After driving the bus for about 30 miles (we movie ever few weeks) I woke up go find antifreeze dripping out of the air box catch can on my 6v92. A good amount of coolant came out. When I recently changed the oil, I drained this can and didn't have any water in it.
After some research it sounds like a cylinder liner could be leaking...
Where do I begin?
Pull the air box covers if one is leaking it will show on the outside of the liner if the head or gasket is bad it will leak on the inside of the liner, adding a couple of pounds of air to the system helps a bunch when looking for a leak on a 92 series, do that first some times it is a simple 0-ring leaking on the after cooler or a leaking after cooler
I had to add oil to the engine to get the level up to check for milky oil. When I did, the antifreeze started dropping out of the catch can again. Curious, I opened the catch can up some more and then it was really flowing out pure coolant.
So far the oil looks clean and not milky but it's been sitting for two days.
I'll pull the air box drains and report back. Thx.
A injector tube will leak to inside of the liner too
Quote from: GnarlyBus on June 16, 2018, 08:13:48 AM
I had to add oil to the engine to get the level up to check for milky oil. When I did, the antifreeze started dropping out of the catch can again. Curious, I opened the catch can up some more and then it was really flowing out pure coolant.
So far the oil looks clean and not milky but it's been sitting for two days.
I'll pull the air box drains and report back. Thx.
if the crank journals have run with coolant/oil you could have a whole different can of worms....
Opened up the passenger side...what am I looking for exactly? Rotate the engine and watch these holes? (https://uploads.tapatalk-cdn.com/20180616/51660fd593457946fc6e6f28a62648b3.jpg)
Add a little air pressure to the system no more than 5 lbs if the liner o-ring are bad it will leak check both sides it will puddle at the bottom if one is leaking
Quote from: eagle19952 on June 16, 2018, 08:18:51 AM
if the crank journals have run with coolant/oil you could have a whole different can of worms....
Not seeing any coolant in the oil intern dipstick or other places yet. So hopefully that hasn't happened.
Quote from: luvrbus on June 16, 2018, 08:55:29 AM
Add a little air pressure to the system no more than 5 lbs if the liner o-ring are bad it will leak check both sides it will puddle at the bottom if one is leaking
Not sure how to do this. What system do I add the pressure to and where do I tie in at? I do have a mityvac hand pump, maybe I can use that?
I appreciate the help!
You can remove a plug or a gauge sender on T stat housing to pressurize the system
A little pressure to the coolant system, mimicing the operating pressure, so that any leaks will expose themselves.
Lots of leaks won't leak unless there is a little pish behind them.
A jig to fasten in somewhere with a shraeder valve, like your tires, and emphasis on A LITTLE PRESSURE...
Happy coaching!
Buswarrior
I setup a ball valve to add pressure to the system with a mityvac hand pump. It does build pressure but I can't get it up to 5 psi. After pumping, I noticed the coolant dripping out ABOVE the air holes (the coolant doesn't appear to be inside the cylinder at all, but outside) on the middle cylinder liner on the left side. Again, the bus isn't perfectly level and the left side is lower.
I've attached a video of the leak.
https://www.youtube.com/watch?v=5QK6j-w1rFo (https://www.youtube.com/watch?v=5QK6j-w1rFo)
That's a great video. Free bump to the top for someone to view that leak on his video and chime in.
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Turn engine slightly for piston to uncover ports in that cylinder and repeat.
So when did you get it hot/ overheat in past?
It is the liner seals leaking you have 2 o=rings seals above the ports on the liner in the block, that is a bummer the heads and pan need to come off and pull the liners to replace 30 bucks of o-rings, thanks for the video
While you're at it, probably should replace all cylinder liner O-rings. This is a big reason I found a bus with a 8V-71 (71's have dry cylinder liners). Good Luck, TomC
Quote from: chessie4905 on June 17, 2018, 04:59:09 AMTurn engine slightly for piston to uncover ports in that cylinder and repeat.
So when did you get it hot/ overheat in past?
We did this before we shot the video to make sure the water wasn't coming from inside the cylinder.
