RV News RVBusiness 2021 Top 10 RVs of the Year, plus 56 additional debuts and must-see units → ×


Reply
 
Thread Tools Display Modes
 
Old 10-24-2020, 10:55 AM   #1
Bus Crazy
 
Drew Bru's Avatar
 
Join Date: May 2016
Location: Minnehaha Co., SD
Posts: 1,158
Year: 1996
Coachwork: Amtran
Chassis: International
Engine: DT466
Rated Cap: 65
Cracked Exhaust Manifold

I'd been hearing a new sound coming from under the hood, a high-pitched squeal when I hit the hills. Sounded like a belt squeal but the volt meter stayed constant and it only happened on hills, under load, and there's a bit of a loss of power. This led me to look at the turbo and associated clamps and viola I found that the exhaust manifold has a big ol' crack in it. Since I don't really have the space (or confidence) to work on it, and can't reasonably leave it in a shop for any length of time (we live in it full time), is this a job I could have a mobile mechanic replace in our parking spot? It seems like I should be able to do the job myself but I almost know for a fact that I'd bust a bolt or 12 trying to get the manifold off. We'll have some idle time while we're parked in NC for the winter, so if I were to have the parts on hand is this something someone could do on site? If not, is it a job that could be done at a truck shop in the course of a day? I've tried various goops and hi-temp cements and they got shaken off immediately....it needs to be replaced.

Any words of advice?
Attached Images
File Type: jpg manifold.jpg (168.3 KB, 53 views)
__________________
Our Build: https://dazzlingbluebus.wordpress.com/
Drew Bru is offline   Reply With Quote
Old 10-24-2020, 10:59 AM   #2
Bus Nut
 
Join Date: Mar 2017
Location: iowa
Posts: 472
Year: 1998
Coachwork: bluebird
Chassis: chevy
Engine: 3116 catapillar
Rated Cap: formerly 71 now 2 or 4
cast can be welded or there are muffler puttys that will buy you some time
mmoore6856 is offline   Reply With Quote
Old 10-24-2020, 11:09 AM   #3
Bus Crazy
 
Drew Bru's Avatar
 
Join Date: May 2016
Location: Minnehaha Co., SD
Posts: 1,158
Year: 1996
Coachwork: Amtran
Chassis: International
Engine: DT466
Rated Cap: 65
I tried to buy some time with the JB Weld Extreme Heat first, then the Permatex Copper (thought it would hold better since it's flexible) but neither worked beyond the first couple miles.
__________________
Our Build: https://dazzlingbluebus.wordpress.com/
Drew Bru is offline   Reply With Quote
Old 10-24-2020, 02:13 PM   #4
Bus Crazy
 
joeblack5's Avatar
 
Join Date: Dec 2015
Location: pa
Posts: 1,851
Year: 98
Coachwork: 1. Corbeil & 2. Thomas
Chassis: 1 ford e350 2 mercedes
Engine: 7.3 powerstroke & MBE906
I would use some exhaust putty and wrap some exhaust wrap around. Then keep that in place with metal wire or a hose clamp. Not sure how far the crack goes on the back side but the front side seems to have easy access to weld on location.

Personally I would try that first.. grind it out an clean as good as you can. Get the engine warm .weld it it and then run it hard to get that manifold hot again so that some of the stress can release.

I would go to a good welding shop..black smith.. that has experience how to weld exhaust manifolds.

If it fails you can also braze it but not sure if the turbo gets it to hot.

Good luck.
Johan
joeblack5 is offline   Reply With Quote
Old 10-24-2020, 02:28 PM   #5
Bus Crazy
 
Drew Bru's Avatar
 
Join Date: May 2016
Location: Minnehaha Co., SD
Posts: 1,158
Year: 1996
Coachwork: Amtran
Chassis: International
Engine: DT466
Rated Cap: 65
Quote:
Originally Posted by joeblack5 View Post
I would use some exhaust putty and wrap some exhaust wrap around. Then keep that in place with metal wire or a hose clamp. Not sure how far the crack goes on the back side but the front side seems to have easy access to weld on location.

Personally I would try that first.. grind it out an clean as good as you can. Get the engine warm .weld it it and then run it hard to get that manifold hot again so that some of the stress can release.

I would go to a good welding shop..black smith.. that has experience how to weld exhaust manifolds.

If it fails you can also braze it but not sure if the turbo gets it to hot.

