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Foretravel Motorhome Forums => Foretravel Discussions => Topic started by: Vebb on January 11, 2025, 10:23:52 pm

Title: Detroit 6V92 Mechanic
Post by: Vebb on January 11, 2025, 10:23:52 pm
Greetings, can anyone recommend a mechanic EXPERIENCED with Detroit engines? DD 6V92 Dec II? Having difficulty finding someone in Western PA, willing to travel.
Title: Re: Detroit 6V92 Mechanic
Post by: Pierce & Gaylie Stewart on January 11, 2025, 11:36:16 pm
What is wrong with it? Fire Dept, marine yard, independent bus company.  YouTube's Bus Monkey would be a good source. He may not be that far away and charges much less than a big shop. https://www.youtube.com/@BusGreaseMonkey

Pierce
Title: Re: Detroit 6V92 Mechanic
Post by: Vebb on January 11, 2025, 11:51:08 pm
I have an email out to him, he did respond but was wondering how tight it was to get access to I sent some pics I haven't heard anything back. I'm guessing he isn't hurting for work.. I've called quite a few places and just keep coming up empty. Started calling into Ohio no luck either. It's wild!
Title: Re: Detroit 6V92 Mechanic
Post by: Vebb on January 11, 2025, 11:59:41 pm
Sorry- to answer your first question hard to start, losing a gallon of oil every two hours, overheating on hills. My husband and brother are mechanically inclined and have replaced everything that they can. Just had the radiator re-cored too.
Title: Re: Detroit 6V92 Mechanic
Post by: Pierce & Gaylie Stewart on January 12, 2025, 01:20:30 am
Overheating can be a big problem with any diesel with wet liners like the 6V92TA or an 8.3 Cummins, etc. The override switch on the instrument panel is frequently used if the DDEC has gone into it's 30 second protective mode but this may cause damage or even warp the block making it necessary to buy another engine.

Any coolant in the oil?

Here is a PDF of the 6V92TA engine: scavange ports detroit diesel 6V92TA - Google Search (https://www.google.com/search?q=scavange+ports+detroit+diesel+6V92TA&oq=scavange+ports+detroit+diesel+6V92TA&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIJCAEQIRgKGKABMgkIAhAhGAoYoAEyCQgDECEYChigATIJCAQQIRgKGKABMgkIBRAhGAoYoAEyBwgGECEYjwIyBwgHECEYjwLSAQkyNDgyMGoxajeoAgCwAgA&sourceid=chrome&ie=UTF-8)  You can see all the part in the illustrations. The pistons and cylinder may be inspected  a borescope/endoscope via the scavage ports. Check online for articles on how to do it.

If you do have damage, the engine can be overhauled inframe (without removing it) in an old barn with normal tools. Unlike dry liners, the wet liners can be removed with a home made tool that goes across the liner and slightly into the intake ports. The correct liner height is adjustable with shims so no maching is needed. The O rings are installed only after the correct height is found.

Parts can be ordered directly from China to save time and money. As I remember, there are over 30 companies in China that manufacurer piston liner kits for our Detroit 2 cycles. All the other parts also. Alibaba is one source.

Scopes for the inspection are cheap. Nice to have a high resolution model that is plug and play with a laptop.

Removing the cylinder heads requires two people as they are cast iron and heavy.

Using a multigrade engine oil or high ash oil can damage the pistons/rings

Pierce
Title: Re: Detroit 6V92 Mechanic
Post by: stump on January 12, 2025, 08:21:01 am
These guys are 2 stroke experts
Leid Diesel Services
(717) 776-7725

 Leid Diesel - Google Search (https://g.co/kgs/atF6wHC)
Title: Re: Detroit 6V92 Mechanic
Post by: Vebb on January 12, 2025, 08:31:17 am
Overheating can be a big problem with any diesel with wet liners like the 6V92TA or an 8.3 Cummins, etc. The override switch on the instrument panel is frequently used if the DDEC has gone into it's 30 second protective mode but this may cause damage or even warp the block making it necessary to buy another engine.