We triggered the engine temp shut down one of the first times we drove the bus over 3 years ago because the coolant sight glass bulb hose had a kink in it making it look full. Never ran it hot since then.
Quote from: luvrbus on June 17, 2018, 05:58:49 AM
It is the liner seals leaking you have 2 o=rings seals above the ports on the liner in the block, that is a bummer the heads and pan need to come off and pull the liners to replace 30 bucks of o-rings, thanks for the video
Ok, I've been soaking up knowledge, reading the manuals and doing my own maintenance for a few years so I would be more ready to tackle inevitable jobs like this. My bus is my home so it has to be done!
I'll be working on this project over the summer.
1. if I drain the slobber catch can (and leave it open) and make sure the coolant and oil are topped up, how crazy is the risk of driving the bus 15 miles to move it somewhere I can work on it?
2. Where exactly is the coolant coming from before it gets past the cylinder liner seal? Does that mean my head gasket is bad too?
No head gaskets will leak coolant into the oil and most of the time hydro lock a engine, there is a 2 inch water jacket around the liners at the top that is where the coolant is leaking from.
Makes no difference about the head gasket the heads come off anyways.when you go back buy good antifreeze stay away from the Walmart crap,you can drive it 15 miles as long as the drains are open and coolant is not going into the oil.You have a lot of work to do, parts are not bad around 100 bucks total plus the fluids and bearings which I would replace
Quote from: luvrbus on June 17, 2018, 09:20:10 AM
No head gaskets will leak coolant into the oil and most of the time hydro lock a engine, there is a 2 inch water jacket around the liners at the top that is where the coolant is leaking from.
Makes no difference about the head gasket the heads come off anyways.when you go back buy good antifreeze stay away from the Walmart crap,you can drive it 15 miles as long as the drains are open and coolant is not going into the oil.You have a lot of work to do, parts are not bad around 100 bucks total plus the fluids and bearings which I would replace
you don't think now is the time to measure and measure some more ?
no way i go that deep and just replace the o-rings and rod bearings...
Quote from: eagle19952 on June 17, 2018, 07:38:51 PM
you don't think now is the time to measure and measure some more ?
no way i go that deep and just replace the o-rings and rod bearings...
Yep when he gets in there no telling what he will find ,I did notice the build up on the 1 piston I could see
When you pull the sleeves, do you pull the pistons/rods first or as an assembly? I always assumed as an assembly.
Brian
Quote from: bevans6 on June 18, 2018, 08:21:46 AM
When you pull the sleeves, do you pull the pistons/rods first or as an assembly? I always assumed as an assembly.
Brian
I pull those as a assembly you can do both ways
Quote from: luvrbus on June 18, 2018, 08:30:42 AM
I pull those as a assembly you can do both ways
not without a loader :(
or a Sharpie :)
After reading the shop manual's instructions for removing the head, I have a few questions. I'm trying to visualize the project before I start it. I know this could turn into a larger more complete overhaul once I get in there and see what's up, but I'll start here.
1. Will I need to remove the turbocharger?
2. The manual didn't say anything about removing the rocker arm assemblies. Do these or the jakes need to be removed?
3. What kind of lift am I going to need to get the head lifted off the block?
4. I'm thinking of getting an air ratchet (not impact) to help make this a little less knuckle busting. Think that would help?
Thanks for all the replies!
Top mounted turbo dosen't need to be removed just the piping to the heads ,the rocker arm stands and Jake need to come off to get to the head bolts, the lift will depend on the space you will need a set of guides to re install the head,the air ratchet is going to be kinda of useless buy a impact air or one of the new cordless model,you have a liner puller ? and pull the injector to protect the tips from getting broken good luck
3/8" air ratchet, might come in handy on 8-10 bolts on a DD. :)
Going to be pulling the oil pan off too, and you'll need a torque wrench to put it all back together. If the heads are off, the pan is off, how could you resist not pulling all the liners out to change all the O-rings? And if the kits are out, how can you resist not doing new piston rings? And new rod bearings? And all of a sudden it's a complete in-frame... These things have a way of multiplying, kind of like rabbits...
