Mci bus detroit diesel 8v71 tear down. Broken valve and over heated engine

[@madusmaxamus8670]

I worked on gas engines for 45 years. I have owned diesel's and had a good Detroit mech. to take care of them. He scared me by setting the governor at 2400 because of a bad range in the manual trans (1000 rpm shift). Never had a problem with it. I like your work. I took the same care on my Honda's as you do your Detroit's. As for blocking I had a standing rule in my shop that a vehicle was to be safety stands under it or they were given their final paycheck. Never had anyone injured in the 20 years I had my shop.

[@stanpatterson5033]

@@rm742 I've seen Detroits in heavy truck applications that turned 2700, 2800 rip 'em's and lived to tell the tale. Not good to let them freespool that high, though. Under a load for short periods, they can handle it. 2400 rpm all day long, if they have good oil and good cooling.

[@timgraves5498]

I had my 8v71 set at 2450 ran it for 8 years like that. It ran 82 mph and at 2450 it did better on hill climbing. I needed that amount of rpm with the 4 speed manual transmission

[@edwinhsingmaster9135]

In college shop, if you were ever under a car, not fully supported on stands, you were expelled! .

[@kcbeerslinger]

I am amazed whenever you tear into a motor in this bad of shape that it would still start up and run.

[@BusGreaseMonkey]

And it drove up the hill!

[@belowme4927]

THANK GOD YOUR DAUGHTER KNOWS SOME WONDERFUL HONEST MECHANICS THAT CAN FIX HER BUS PROPERLY

[@ShainAndrews]

Maybe thank the daughter? Pretty sure your god had nothing to do with it.

[@MrTebo79]

Unbelievable, I know what it's like to deal with mechanics who don't know anything more than to guess and who in the end do very bad jobs and leave the bus worse. glad he was able to find you guys. Greetings from 🇨🇷

[@michaelfinney2160]

Such a beautiful motor coach to have such major engine problems. I feel confident you guys can make it right !

[@irongoatrocky2343]

​ @Shain Andrews its mentality like yours that caused the issues this thing has to begin with!

[@craigroberson8757]

That head moved all over the place prior to tightening. The good news is how well that will run once you get done with it. I never cease to be amazed st the number of mechanics that are completely operating above their level of competency.

[@monkeywentbananas]

Can't wait to see the rest of this engine rebuild!

[@TrimeshSZ]

I've always been really impressed with those 8V71 engines - a few years ago I was helping one of my friends rebuild several of them When we tore them down, they were all in horrible internal condition and had obviously been abused and neglected. But all three of them still ran - even the one that had a hole in one of the pistons!

[@siaripop7]

Scott I've seen some additional help around the shop and thought it might be interesting to know their names and how they view working on buses and learning from the Master Grease Monkey.

[@justfun985]

Bought a 2003 RV with a c 11 cummins. I have it in to work on the loose steering. Thanks to you guys I figure its tie rod ends replacement and the steering column gears adjustment minimum.

[@HuskyGamersUNITE]

Play in the steering no matter if a golf cart or a big rig will always be bad tire rods, front axle joints, or steering shaft itself. Tie rods can wear our or get damaged on rough roads, and steering shaft can wear out with a lot of very hard turning in and out of campground lots. You would be amazed how badly people treat vehicles and how bad they can become and still be driveable.

[@wsbrand]

That's a very clever way to push the liners out

[@edwarddeyojr.793]

It really is hard to find a good and honest mechanic for these detroits,,makes me wonder how good they are on the newer diesels...enjoy watching how you and Indy take care of your customers,,stay safe and block those monsters up,,,🇺🇸😍

[@TerribleTerry5]

Hello Mr. Grease Baboon, I wanted to tell you again. That you are the best mechanic on these buses that I ever seen. I like how you show everything that failed in the engine. Well take care & I hope you keep up making great videos.

[@philliphall5198]

I love working on them and setting the rack. Such a simple engine

[@Draxindustries1]

Beautiful looking bus. Great work as always but i think one thing id do is give that engine a thorough hot wash steam clean at 4% TFR. So much nicer to work on when theyre clean...

[@ThreenaddiesRexMegistus]

“If tight is good, tighter is better!” This seems to be a universal truth among the ham-fisted. I did a lot of gun work at one time and this was a constant issue and caused many problems. Can’t believe how tough those Detroit engines are to run with that sort of abuse. Those buses generally, in fact! Nice to see there’s people keeping them alive and well.

