be a sight glass on the curbside of the engine looking straight into the engine compartment past the engine from the back of the bus.

Check the oil level in the blower drive at the top of the giant fan belt, there will be a sight glass.

Check the condition and tightness of the fan belt, if the original piston is still there it will tighten up as the air pressure builds.

Above the blower drive on the tank there should be a sight glass for the coolant level.

If possible get an oil sample and have it analyzed, this will give a good indication to the health of the engine.

65,000 is nothing for a Detroit, watch the exhaust when starting see how long it takes the smoke to clear, a small amount that clears quickly could be ok, thick smoke that takes a while to clear could mean expensive issues.

If you are not familiar with the Detroit 8V92TA it is different from any engine you have dealt with before, it is a two stroke, with a blower pressurizing the intake and a turbo feeding the blower. A very dependable engine when running good, but expensive to fix when it breaks, they have been out of production for a number of years and good mechanics that understand them are getting hard to find, none the less these are good engines with a loyal following, if you are able to do your own work a lot of help can be found on the net, check out the Bus conversion Magazine forum,

How long does it take the air pressure to build? You need at least 100 psi to move the bus, 120 psi is good, listen for air leaks, unless they have been meticulously maintained they all will leak air, The air powers the brakes and the suspension, so big air leaks are bad.

Check all the air suspension Bags, one on each side front, two for each side drive axle one for each side tag axle, look for air leaks and dry rot, they are not terribly expensive (Relatively speaking, everything on a bus is expensive) or that difficult to replace, but something to consider.

Check the tires for tread and age anything older than 8 years is suspect, figure around $500 per tire to replace.

Tire pressure should be 90 to 100 PSI.

Examine all the lugnuts, they are torqued to 450 Lbs, most have been abused, not expensive but a lot of work to replace, drivers side lugnuts are left-hand threads.

Check all the Hubs on the steer and tag axles there will be a cap in the center there should be a visible amount of oil in them, if it is low suspect the wheel seals to need replacing and the bearings to need inspection and/or replacement, if the wheel seals are bad then there will probably be oil on the brake shoes as well.

If you can get under to check the brakes, the shoes should be visible in the drums, look to see if the shoes are worn past the line in the middle, look to see if there is a visible space between the drum and the shoe, the slack adjusters might (probably) need to be adjusted, look to see if the wheel seals are bad and the shoes are oil soaked.

A word of warning here, be sure not to get under this bus while it is just being held up by the air suspension or just a jack, this thing weighs 13 tons, if it comes down on you, you are dead.

These are some of the things to check to possibly make a safe ride home, there are many more things that will need to be serviced if you buy it.

My Bus was fresh out service and it had not been maintained very well for at least 10 years and there were some very shady things done that were not visible on a quick inspection, so beware.

Feel free to ask any questions.

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