I hear that, Bevans. I'm processing all this new information and considering all options. I have quite a few tools with me including a compressor, impact wrench, and torque wrench. I have the time to do the work. I want to learn how to do the work because I don't have a ton of money and prefer to do things myself.
The engine appears to me to be in good shape. When I use a coolant heater and start it up, barely a puff of smoke comes out. It does not appear to need a rebuild but it is tempting for the amount of work I'm already doing...
I'm glad I learned how to do a tune up this last winter so I have more confidence putting the head back in tune.
A coolant heater will make most start clean. How clean it starts Without any starting aid or heat will tell you more.
If you spend time on You tube, there are many videos to assist you in the task. Keep all fasteners in order or bagged or whatever to reinstall in proper location. One thing that can help you is to get a cheap notebook and document each procedure in dismantling. It will be of great value in reassembly, especially since time to reassembly will result in loss of memory where and when you did what.
That's a good tip on keeping notes. I feel like I've watched all the YouTube videos on two stroke diesels 4-5 each at this point. :) I wish there were more!
I'm wondering what kind of lift I can use to get the head off and on the block? Harbor freight sells some but I'm not sure if they'll cut it. Anybody have any reccomendations?
The H/F will work the head weighs less than 100lbs,rent one from Auto Zone is another option
Get someone competent to help lift them off. Two of us could lift off a 6-71 head.
Are you saying two people could lift the head off without a lift? That would be nice. I was thinking they were like 250 lbs or something.
I read about putting them back on and on top of using the guide shims, it seemed like it was very important to go slow to not jostle the little o-rings and shims.
Quote from: chessie4905 on June 18, 2018, 05:37:17 PMGet someone competent to help lift them off. Two of us could lift off a 6-71 head.
I weighed a 6v92 head today for shipping they weigh 121 lbs ea
Thanks luvrbus! That's good to know. I'm thinking of picking up a Kent-Moore J-22062-A Cylinder Head Lifting Fixture (couple of them available used online). That and a lift would probably make it easier and prevent damaging anything.
Quote from: GnarlyBus on June 18, 2018, 08:32:43 PM
Thanks luvrbus! That's good to know. I'm thinking of picking up a Kent-Moore J-22062-A Cylinder Head Lifting Fixture (couple of them available used online). That and a lift would probably make it easier and prevent damaging anything.
use paper matches with the red torn off to position/wedge the perimeter gasket..we used loaf pans to organize bolts...
takes 4 good sized...not banana bread sized :)
Quote from: luvrbus on June 18, 2018, 08:27:57 PM
I weighed a 6v92 head today for shipping they weigh 121 lbs ea
Oh the memories. OUCHH! :o
Quote from: Van on June 19, 2018, 01:21:33 PM
Oh the memories. OUCHH! :o
We got those on didn't we Van
Gnarly,
Not sure what your actual name is, but you seem to have a positive "can do" attitude and approach to this that is refreshing. And yet you don't sound overly zealous or naive. I can't imagine having to tear down my engine to the level you're discussing but you seem to be absolutely up to the task. I'd spend plenty of time listening to the guys on here offering you help, and ignore the ones that may just be negative. If you can get comfortable doing this you will be able to be a huge help to some of us later on down the line when we have issues. That being said, I have a genuine Detroit diesel 6v92 in frame kit for sale if you need one. I don't think it has absolutely everything you'll need but it does have 6 cylinders, liners, rings and even a cam I think?
Scott
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He dosen't need a cam only the gasket kit for your kits Scott 200 bucks and he will have gaskets left over
Quote from: Scott & Heather on June 19, 2018, 02:33:34 PM
Gnarly,
Not sure what your actual name is, but you seem to have a positive "can do" attitude and approach to this that is refreshing. And yet you don't sound overly zealous or naive. I can't imagine having to tear down my engine to the level you're discussing but you seem to be absolutely up to the task. I'd spend plenty of time listening to the guys on here offering you help, and ignore the ones that may just be negative.