[@bassjaymi]

Hopefully the price paid for the bus was good enough because this amount of work is needed! Looking forward to hearing it run again!

[@stig7657]

Always into interesting ways to remove pistons and sleeves. thank you for sharing your knowledge. luvit

[@MA-wo3fb]

If I was in your place I would remove the last two main bearing caps just to make sure there a no cracks on the bock on the bolt hole, it was very common on the used core, did that engine had the rear stabilizer on the two last mains?

[@kenmatch8303]

That little popped out piece of casting looks like from inside the bell housing!. Back inside of air compressor or accessory drives.

[@bradlewellen7461]

Well thks to the poor repairs on the motor it looks like once you've done thr repairs your daughter's gonna gave a great bus. Keep up the great work.

[@danielsteward5090]

If you were in Ohio I'd send you to my grandfather's diesel shop in Youngstown. Or Miami Florida area to Terrill machine. Or RPM Diesel in Ft, Lauderdale, by the big Yacht shops on marina mile. Best Diesel shops that I know of.

[@rk-ec7kx]

I love these old buses with the detroits in them.

[@waynep343]

How about having your machine shop friend take a piece of plastic just slightly thinner than a rod cap. In a U shape. That when you pull a rod cap. You can put the U shaped plastic over the crank pin and rod bolts that is just slighly narrower than the big end of the rod so it holds the rod bearing in. So you can push up on that while doing the final. Push of the rod and sleeve out to reduce any chance of a rod bolt striking a crank journal. Or use threaded rods of plastic. Those could be used to install the piston, rod and sleeve without dropping the upper rod bearing too

[@GNX157]

How tempted are you to just pull the engine all the way out and give it a full going over?

[@woog74]

Wow beautiful bus for your daughter.

[@hawkeyemarine]

Good job, what about the guy over on Murfreesboro Road downtown.

[@wernerdanler2742]

I totally lost it when you showed that gasket that was not lined up with the hole. "Whaat, no way!" Lol This thing has been so abused, and it still ran! I hope you got it cheap Who knows what else is wrong with the bus.

[@BusGreaseMonkey]

The gasket was 50% right or 50% wrong depending in how you look at it. ;)

[@wernerdanler2742]

@Bus Grease Stevie Wonder must have worked on it with no brail. 😆

[@jordan38r]

wow i havent had my hands on a detroit diesel in a long time. worked at reman central for 20 years before it was shut down. ive done a lot failure analysis on 53's, 71's, and 92's. always hated the 71 cause of the tight liner fit for cooling and could be a real bear to remove on a failed engine.

[@noelmcgarry456]

Great to see you guys doing engine strip down nothing worse than cleaning up someone else stuff up and more workmanship

[@MWestern-m4g]

Hey! Lot of grunting for a young man taking off that oil drain plug!!! 😁

[@thatdave86]

Have you found an easy way to simply extract the engine out of the buses then pull them down ?some form of engine frame carrier that you could design,and access panels built in the bus rear end .

[@jamesallen712]

Good looking coach. With the state of the engine why didnt you pull it out to rebuild it?

[@tizio000]

You're simply the best!

[@iceman9678]

Nice work and great video!

[@justfun985]

What made that valve so brittle? I have never seen one shatter like that (not that I have seen that many). Bend and break yea. Wrong valve used? I hate mystery metal that you found in the oil. Make me wonder when it will bite you on the behind.

[@stefanm67]

Another great video guys. I do love your content. Thank you.

[@alekjuskevice]

Sometimes valves will break like that when the clearance is adjusted to tight. I wonder if that was the cause? The valve seats are so hard that they usually just need to be Re ground, if that, and a new valve lapped in by hand, that’s how I always did it at least. Not that you don’t already know all of this.

[@jamestsmith4500]

My guess on the busted out bottom of a bolt hole is someone had some trash or fluid in a head bolt hole. Checking the bottom of every head bolt hole and every bolt hole with a coat hanger wire or welding rod will find it (Maybe) I would find another block until you can find where that broken piece is from. Don't ask me how I know. (someone sabotaged one of my head bolt holes. I had to have the piece welded back in). (aluminum block)

[@peterbeyer5755]

You can get make a little tin with a few drain holes on a stick to capture the drain plug if it slips trough your fingers, it saves having to fish it out of the oil.

[@BusGreaseMonkey]

Magnet fishing is easy

[@danielsteward5090]

Wow. It's definitely time for new pistons and liners with the new heads.