Good luck.
Johan

Thanks. I wasn't sure if it could be welded without removing it, maybe that's an option after all though.
__________________
Our Build: https://dazzlingbluebus.wordpress.com/
Drew Bru is offline   Reply With Quote
Old 10-24-2020, 03:09 PM   #6
Bus Nut
 
BeNimble's Avatar
 
Join Date: Jul 2020
Location: Sacramento
Posts: 502
Year: 1999
it could be welded, but without taking it off, you can't be sure what its like on the other side, and if not done well it will just crack again. Once off, might be cheaper to just replace it, although gotta check on that, it might be a fortune to get a replacement part.
I'd see if you can get one and have it in hand when you hire a mobile guy to come replace it.
BeNimble is offline   Reply With Quote
Old 10-24-2020, 04:27 PM   #7
Bus Crazy
 
Join Date: Sep 2018
Posts: 1,641
Year: 2007
Coachwork: Thomas Built
Chassis: Minotour
Engine: Chevy Express 3500 6.6l
My dad brazed a manifold one time. I recall that keeping the gasket mating surface aligned was an issue and that took some fussing around to get right. It still has to come off. If you have it sitting around, get Some PB Blaster and give the bolts holding it on a shot of that then wait a few days and give it another. Having the engine a little warm can help, but you’ll definitely want to be careful that it’s not hot enough to ignite the stuff. Applying it and then warming up the engine is a good way to go. Regardless of who takes the manifold off, they will be glad for this pretreatment.

If you have the time, I wouldn’t be too afraid to do it yourself. The bolts that are most likely to snap are at the head pipe.
Danjo is offline   Reply With Quote
Old 10-24-2020, 04:35 PM   #8
Bus Crazy
 
Join Date: Sep 2018
Posts: 1,641
Year: 2007
Coachwork: Thomas Built
Chassis: Minotour
Engine: Chevy Express 3500 6.6l
Quote:
Originally Posted by joeblack5 View Post
I would use some exhaust putty and wrap some exhaust wrap around. Then keep that in place with metal wire or a hose clamp. Not sure how far the crack goes on the back side but the front side seems to have easy access to weld on location.

Personally I would try that first.. grind it out an clean as good as you can. Get the engine warm .weld it it and then run it hard to get that manifold hot again so that some of the stress can release.

I would go to a good welding shop..black smith.. that has experience how to weld exhaust manifolds.

If it fails you can also braze it but not sure if the turbo gets it to hot.

Good luck.
Johan
I would not try to do it in place. Itís inviting disaster, as in a fire, and besides, what Nimble says about getting to the back side is also a problem. It needs to come off.

If you are hiring a mechanic, just plan on replacing it. If youíre getting a used one, take a straight edge to the engine-side mating surface to make sure itís not warped.
Danjo is offline   Reply With Quote
Old 10-24-2020, 04:40 PM   #9
FAC
Mini-Skoolie
 
Join Date: Sep 2013
Location: Central California
Posts: 48
Year: 2003
Coachwork: Thomas
Engine: Cummins 24valve 5.9
Rated Cap: 84
I’ve welded and brazed a couple manifolds over the years. I can tell you from experience that welding it in place, it will crack again. To do it properly in needs to be heated and cooled in an oven. I’ve had much better luck brazing them in place and on the bench. Just to let you know that welding in place is not going to be a permanent fix either. Brazing will last a lot longer if you must do it on the bus.
FAC is offline   Reply With Quote
Old 10-24-2020, 04:45 PM   #10
Bus Crazy
 
Drew Bru's Avatar
 
Join Date: May 2016
Location: Minnehaha Co., SD
Posts: 1,158
Year: 1996
Coachwork: Amtran
Chassis: International
Engine: DT466
Rated Cap: 65
Quote:
Originally Posted by Danjo View Post
I would not try to do it in place. Itís inviting disaster, as in a fire, and besides, what Nimble says about getting to the back side is also a problem. It needs to come off.

If you are hiring a mechanic, just plan on replacing it. If youíre getting a used one, take a straight edge to the engine-side mating surface to make sure itís not warped.
Yeah, if it's going to have to be removed I'll just put a new one on. I can order a new kit from NAPA, probably elsewhere too. I'll use PB Blaster in copious amounts. Just wasn't sure if it's a mobile job but it seems like it should be.
__________________
Our Build: https://dazzlingbluebus.wordpress.com/
Drew Bru is offline   Reply With Quote
Old 10-24-2020, 05:13 PM   #11
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 14,144
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
I replaced the manifold gasket on a friend's DT360. opening the doghouse is a huge help for the 3 rear bolts.. we used deep-creep but ive since found Aero-Kroil to be by far the best penetrating chemical.. it isnt great for exhaust manifolds as its tough to get it where it needs to go.. we didnt break any bolts.. we pulled the manifold and turbo together as it seemed easiest that way.. getting to the bolts to try and separate the turbo was going to be tough.. taking the intake boots and V-band clamp loose was much easier.. oil we took loose at the flanges..