I appreciate your words! I've gone through a few waves of being totally overwhelmed with the idea of taking the engine apart. When I called 6 places yesterday and asked if they work on these engines, none of them did (including Southern Oregon Diesel btw which I've seen mentioned on here). Then I got a hold of a Freight liner up in Washington that said 7-8k in labor alone (to replace the liner seals), not including parts that they weren't sure they could source.
When I told the guy I was considering doing it myself, he said "oh no, you cannot do this yourself!". When I asked why he said there were all these special tools that were needed. His reaction freaked me out a bit.
I've got a list of tools started (guide shims, liner puller, cylinder clamps, head lift attachment, etc).
The thing is for me, it's either fix it myself pretty much by myself or park it and be done. This is my home. Were in our early 30s and live on the road full time in Oregon and Arizona. I wish I had a shop to do it in. I wish I had someone to show me how to do it. I wish there were videos online teaching me the process, but I'm glad everyone here keeps responding to my posts. I'll take lots of pics and videos when I start this project in the next few weeks.
Still considering what level of rebuild I want to do. I'm prepared to get the parts I need once i can inspect the condition of the pistons and liners.
How do I know now if it needs a rebuild? Compression test? It seems to run well but I don't have much to compare it to.
Quote from: GnarlyBus on June 19, 2018, 09:08:53 PM
How do I know now if it needs a rebuild? Compression test? It seems to run well but I don't have much to compare it to.
well, were i you,
before you get to deep, pull the heads and have them inspected for cracks and warp etc. look at the valve seats.
if the head/heads are toast, look for a gooder engine... ?
Cliff, what do I do with my cam? I have no idea why I even have it. It's still sealed in its cardboard tube. Came with my coach. I do wonder if an engine swap would come out easier and cheaper in the long run. You have access to some cheap donor buses/engines that california is trying to dump because of new EPA requirements basically outlawing two strokes...that's an idea.
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Quote from: Scott & Heather on June 20, 2018, 04:12:17 AM
Cliff, what do I do with my cam? I have no idea why I even have it. It's still sealed in its cardboard tube. Came with my coach. I do wonder if an engine swap would come out easier and cheaper in the long run. You have access to some cheap donor buses/engines that california is trying to dump because of new EPA requirements basically outlawing two strokes...that's an idea.
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Get me the number from the cam,it is probably a spare cam for alternator drive side since they do break and they are getting hard to find for a 8v92
Quote from: eagle19952 on June 19, 2018, 09:21:09 PM
well, were i you,
before you get to deep, pull the heads and have them inspected for cracks and warp etc. look at the valve seats.
if the head/heads are toast, look for a gooder engine... ?
If he got it hot and the liners are glazed with black streaks he will need new liner kits too,if they are good shape just hone it and buy new rings.Hillsboro Diesel in Or would have been a good choice but the owner had a stroke and they are in turmoil.
If he was in AZ I would help him out,I have one coming in from WA in Dec that has the same problem plus another 6v92 for rebuild in Oct.
Gnarly it does take a lot of special tools and regardless of what you read and see on the internet the 92 series is not as forgiving as the 71 series when it comes to a overhaul .If you can get it Az this fall I will help you lol what's 1 more.You do need a shop to work on the engine the junk yard style of working on the engine is not the best method plus it is hard on the body crawling around
How is scott Crosby doing this all the time? I thought he did minor rebuild stuff on location? I thought he was self taught too? I don't have the Kahonas to ever attempt an inframe or any such repair so hats off to any of you attempting it. Cliff, you need to live forever to help out the rest of us.
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Quote from: luvrbus on June 19, 2018, 02:01:44 PM
We got those on didn't we Van
Yes that was a bare bones operation facilitated by a motel parking lot. would I do it again? probably. Now changing a Drop box on the side of a road in the summer heat, probably not so much. ;D
Quote from: Van on June 20, 2018, 09:15:20 AM
Yes that was a bare bones operation facilitated by a motel parking lot. would I do it again? probably. Now changing a Drop box on the side of a road in the summer heat, probably not so much. ;D
Lol sometime you gotta do what you gotta do but those rocks hurt ???,on the bright side a good friend came out of that deal
QuoteHow do I know now if it needs a rebuild?