[@andylowe2725]

I am curious if this engine is all back together now?

[@backyardbasher]

The outro was awesome ❤

[@artnickel1664]

Could the last rebuilder put wrong rings in top groove on pistons?

[@zachadams5685]

I have that same piece of casting on my 6v92t I found in the air box clover on passenger side

[@shaneharrison4775]

Beautiful looking bus on the outside but I cant believe someone would halfassed that engine like that. But when it's done it will be a powerhouse I'm sure.

[@michaelwilkinson9159]

Many years ago my father was a mechanic who worked on coaches (without many of the tools available today). In the workshops he was employed in there was always a 'pit' so that the coach could be driven over and then work underneath could be carried out more easily - standing up rather than lying on your back. Why don't you have a pit ?

[@MountainDreaming]

He has a physical disability and can't work with his arms over his head without excruciating pain, so no pit...

[@freemanwaters2506]

The ubiquitous nature of incompetent and inferior workmanship these days makes it extremely difficult to keep the cynicism at bay. Why do people get involved in jobs they have zero interest in performing? BGM, this will be a very nice bus for your daughter when you finish correcting all of the shoddy work!

[@wallacegrommet9343]

People like having a job, but not doing the job

[@1982MCI]

@@wallacegrommet9343 actually most anymore don’t like the job part at all and only tolerate it in order to grab the paycheck each week!

[@Doitgood52]

You guys need a service pit real bad!😮

[@jackpatteeuw9244]

Glad to see more wrenching and less test driving. I most have seen you local downtown a couple dozen times.

[@GNX157]

I skip and FF every time they leave for a test drive. It’s totally not needed for the video and they must do it for some systemic youtube reason, algorithm, or for something to do with ads and making money. I don’t think it applies here, but I thought I’d read there needing to be a minimum video time length for monetization. In any event, I just FF through it and the end music.

[@DrinkWhiskeyRaiseHell]

Who forces you to watch?

[@BusGreaseMonkey]

Some people like to hear the engine, see the improvements or if there are still issues to work through etc. plus a little time spent with the owners.

[@stig7657]

@@BusGreaseMonkey I am one of those people, it's always interesting getting the owners reaction to the changes in the driveability of the bus.

[@GNX157]

@Simr Khera I like the hear it but the test drive thru town is a waste of time when you’ve watched dozens of videos, hence the FF to the end or till they’re back in the shop. The channel doesn’t want to take the time to edit that down into a smaller chunk, so I do it myself.

[@edwinhsingmaster9135]

You guys need a fixture to R&I cylinder heads for your picker.

[@Aldoleapold]

Alpine green, my fav color

[@philhermetic]

the "overhaul" that engine has just had was a waste of time and money! What stops the ends of the piston rings getting trapped in the ports? are they pegged like a two stroke to stop the rings from turning so that the ends are always positioned on the webs between the ports? Phil, UK

[@krankie49]

I lost a friend a couple of months back when a jack failed while he was under a bus. Please block things properly.

[@BusGreaseMonkey]

There is nothing not blocked or supported.

[@timgraves5498]

At this video they are not under the bus it’s on All 8 wheels. I have seen Scott and his crew work many times they do take every safety measure possible to make a bus stable while working under it. I have known people that had a bus fall on them it’s dangerous but danger can be taken out of the process and Scott and his crew takes no chances on a job not being safe and blocked up properly. Sorry for the loss of your friend

[@Chokechain1111]

You should have told your buddy that

[@krankie49]

@@Chokechain1111 Complacency sets in ...

[@transmaster]

2 cycle Diesels are so interesting.

[@rogerreames7079]

Is the mci 7 for sale. Have you got rid of it

[@mojo68mitch]

Unreal how many hacks out there callin themselves mechanics. After u guys are done with it gonna be an amazing bus. That piece of iron you found would bug the hell out of me.

[@petersmith7140]

The machine shop is closed as in gone out of business?

[@BusGreaseMonkey]

Yes no longer in business

[@philliphall5198]

It’s hell now finding a good machine shop who even knows how to rework a DD head or check line bore

[@kenore4003]

In a throw away society a place that machines engine parts and remans components has a hard time staying alive.

[@petersmith7140]

@@BusGreaseMonkey Thats too bad

[@davidbarnsley8486]

You have to feel a bit sorry for the guy you bought the bus from Wasting money on a head rebuild that failed but he really needed a full engine rebuild instead Good for you guys 👍👍

[@just_some_internet_guy]

I assume that is you singing? Incredible music! Do you have a band?