Any coolant in the oil?

Here is a PDF of the 6V92TA engine: scavange ports detroit diesel 6V92TA - Google Search (https://www.google.com/search?q=scavange+ports+detroit+diesel+6V92TA&oq=scavange+ports+detroit+diesel+6V92TA&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIJCAEQIRgKGKABMgkIAhAhGAoYoAEyCQgDECEYChigATIJCAQQIRgKGKABMgkIBRAhGAoYoAEyBwgGECEYjwIyBwgHECEYjwLSAQkyNDgyMGoxajeoAgCwAgA&sourceid=chrome&ie=UTF-8)  You can see all the part in the illustrations. The pistons and cylinder may be inspected  a borescope/endoscope via the scavage ports. Check online for articles on how to do it.

If you do have damage, the engine can be overhauled inframe (without removing it) in an old barn with normal tools. Unlike dry liners, the wet liners can be removed with a home made tool that goes across the liner and slightly into the intake ports. The correct liner height is adjustable with shims so no maching is needed. The O rings are installed only after the correct height is found.

Parts can be ordered directly from China to save time and money. As I remember, there are over 30 companies in China that manufacurer piston liner kits for our Detroit 2 cycles. All the other parts also. Alibaba is one source.

Scopes for the inspection are cheap. Nice to have a high resolution model that is plug and play with a laptop.

Removing the cylinder heads requires two people as they are cast iron and heavy.

Using a multigrade engine oil or high ash oil can damage the pistons/rings

Pierce
Thank you for your input! I agree with you- I think my husband could do it himself at home but he isn't convinced..yet. It's been issue after issue since we brought it home spring of 2021. We really had no idea what a treasure it was that we were buying OR what we were getting into mechanically but he has figured things out- if not we'd never have made it out of the driveway!
Title: Re: Detroit 6V92 Mechanic
Post by: Vebb on January 12, 2025, 08:33:38 am
These guys are 2 stroke experts
Leid Diesel Services
(717) 776-7725

 Leid Diesel - Google Search (https://g.co/kgs/atF6wHC)
Thank you I will try them tomorrow!
Title: Re: Detroit 6V92 Mechanic
Post by: stump on January 12, 2025, 10:07:38 am
When the engine is running is it smoking badly?
Is it leaking oil out where it is dripping on the ground?
Is the exhaust pipe wet with oil?
Title: Re: Detroit 6V92 Mechanic
Post by: Vebb on January 12, 2025, 11:07:00 am
When the engine is running is it smoking badly?
Is it leaking oil out where it is dripping on the ground?
Is the exhaust pipe wet with oil?
It smokes baldy when it is first started
No
No

It leaks oil out of air box drain into catch can.
Title: Re: Detroit 6V92 Mechanic
Post by: erniee on January 12, 2025, 11:22:50 am
Stewart and Stevenson work on detroits
Title: Re: Detroit 6V92 Mechanic
Post by: Pierce & Gaylie Stewart on January 12, 2025, 11:34:39 am
Turbo failure with oil going into the engine burning pistons. With the turbo mounted up top only a couple of inches from the bed, cool down is mandatory after climbing grades or any hard pull to avoid oil coking. Idle at 1000 rpm for several minutes. Oil temperature comes down slower than coolant temp. I saw the results of an 8.3 Cummins lose a turbo and frying two pistons.

A couple of members wanted to know if they could get rid of the big air cleaner and just use a screen or small filter. Easy way to get the engine dusted so much less compression and harder to start. They wanted more power.

