Community Forums

rrthor · 04-09-2016, 07:23 PM

Looking around today I saw a little soot around one of my exhaust manifold ports (see picture). Looks like I will need to fix it. For anyone who has removed the exhaust manifold would you help answer a few questions.

1. Can the exhaust manifold be removed keeping the turbo in place. So first I remove the bolts attaching the exhaust manifold to the head and the four nuts attaching the turbo to the exhaust manifold. If I then separated the intake pipe from the turbo would there be enough movement in the turbo to slide the exhaust manifold straight up.

2. Do i even need to remove the exhaust manifold. If I was able to pull the exhaust manifold back a quarter inch or so could I sneak new exhaust gaskets in.

I realize that this motor is known for cracked exhaust manifolds. I do not hear an exhaust leak. I cannot see it cracked anywhere but I realize I can not do a good inspection with it assembled to the head. I would really like to put off manifold replacement. Anyone have some thoughts. Thanks

Old Scout · 04-09-2016, 07:33 PM

Havent done it myself but have heard the following: 1- very good chance you will break a bolt, and if not, all bolts should be replaced as part of the repair [inpact on "sneaking new gasket in"--dont know]

2- I suspect many repair shops try to unbolt the trubo and tip it out of the way--problem is the "flexible" exhaust pipe that connects the turbo to the muffler isnt very flexible once it gets rusted inplace. Have heard several owners say their exhaust pipe broke at the muffler after manifold work--hummmm?

rrthor · 04-09-2016, 08:03 PM

Yes broke bolts. So I am thinking to myself do I do this job myself or take it to a shop. If I break a bolt I have to deal with it. Then I am thinking I start soaking the bolts with penetrating oil every day for the next week. Then one by one I back off every bolt one turn. If I make all twelve I keep going a turn at a time. If I break one I tighten the rest and head to the shop. I called the shop this morning. They said figure 1/2 hour labor per broken bolt. They must be good at removing them.

GraySeal65 · 04-09-2016, 08:24 PM

As a professional mechanic I wouldn't think of touching that without a torch (oxy/acetylene) and my impact hammer gun.

stuhly · 04-09-2016, 08:42 PM

Another trick along with the torch and hammer gun is to give each bolt a couple of good hard smacks with a hammer before you try turning them.

greenmachine · 04-10-2016, 05:12 AM

Most of the time the weakest link on the bolt is in the manifold. If it does break, finish removing the manifold and take the next size bigger nut and slip over the broken bolt. then weld the nut to the bolt and you want it hot. then come back the next day knowing she is cool. Try to unscrew it. Sometimes we don't weld very good and have to try again. Most of the time it will come out. Then If you did break bolt off even with the head. Put the manifold back on and use the same size bit as the hole to mark center. They make a tool for that but nobody has it. Then start drilling until you can get a large easy out there. When you heated it up with the weld you took the temper out and it expanded and then it cooled off and has broke the seal. That works for me most of the time in the back yard.
Larry
2003 38FD Alpine

NHRA225 · 04-10-2016, 05:42 AM

Quote:

Originally Posted by rrthor

Yes broke bolts. So I am thinking to myself do I do this job myself or take it to a shop. If I break a bolt I have to deal with it. Then I am thinking I start soaking the bolts with penetrating oil every day for the next week. Then one by one I back off every bolt one turn. If I make all twelve I keep going a turn at a time. If I break one I tighten the rest and head to the shop. I called the shop this morning. They said figure 1/2 hour labor per broken bolt. They must be good at removing them.

Then soak them some more. Did my 8.3C 10 yrs ago- Broke 2 bolts off, just welded a nut on and worked them out. Maybe I was lucky.
I removed the Manifold to clean up the Head mating surface and installed an updated new heavier Manifold.
I will warn you that the job could be 8 to 15 hours of labor, maybe because I took my time.

gatorv · 04-11-2016, 07:19 AM

Just did my 8.3. Cracked manifold. Soaked mine with penetrating oil and no broken bolts. You might as well take your turbo off first to make it easier. More than likely it will need rebuilding too. My ran fine but turbo was out of spec's and needed rebuilding. I bought all new bolts,gaskets and manifold from Cummins. Good luck.

rrthor · 04-11-2016, 08:45 AM

Thanks for all the responses. I think I will go forward with a week of soaking the bolts and will try to do this myself. We have a state park reservation in two weeks and I will begin after that since I won't need the coach for a month after that.

SteveS · 04-11-2016, 05:27 PM

Rick - Presume you have an ISL but the manifold looks the same as the ISC. I did like others mentioned...sprayed penetrating oil on bolts a few times over about three days and had no trouble removing bolts...other than hard to get to. Left turbo in place but was a little challenge working the exhaust off it and getting it back in. When replacing bolts I used anti-seize compound to help ensure they would not seize if they needed to be pulled again.

greenmoose · 04-24-2016, 07:27 PM

good info. I have a similar but worse problem. my 5.9 Cummins ex manifold did the heat shrink thing and broke the two rear bolt ears off the head. when I say rear, I mean front because it's a pusher and the engine faces the rear) I wish it was only a broken bold or manifold. does anyone know of a fix for this other than replacing the head and manifold?

rrthor · 04-30-2016, 03:59 PM

Okay I just finished removing the exhaust manifold. No broken bolts. I have been soaking them for a week. I did not use any heat. I got 3 of the 4 studs out that retain the turbo to the manifold. That was enough to allow me to lift the manifold straight up. You do have to push the turbo over a little, no more than an inch. I disconnected the coolant line from the block to the turbo because it is a rigid line except for a short flexible vibration isolator in the middle of the line. I didn't want to break it. I did get new bolts, gaskets and studs. I need to go back to Cummins though because i did not get the gasket that goes between the manifold and turbo.