[@BusGreaseMonkey]

That is the very talented and handsome Tom Feller”

[@avioncamper]

Who ever over tightened the oil plug needs a whooping.

[@MWestern-m4g]

with a 1 1/2 by 3 1/2

[@MWestern-m4g]

Millennial? Your Father used to "talk" to you? Luckey

[@avioncamper]

@@MWestern-m4g I'm 56.

[@MWestern-m4g]

@@avioncamper OH my-- I AM old!!!!!!! 2x4 wood.

[@18robsmith]

@@MWestern-m4g Light weight - go straight to the 8x4.

[@philliphall5198]

Wish I had a dallor for all the DD I’ve overhauled in last 57 years

[@michaelwilder9231]

A Bus for Christmas,sweet gift from Santa,BGM.

[@DonRRicks]

We have a term in East Texas for what the “mechanics” did to that engine. “Piss poor work.” Scott, I have every confidence that you and Tyler will make this right. But dang it, this is pathetic Edited to add I broke my 35-40 year old Craftsman 1/2” brakeover bar on Friday. Not confident about the lifetime warranty, so I’m thinking about the Harbor Freight $49 pro. Any thoughts on their tools?

[@ShainAndrews]

The rest of the US uses the same term for all work sourced from Tejus.

[@jerrybrooks870]

I've broken Craftsman, Ultra Last (Auto Zone brand), Ace hardware, and a few other brands of 1/2" break over bars. I got a Harbor Freight 1/2" break over bar a few of years ago and haven't broken it yet, and it's from the Pittsburgh line of tools. I think you'll be quite happy with that one.

[@DonRRicks]

If are attempting to insult Texas, get the spelling correct. It’s “Tejas”

[@ShainAndrews]

@@DonRRicks Turdass.

[@GinosGarageUSA]

Hmm interesting, does not seem like the head fix was done very well, possibly even contributed to its ultimate failure with the fuel dilution. Crazy as the previous owner probably paid alot of money to have that head work done. Well its in good hands and those kids will have a good runner when you guys are done. Nice with all that help around!

[@BusGreaseMonkey]

Not well

[@donaldcook6997]

been on motorcyles too long and missed out on the NEW stuff... very first time I saw a diesel that had valves.. did not know they re invented the diesel engine😂😂😂

[@peterbeyer5755]

Nothing gets past the Bus Grease Monkey, every major and minor issue is diagnosed, I hope this bus gives the new owner years of hassle free service.

[@craigsowers8456]

WOW ... in a single word: CARNAGE

[@whotknots]

Scott while you don't often openly say so when such circumstances arise the appalling condition that motor was in seems to suggest it wasn't properly examined after overheating much less properly repaired. A trained mechanic is a trained investigator and you are obviously exceptionally good at what you do. So it would not be difficult for you to conclude that either the former owner was a 'back yard tinker' who thought they had skills they clearly did not as evidenced by your comment of "I don't know why they didn't rebuild it when they had it apart" or, they were misled by someone who claimed to have skills they did not. Numerous indicators like excessive tension on the head bolts and drain plug for the engine oil sump along with all the 'rough as guts' make-do repairs clearly corroborate this. It is also implicit that at least one head was removed and when the extent of the damage was realized it was decided to 'get it running and sell it' so the relevant head was 'slapped on again' with minimum attention to normal procedures a professional would observe under any circumstances. The fact that not even the failed valve was replaced combined with all the other indicators suggest the same obviously unskilled/unprofessional source performed the bulk of recent work on the engine prior to you purchasing the bus and could not have been aware it would be you who did so. It is probably a reasonable presumption that the former owner already knew or learned enough about you by interaction during the process of purchasing the bus to appreciate you would eventually discover the truth and it would be publicized on your channel. So if the previous owner was aware of your skills they would not knowingly sell the bus to you or mislead you in the process for that reason alone but it might not be too difficult to establish a few facts in that regard either. I hope you bought the bus for a price that reflected the amount of work required to bring it up to a mechanical standard you would consider acceptable.

[@BusGreaseMonkey]

Yes we bought it at the extremely discounted “as is” price.

[@lloydrobinson7081]

keep the clips coming

[@bill8582]

Scott, I have found a 1994 MCI 40 foot conversion. It has a 6V92 in it, seems like a lot of bus for a 6 or am I wrong on that. Is this something that you could shoehorn a series 60 and matching transmission in? Would the rearend have to be changed as well? What would be the cost for something like that?