had to finagle our way around some heater hoses and air-conditioner pipes..
cadillackid is offline   Reply With Quote
Old 10-24-2020, 05:30 PM   #12
Bus Crazy
 
Drew Bru's Avatar
 
Join Date: May 2016
Location: Minnehaha Co., SD
Posts: 1,158
Year: 1996
Coachwork: Amtran
Chassis: International
Engine: DT466
Rated Cap: 65
Quote:
Originally Posted by cadillackid View Post
I replaced the manifold gasket on a friend's DT360. opening the doghouse is a huge help for the 3 rear bolts.. we used deep-creep but ive since found Aero-Kroil to be by far the best penetrating chemical.. it isnt great for exhaust manifolds as its tough to get it where it needs to go.. we didnt break any bolts.. we pulled the manifold and turbo together as it seemed easiest that way.. getting to the bolts to try and separate the turbo was going to be tough.. taking the intake boots and V-band clamp loose was much easier.. oil we took loose at the flanges..



had to finagle our way around some heater hoses and air-conditioner pipes..
Yeah,The dognose looks easy enough to remove, figured that would make it easier than squeezing into the engine compartment. I was wondering about those turbo bolts...they seem really hard to get to. The kit comes with these bolts so I figured those are expendable.
__________________
Our Build: https://dazzlingbluebus.wordpress.com/
Drew Bru is offline   Reply With Quote
Old 10-24-2020, 05:32 PM   #13
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 14,144
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
yeah with a new manifold you could just bust those off if you had to.. ive done the "loop the round end of a wrench over the open end" more than once to make myself a nice longer handle to either make something come loose or snap it off..
cadillackid is offline   Reply With Quote
Old 10-24-2020, 05:48 PM   #14
Site Team
 
Johnny Mullet's Avatar
 
Join Date: Oct 2017
Location: Ashtabula, Ohio
Posts: 1,441
Year: 1996
Coachwork: Thomas
Chassis: International
Engine: T444E 7.3L
I think those bolts will come out. Looks gravy compared to the rusty stuff I deal with.
Johnny Mullet is offline   Reply With Quote
Old 10-24-2020, 07:20 PM   #15
Bus Crazy
 
Drew Bru's Avatar
 
Join Date: May 2016
Location: Minnehaha Co., SD
Posts: 1,158
Year: 1996
Coachwork: Amtran
Chassis: International
Engine: DT466
Rated Cap: 65
Quote:
Originally Posted by Johnny Mullet View Post
I think those bolts will come out. Looks gravy compared to the rusty stuff I deal with.
Is that right? That's good to hear...cautiously optimistic.
__________________
Our Build: https://dazzlingbluebus.wordpress.com/
Drew Bru is offline   Reply With Quote
Old 10-24-2020, 09:22 PM   #16
Bus Geek
 
musigenesis's Avatar
 
Join Date: Jan 2019
Location: Philadelphia
Posts: 4,241
Year: 2003
Coachwork: International
Chassis: CE 300
Engine: DT466e
Rated Cap: 65C-43A
Quote:
Originally Posted by Johnny Mullet View Post
I think those bolts will come out. Looks gravy compared to the rusty stuff I deal with.
Hey, do you happen to know any good diesel mechs in the Philly area?
__________________
Rusty 87 build thread
musigenesis is offline   Reply With Quote
Old 10-25-2020, 01:30 AM   #17
Mini-Skoolie
 
Shamoke's Avatar
 
Join Date: Sep 2020
Location: S.E Missouri
Posts: 67
Year: 2000
Coachwork: BlueBird
Chassis: All American
Engine: Cummins 5.9L 24 valve
Rated Cap: 78
I have found when trying to get rusty manifold bolts out without snapping them off it is best to use lots of penetrating oil and heat up the surrounding manifold around the bolt. Try the bolt both directions, just wrench it back and forth and keep lubricating it with the penetrate and you will find that, more often than not, the bolt will loosen up for you.
Shamoke is offline   Reply With Quote
Old 10-25-2020, 02:33 AM   #18
Bus Nut
 