My 2c. If you are asking this question, the first task before all others is get the problem fully diagnosed before plotting a course of action. If it turns out to be minor, your skills and tools can tackle the repair. If it is major, you'll better estimate the total costs, time, and logistics for making the repair.
One thing I can share is the PO of my bus was advised by his mechanic for some time about needing a full rebuild rather than piecemeal multiple partial repairs. The multiple shop visits and repairs kept it alive but cost quite a bit and also suffered lack of reliability. One final breakdown altered his approach and he had a reman motor ordered and installed. Not surprising but the total spend over time and reduced dependability was significantly more than doing the new motor upfront.
They say it is a no-no, but just put some stop leak in the radiator for 12 gallons of mixed coolant and it should stop the leak until you can get it repaired. I'm sure if it got hot enough to melt the O rings on the liner(s) the engine won't last much longer, even though you have lasted for 3 years since the overheat. BTW, the engine shut-down is supposed to activate at 205F and save the engine from overheating which is in the 210f range.
The biggest common culprit in damaging a Detroit is #1 overheating, #2 running out of oil, #3 overspeed. Although allowing inexperienced mechanics work on it.
Many times, damage from overheating may not show up right away. Maybe a couple of thousand miles later.
Quote from: Geoff on June 20, 2018, 01:11:05 PM
BTW, the engine shut-down is supposed to activate at 205F and save the engine from overheating which is in the 210f range.
I remember reading that...what I'm wondering is if it gets to 205 and shuts down, does it prevent any damage? Or is that just preventing catastrophic damage? If triggering an overheat shut down grounds for a rebuild every time?
Also, what do I look for to see if it needs a rebuild before I tear it all apart?
I've activated the 205f shutdown a couple of times in the last 15 years and it didn't hurt my engine at all. You may have gotten it hotter than that due to a bad sensor.
Quote from: Geoff on June 20, 2018, 02:03:25 PM
I've activated the 205f shutdown a couple of times in the last 15 years and it didn't hurt my engine at all. You may have gotten it hotter than that due to a bad sensor.
me too, only in Arizona, wouldn't be there without it.
Lived to tell about it. :)
There should be a warning light that activates at 201-202F before shutdown
Update: We've driven the bus a few times since the coolant start leakingand it's stopped.
The first time we started it up, it stopped leaking when the engine was running. Maybe the liners warm up, expand and seal while the engine is running?
After the first time we moved it, it started leaking about 12 hours later. It leaked 6 gallons in 2 weeks.
We refilled the coolant and drove about 20 miles. This time it didn't leak when we parked. We've driven it a few times since then and kept an eye on it and still no leaking... What could explain that?
I'm not thinking it's fixed and I'm still planning on repairing it but it has me curious.
You'll find out when you finally tear it down.
Just for conversation sake. Years before our in frame, we had coolant get into the oil through a bad O ring on the head (found during a head replacement). At least 3 times over the coarse of twice as many years we added stop leak in the coolant & each time it remedied the problem for a couple years at a time. Not saying it's your fix but it may buy you some time not to mention the fun of experimenting.
Quote from: dtcerrato on July 26, 2018, 06:54:58 PM
At least 3 times over the coarse of twice as many years we added stop leak in the coolant & each time it remedied the problem for a couple years at a time.
What brand stop leak did you use? Thx.
Bars leaks is a good long time brand. There are others out there that others swear by. Some have said oatmeal worked years ago.
A friend of ours said this works well.
http://www.irontite.com/store/index.php?main_page=product_info&products_id=2
I wouldn't worry about stop leak, it probably just leaks when the engine is cold and has a little pressure on the system anyways
Mmm...i didn't think about it but it is about 60 degs here at night instead of 40 when it was leaking. Maybe that's what the difference is.
I've had pretty good luck with K-seal.
Jim