Our 6V92TAs are hard to start in cold weather as Foretravel used a thermostat housing heater instead of a block heater. This installation is totally ineffective. The normal location is down on the block under the AC compressor mount. This is how Wanderlodge and all big rigs do it. Plus, our turbo engines have a couple points less compression ratio compared to 71/92 series non-turbo 2 cycles. A variety of pistons are available. If you want instant starts, an external heater is needed. Pretty easy to install as the block and head have threaded plugs. Air leaks in the block diesel hand pump and bad gaskets can let air in and make starting hard.

In Detroit classes, the instructors said to keep idle time as short as possible so we had a 1000 rpm switch. After pumping at a fire, the normal 600 rpm idle had too little oil pressure plus the rings don't get lubricated well in this case. Our engines don't have block oil squirters.

Is the coolant milky or smell of oil? 

Wonder if someone used ether on a warm engine? Easy to break piston rings that way.

I've operated and owned Detroit 2 cycles since the late 1960's. My fire department repowered trucks with Hall-Scotts to 8V-71s and they were flawless. Started in about a tenth of a second. My Buffalo bus was also 8V71 powered and never gave any trouble in all the years I owned it. Unless they have poor maintenance, they should be trouble free.

Here is an ebay overhaul kit for under $2000: DETROIT DIESEL 692 ENGINE OVERHAUL KIT DETROIT DIESEL 692 INFRAME KIT 6-92 |... (https://www.ebay.com/itm/262689659248?_skw=detroit+diesel+6V92TA+piston+liners&itmmeta=01JHDMQGEB2YEF1YZ5NPGZPA57&hash=item3d29861970:g:I78AAOSwBLlVLsve&itmprp=enc%3AAQAJAAAA4HoV3kP08IDx%2BKZ9MfhVJKkEGkYtRdgH7Yot8oBeRw%2BMqEScE3VBrA9AnM6vLdEykN%2FhYSe2JHigB7dgtp04IvezKP1nEo2C7A58r7D2u%2Bel600ix1U7r9O90w44N2G95kCBZflqSTvUmGWSfrYZWEcH04nf5p1zfVNU7Ei96KtqX4nNUH8mY1K2XWU7TcQpSnA%2Bz2Pa4QGTPcbieekU8eHkDxQlKiW1Wo4ILDrVLC7VAm3VD886L7%2FCnwxHKvd3x2omNiJ%2BPr%2B0dAC66tFFg26SOP2rd094CVkJ40qfJGil%7Ctkp%3ABk9SR6iH3rSLZQ)  Make sure it's for an aftercooled 8V92TA  Intercooled Detroit 2 cycle take a different set of pistons. Possibly a different compression ratio.

Rack rate Detroit engine prices: Detroit Diesel 6V92 Turbo Engine Rebuild, Overhaul, Inframe Kit (https://dieselpro.com/detroit-diesel-parts/6v92-engine-turbo2/engine-overhaul-inframe-repair-kit.html)  The inspection port gaskets are in window #9. This is where the endoscope goes for inspection.

YouTube video for wet cylinder liner installation: https://www.youtube.com/results?search_query=how+to+install+detroit+diesel+cylinder+liners

Pierce
Title: Re: Detroit 6V92 Mechanic
Post by: Pierce & Gaylie Stewart on January 12, 2025, 12:02:15 pm
Preparing you for sticker shock, it's not unusual to receive a bill for $30,000 for any internal engine work on an RV. So, it really pays to either do the work yourself or find someone retired with the experience to help with the overhaul if that's what is needed.

There is no "black art" to working on one of these engines. There is no "running the rack" on the DDEC electronic engines so anyone with good mechanical experience can do it. Plenty of YouTube videos to guide even a sharp newbie (to the engine). Even running the rack is no big deal on the old mechanical engines. If you can search for a YouTube video, you can do it.

It could be something easy like a plugged breather so make sure what the problem is before spending the big money.

Pierce
Title: Re: Detroit 6V92 Mechanic
Post by: Vebb on January 12, 2025, 02:25:07 pm
Preparing you for sticker shock, it's not unusual to receive a bill for $30,000 for any internal engine work on an RV. So, it really pays to either do the work yourself or find someone retired with the experience to help with the overhaul if that's what is needed.