[@hotpuppy1]

6x92=552; 8x71=568. That is only 16 cu in. difference. The 6v92 is a pretty good engine with wet liners so overheating possibility is less AND they put turbos on them for more power.

[@methanial73]

I wonder if a little marvel mystery oil would've kept those rings free?

[@christopherrasmussen8718]

I be pulling that engine out. Metal is loose. No telling. Fresh rebuild I say. Sorry in frame. That hunk of steel.

[@DrinkWhiskeyRaiseHell]

Were you trying to write a haiku?

[@BusGreaseMonkey]

Especially since we are doing an in-frame rebuild it makes even less sense

[@delorispoindexter5663]

That engine said mmm.yummy that valve tast good

[@petrhoward]

That piston crown will buff out, lol

[@joemaser9122]

Those fire ring's aren't stuck they have been so hot that they collapsed I have seen them welded to the piston. Too bad since you have to buy the parts anyway you could turbo it and make it into a 400hp engine without a lot more investment

[@BusGreaseMonkey]

Any clue what that chunk from the pan is?

[@joemaser9122]

When you get a chance please call me

[@greyjay9202]

As I've said before, it is dismaying to see so much shoddy workmanship coming out of other shops. This problem crops up frequently in light truck and automotive repair shops too. According to the FAA and the NTSB, it also occurs occasionally in aircraft repair and maintenance facilities. Really shocking.

[@doesthisfacemakemelooklike535]

literally saved this bus IMO.....

[@ez1913]

It may be time to invest in some of that vintage machine shop equipment, out of necessity.

[@BusGreaseMonkey]

kzbin.info/www/bejne/hHfVeZ6Hht6hZrs

[@MWestern-m4g]

The piston has termites

[@andrewsidles7672]

Hi Scott

[@BobSweeney58]

Thought your daughter had a bus that you were fixing (at the bottom of the hill, on the pad)?

[@BusGreaseMonkey]

Upgrade

[@18robsmith]

@@BusGreaseMonkey Scott's doing it for his grandchild ;-)

[@luviskol]

A lady likes to have options when she's going out and about

[@memadmax69]

Just JB weld it, it'll be fine. ^.^

[@georgekaplan6451]

The mis-aligned gasket says it all really about the quality of workmanship.

[@danielthechskid]

The sad part is I know where an MC6 or 7 is that has been just sitting for 10 years, not sure who the owner is though.

[@SuperMAZ007]

Maybe it's time to invest into a head grinding machine?

[@danielsteward5090]

I have the tools to pull those liners out without using the pistons to push it up.

[@douglasburford8452]

Back in the day, we had Detroit heads welded, usually to very good effect.

[@jamest.5001]

I love Detroit diesel, the old 2t, engines, I'd throw a couple turbos on her, with intercooler, a huge one, get at least 1-1.5bar boost, and deck the block slightly,. Try to raise the compression a bit,

[@Imwright720]

Owning a bus is like owning 3 boats. One giant black hole for your money.

[@jhenderson3087]

Can you adopt me and buy me a bus? 😊

[@H4rleyBoy]

You certainly can use a torque wrench to loosen bolts, it is not the best idea. Torque wrenches are precision measuring instruments, using them to loosen bolts is not in line with that purpose. You end up stressing the tool when it is used as a breaker bar, and you often need excessive force to loosen bolts.

[@BusGreaseMonkey]

It’s a torque gauge. Rated up to 700 ft lbs. we tested something that was supposed to be torqued recently at 90-100. Yes they certainly can be used to double check someone’s work.

[@mikebudney9892]

Detroits don’t leak oil,,,, they sweat horsepower!

[@dannygoin6552]

🇺🇸🇺🇸🇺🇸🍻🍻🍻☕️☕️☕️👍👍👍🥃🥃🥃👀👀👀🇺🇸🇺🇸🇺🇸

[@andrewhorsburgh2549]

Hope you got that for the right price cause the engine is a dog. Don't know about the rest of the running gear.

[@brianferguson6278]

So purchased at "As is Discount", but relativity is for they non-mechanic that motor rebuild is what $20,000.00 bill??

[@BusWithUs.]

Yeah didn't look pretty when I saw the parts on the floor!

[@MWestern-m4g]

Tiger Tite

[@donw3912]

Whoever put that engine together last did not do a good job in the slightest.

[@artnickel1664]

The people who last worked on that bus should not be “mechanics” anywhere.