Join Date: Mar 2017
Location: iowa
Posts: 472
Year: 1998
Coachwork: bluebird
Chassis: chevy
Engine: 3116 catapillar
Rated Cap: formerly 71 now 2 or 4
that should be a 3 piece manifold. you only need the center. you only have to remove the front one to get it off. brazing is your best option other than real muffler putty.(not jb weld) if you electric weld anything make sure you disconnect your batteries as to not fry your engine computer
mmoore6856 is offline   Reply With Quote
Old 10-25-2020, 09:56 AM   #19
Bus Crazy
 
Join Date: May 2014
Location: West Ohio
Posts: 1,968
Year: 1984
Coachwork: Bluebird
Chassis: International 1753
Engine: 6.9 International
Rated Cap: 65
No putty or external product will work here. In a turbo application, there is upwards of 30 psi in the manifold vs nothing with a gas engine. So you'll have to braze, weld, or replace it to fix this.

The bolts I see in the picture should come off easily. Just make sure you use a good fitting socket. Pound it on with a hammer if you have to. I'd personally use an impact wrench, but some don't like to because you have a chance of twisting the bolts off, but I find the jarring force can help break the bolt free.

On a bolt, a penetrating oil will have very little effect being as the threads are inside the cylinder head with no access to them. If the manifold and bolts are super rusty, you can see a benefit to heating the manifold/bolt up to a good orange color. You'll need acetylene because propane won't cut it. Once sufficiently hot let it cool to room temp. Heating something up that hot will convert the internal rust between the hole and bolt shaft.

I use crown royal 44-30 wire for welding cast. It's a mig wire and works really well. Vee out the crack and drill the ends of the crack so it doesn't spread. Then clean around the area with a grinder and wipe with acetone. I have a propane grill that was free that I put the manifold in, turn the burners on full blast, and once it's as hot as it will go, I'll kill the burners, weld the crack, and peen it with a needle scaler. Then I'll turn the burners back on and slowly let it cool down. Some cast is dirty and is a pain to weld. If this is an OE manifold, there's a good chance you'll have success. Also be sure to flatten the manifold surfaces after all this, there's a good chance they'll be warped to some extent.
__________________
The Silver Bullet https://www.skoolie.net/forums/f11/p...llet-9266.html
Booyah45828 is offline   Reply With Quote
Old 10-25-2020, 11:18 AM   #20
Bus Crazy
 
Drew Bru's Avatar
 
Join Date: May 2016
Location: Minnehaha Co., SD
Posts: 1,158
Year: 1996
Coachwork: Amtran
Chassis: International
Engine: DT466
Rated Cap: 65
Quote:
Originally Posted by Booyah45828 View Post
No putty or external product will work here. In a turbo application, there is upwards of 30 psi in the manifold vs nothing with a gas engine. So you'll have to braze, weld, or replace it to fix this.

The bolts I see in the picture should come off easily. Just make sure you use a good fitting socket. Pound it on with a hammer if you have to. I'd personally use an impact wrench, but some don't like to because you have a chance of twisting the bolts off, but I find the jarring force can help break the bolt free.

On a bolt, a penetrating oil will have very little effect being as the threads are inside the cylinder head with no access to them. If the manifold and bolts are super rusty, you can see a benefit to heating the manifold/bolt up to a good orange color. You'll need acetylene because propane won't cut it. Once sufficiently hot let it cool to room temp. Heating something up that hot will convert the internal rust between the hole and bolt shaft.

I use crown royal 44-30 wire for welding cast. It's a mig wire and works really well. Vee out the crack and drill the ends of the crack so it doesn't spread. Then clean around the area with a grinder and wipe with acetone. I have a propane grill that was free that I put the manifold in, turn the burners on full blast, and once it's as hot as it will go, I'll kill the burners, weld the crack, and peen it with a needle scaler. Then I'll turn the burners back on and slowly let it cool down. Some cast is dirty and is a pain to weld. If this is an OE manifold, there's a good chance you'll have success. Also be sure to flatten the manifold surfaces after all this, there's a good chance they'll be warped to some extent.

So it sounds like the manifold would have to come off to weld it, in which case I'll just replace it instead of going the welding route. It also sounds like the bolts might not be as prone to snapping as I feared. I left my impact wrench in storage, but some strategic tapping with a hammer might help? Do you feel like this could be a job a mobile mechanic would take on, or is a shop necessary? I'm only slightly confident I can do the repair myself (and I don't think I've ever had a bolt extractor work as advertised) so I'm trying to assess the complexity of it. I'd probably hire it out but ya never know.
__________________
Our Build: https://dazzlingbluebus.wordpress.com/
Drew Bru is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 05:20 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×