There is no "black art" to working on one of these engines. There is no "running the rack" on the DDEC electronic engines so anyone with good mechanical experience can do it. Plenty of YouTube videos to guide even a sharp newbie (to the engine). Even running the rack is no big deal on the old mechanical engines. If you can search for a YouTube video, you can do it.

It could be something easy like a plugged breather so make sure what the problem is before spending the big money.

Pierce
The sticker shock ship has sailed I'm sticker stunned. I'm hoping your tutoring will give him the confidence he needs to tackle this because that seems to be the only way we aren't going to end up upside down. If it was a black art it sounds like you're the magician! 🪄✨ Thank you so much for sharing your knowledge!
Title: Re: Detroit 6V92 Mechanic
Post by: Pierce & Gaylie Stewart on January 12, 2025, 08:52:30 pm
I think the first thing you have to do is figure out where the oil is going. Is it burning it because of piston ring damage or is it burning it because of turbo failure or.... You have the 300hp version so no side radiator and hydraulics. Overheating? Is it overheating in normal driving or just on the long grades? Winter or summer or both? I never let ours go over 200 degrees before I shift down and if that does not do the trick, I back off the throttle until it cools.

The bus guy on YouTube is the real expert. He has worked on hundreds of buses and motorhomes with all different kinds of engines. I would put a list together of all of your symptoms including when they happen, when did they start, etc, etc. It would be good to pay him for an hour of his time to do his little grey cells thing. He can save many thousands and is honest. Too many shops are lookig at your wallet when they shake hands. They have a "good reason" why their parts are better than others, etc, etc. I think he even allows owners to work along with him to save hours.

Have your husband give me a call or PM with a good time to give you guys a ring.

Best, Pierce
Title: Re: Detroit 6V92 Mechanic
Post by: Lon and Cheryl on January 13, 2025, 09:53:35 am
I also would suggest the BusGreaseMonkey found on YouTube.
Recently he has been traveling to St Louis to do a in yacht rebuild on one of the two DD 8v92 engines in a Hatteras.
I thought I heard him say he was charging $1500 per day. I don't know if that includes his travel expenses but that's a good rate for his efforts.
He seems to try very hard to keep repair costs down and fix things so they are actually fixed. He does not rush to replace parts when he can rebuild a part.
I also enjoy watching him teach his Son the business without yelling at him or belittling him if he makes a mistake, he is a very good teacher. 
Title: Re: Detroit 6V92 Mechanic
Post by: Pierce & Gaylie Stewart on January 13, 2025, 10:48:05 am
I thought I heard him say he charged $50/hr in his shop but that may be old. $1500 could be when he travels for all expenses.

I can still see the Setra (think it was a Setra) bus in San Francisco with it's flat air cooled diesel. It was idling when I spoke to the driver. He said the shop could swap engines in 15 to 20 minutes as there were only four bolts and all the other connections were modular. It had air jacks so the bus could be raised so the flat engine could roll out without removing the bumper. The cooling fan was mounted above and blew down on the engine so didn't have to be removed for maintenance. When idling, the fan didn't even run. Rear wheels also turned to make corners, get out of parking places.

P
Title: Re: Detroit 6V92 Mechanic
Post by: steve on January 13, 2025, 10:55:08 am
Last info form the BGM site:

2024 prices

No travel appointments are available in 2024

We are not open for business to the general public. Only Patreon members are eligible to schedule services at our homestead in TN Bus Grease Monkey | Creating Videos | Patreon (https://www.patreon.com/busgreasemonkey)

Hourly shop labor rates (Centerville TN area)

$160/hr with client helping, working, learning
$175/hr working without client's physical assistance.

