98 Cummings ISB Exhaust Manifold

[westek]

Hello,
I'm new to this forum and RVing in general. I purchased my 98 Holiday Rambler Endeavor with 47K miles last year and lived in it for about 3 months.(loved it!!!) Moved it here to Florida for a little while and now am getting it ready for some more travel. To make a long story short, I discovered a crack in the exhaust manifold. After a little research I seem to have discovered that this happens on this engine(ISB Cummings) and that a manifold with expansion joints in it are available to fix this problem. Looking at the engine from the top(see attached photo) you can see the crack. You can also see an expansion joint in my manifold. I was under the impression that the original manifold had no expansion joints, please someone correct me if Im wrong. This makes me wonder if the manifold has already been replaced by the previous owner. FYI the picture I saw of the replacement manifold had 2 expansion joints. It would be great if someone that has had experience with this setup to chime in and help me lay this bag of snakes out straight. Also Im a pretty decent mechanic, would someone that has done this repair suggest doing this or take it to a diesel mechanic. I am on a retirement budget. Thank You for any input one may offer.

Regards,
William

[J Walker]

A replacement exhaust manifold is in three pieces as I recall. It allows expansion and contraction without as much stress on the manifold. Yours looks like one piece. I have a 200 ISB and will probably have to replace my exhaust manifold at some time. I will pay to have mine replaced when the time comes. Bolts are often stuck and I don't want to deal with that.

[Paul R. Haller]

J walker is right. The original manifold over time will shrink and in some extreme cases break the ears off the head because it shrank so much. The replacement manifolds come in 3 pieces with an expansion hub at #2 and #4 cylinders and are made by an aftermarket company of higher quality cast iron that is less prone to shrinkage. I have also replaced one that was shrinking with an expandable type. The hardest bolts to remove are #1 and #6 because that's where the most shrinkage is seen. They can be quite hard to get out. It's been a while but my memory is that it took about 3 1/2 hours to remove and replace the exhaust manifold the first time. After that initial learning curve, it takes much less time to R and R it. It helps to spray everything a day before the job with Blaster or Liquid Wrench to help loosen the nuts and bolts on the manifold. Reassembly is usually done with plenty of anti seize compound to make life easier for the next guy.
-Paul R. Haller-

[sjholt]

What will work on that 24v for an exhaust is an ATS 2 piece exhaust manifold for a 2003 cummins and up.
It has an expansion joint right where your crack is.
You have the turbo towards the rear of the engine so you can't use a 3 piece manifold.
I installed the same one on my 12V motor and it has been working fine for the last 40k miles( yes-it will work on the 12V.
What caused the crack was heating and cooling of the manifold causes it to shrink over time. On my 12v- the two outward bolts broke because of the shrinkage.
Another stock manifold may last as long or longer.
Ya pays yer money and take yer chances.

[Triker56]

The OEM is a 2 piece replacement.
Make sure the turbo isn't against it anyplace.

Changed mine 3-4 years ago.

[sjholt]

>>>Make sure the turbo isn't against it anyplace<<<

Duh? The turbo bolts directly to the exhaust manifold....

[Triker56]

Quote:

Originally Posted by sjholt >>>Make sure the turbo isn't against it anyplace<<< Duh? The turbo bolts directly to the exhaust manifold....

Duh! The Turbo part is not fixed, at the position it attaches to the exhuast manifold.

It can be turned(rotated) to be against the manifold coming out of the cylinders when installed.
That spot where they joined is where my OEM ISB 2 piece manifold cracked and had to be replaced.

If installed with the turbo part aginst the manifold when cold.
The heat when running expanding the manifold & the Turbo. Can put pressure on the manifold.

Isn't it great to learn something new, about something you thought you knew everything about it.

[sjholt]

Double DUH!
It is plain to see that you never worked or pulled the turbo.
Give it up man!

[Triker56]

You are right. I didn't do the work. But the Cummins certified technician that did, showed me what caused the problem. Before it was removed.

And after removed from the manifold,he used over 2 cans of penetrating fluid to break the turbo lose, so it could be turned away from the manifold.

That's my story and I am sticking to it.
Your experience may be different. Not that anything is wrong with that.

[Happycarz]

The Holset turbo is comprised of three sections, that will rotate, when the band clamps are loosened, in relation to each other. The turbo exhaust housing, which is bolted to the engine exhaust manifold, is in a fixed location. The center section can be rotated in relation to the exhaust housing, and the inlet housing can be rotated in relation to the center section. There isn't much leeway with the center section as oil feed and drain tubes must be pretty much in a standard configuration. But, the inlet side can be rotated over 90* to align with the coach builder's location of the pipe/hose to the intercooler (CAC.) Maybe this will help explain what Triker56 is trying to get across.

On my 99 Dynasty with the ISC, I installed a Banks kit that came with a new turbo housing that I changed. That one used bolts and special trapezoidal washers to connect, and "clock' two of the sections. To have everything line up when done, the turbo had to be "clocked" correctly.

On my ISL, the center section was "clocked" so far out of spec from the factory, that the oil return line was compromised. See picture below. This one, Holset 40 VGT, has the band clamps between the three turbo sections.

[Triker56]

Sjholt probably feels like this now.
Or a Triple DUH!

Thanks for explaining how it works Happycarz.

I'm only a barnyard mechanic. And do all of my own maintenance of all filters & fluids on my DP.

Back in "57" I did take a OEM engine out of a "54" Ford 2 door hardtop. And replace it with a engine from a wrecked "57" T-Bird with more cu in & HP.
Without any help. Also changed the OEM rear end to a 4:11:1

All the other 57's around never could figure out how a low powered(first year of the OHV) "54" could out drag them.
I never did tell them how either.

[sjholt]

I think your mechanic was full of B.S. and it didn't take 2 cans of penetrating oil to get off the nuts, he was full of it about the turbo being clocked wrong.
The exhaust manifold is bolted directly to turbo and that cannot be clocked wrong. The compressor side is tied to the hosing that goes to the CAC and that can't be clocked wrong. The only thing that can be clocked wrong is the center section and since the lower drain hose goes directly to the pan- that can't be clocked wrong-- Unless some idiot(your mechanic) was working on it before.
I have removed and replaced my turbo and exhaust manifold three times now to get all the leaks sealed and rebuild the turbo.

Skip- A.S.E. Master Mechanic for 30 years!

So quadruple DUH!

[Ray,IN]

To pacify my curiosity, what EGT' readings are you guys with broken manifolds seeing?

[sjholt]

Actually not that high. When I blew out some "blow proof" exhaust gaskets(always use stock steel gaskets). The AFC(automatic fuel control) on my 12V 5.9 mechanical diesel limited the amount of fuel because it wasn't seeing any boost. It is sorta a safety device that keeps from burning the pistons up under low boost conditions. I could still do 55 mph on the flats and 35-45 in the small hills from Wikieup to Phoenix.
HTH