Minimum 2 billable hrs per day (includes waiting on parts days) (weekends excluded) m-f

$500 non refundable service call retainer required

30a electrical hookup provided in camping fee $25 per night

We also offer camping sites where you can work on your own bus. $165 per day includes usage of our tools and up to one hour a day of assistance. Engine rebuilds or any extensive maintenance can be performed here. This is a great option for full time rv'ers to accomplish maintenance themselves. 30a electric, water included and remote dump station access.
Title: Re: Detroit 6V92 Mechanic
Post by: Pierce & Gaylie Stewart on January 13, 2025, 11:33:21 am
Great info Steve!! The $165/day seems like a great deal in the last paragraph. I see he has made lots of improvements to his shop and road up to his place. Not to make the Indian ride the buffalo but I wonder if the $165 includes the camping fee?

I only have time for an occasional view but it's scary the shape some coaches are in when brought to his shop.

Pierce
Title: Re: Detroit 6V92 Mechanic
Post by: John44 on January 15, 2025, 01:24:00 pm
Sent you a message about helping,did you see it?
Title: Re: Detroit 6V92 Mechanic
Post by: Protech Racing on January 15, 2025, 07:14:57 pm
I'm about 2 hrs. From there .
Title: Re: Detroit 6V92 Mechanic
Post by: Pierce & Gaylie Stewart on January 15, 2025, 11:54:02 pm
OK, so here is the deal. When they bought the coach, the air cleaner element had been replaced with a NAPA brand but it turns out that the element was smaller and dropped down several inches. The turbo had leaves in it and the blades were damaged. They have a second engine that came from a burned Foretravel. The turbo was exchanged and while it gave a little better boost, the starting problem and overheating was still there. The little oil tank is full after driving a couple of hours.

The engine is dusted in my opinion and needs to be rebuilt but the other engine only has 30K since new. He is trying to figure the best way to R&R. I would remove the Fiberglas back bumper, drill out the rivets on the cross member, remove it and slide out the engine with a forklift and put the replacement in. The coach drives so the best thing would be to do the R&R on flat concrete. Too bad as the engine only has 60K since new.

The person installing the air filter should have been aware but the big mistake was made by Foretravel is in the location right behind the rear wheels where everything that comes off the tires goes directly into the air intake. This is exactly the same as ours and while it was changed two years later, that's no excuse for the incredible lack of any kind of ability in designing the intake system. To the guy that thought up this arrangement, STUPID, STUPID, STUPID.

It's bad for a Cummins but twice as bad for a Detroit 2 cycle as they use twice as much air as the Cummins so twice as much dirt will be sucked in per mile. And to top that off, any water coming off the rear tires in the rain will be sucked in and saturate the aircleaner causing it to crush or partially crush as ours did.  How many engines have been lost because of this design?

Nice if a member could give him a few hours help if the location is convenient.

Pierce

Title: Re: Detroit 6V92 Mechanic
Post by: John44 on January 16, 2025, 04:28:26 am
I sent them a PM offering just that but they have not replied,trying to help but they have been silent for days.
Title: Re: Detroit 6V92 Mechanic
Post by: Protech Racing on January 16, 2025, 08:38:03 am
I can maybe help also.
 I don't have room at my shop tho. 
Title: Re: Detroit 6V92 Mechanic
Post by: Vebb on January 17, 2025, 06:14:08 am
I sent them a PM offering just that but they have not replied,trying to help but they have been silent for days.
I see it now John I had to take a hiatus, just sent you a PM back!
Title: Re: Detroit 6V92 Mechanic
Post by: Vebb on January 17, 2025, 06:24:03 am
Thank you everyone for your offers and help! I needed to take a break for a few days so I handed over to my husband and Pierce. I now have some calls out to a few shops for estimates. We got a few recommendations in PA and MD so not terribly far. Regardless we're expected to be in the -10 temps next week so I don't think we'll be working on it at home- or going anywhere anytime soon. If anything comes to fruition I'll update but at a stand still for the moment.