we discovered today that we have a cracked exhaust manifold on our cummins 8.3 ISC. local diesel repair shop says this is pretty common in motor homes. anyone concur ? looks to be about $1000. in parts to replace. (estimate from Cummins northwest)we noticed a loss of boost pressure and a higher than normal EGTs the last hour of our return trip yesterday. Today Started the inspections to see why, and found the crack is totally around the casting between #2 and #3 cylinder. fortunately nothing burned in the area.

Yes, it's a very common failure mode. How many miles on it?

sch911 wrote:Yes, it's a very common failure mode. How many miles on it? a bit under 50kCause ?

Between 2 and 3 or 3 and 4 (in the "larger part") not the short front part??

wolfe10 wrote:Between 2 and 3 or 3 and 4 (in the "larger part") not the short front part??Read the post.

cracked exhaust manifold | Good Sam Community

dons2346
Explorer
Sep 30, 2016
I had Motor Truck in Bellingham replace mine a few years ago. IIRC, the parts were under $500 and labor ran about the same. No way should parts cost $1000
Tom_Barb
Explorer
Sep 30, 2016
johnhicks wrote:
Assume $2500. The tech will break a bolt or two. It's common.

The Tech is me.. I do all my own maintenance, always have.

This is nothing more than replacing a part, oh but a big one.

If I had to remove the engine, I'd take it to Motor Trucks in Mt. Vernon, they have power lifts.
johnhicks
Explorer
Sep 30, 2016
Assume $2500. The tech will break a bolt or two. It's common.
wolfe10
Explorer
Sep 30, 2016
OK, Tom.

But this video shows the more common break on the C and L:

https://www.youtube.com/watch?v=ymlYNwHyS3A

Though it was worth asking.
dstock50
Explorer
Sep 30, 2016
Cast iron ? will braze !
Tom_Barb
Explorer
Sep 30, 2016
wolfe10 wrote:
Between 2 and 3 or 3 and 4 (in the "larger part") not the short front part??

Read the post.
wolfe10
Explorer
Sep 30, 2016
Between 2 and 3 or 3 and 4 (in the "larger part") not the short front part??
Tom_Barb
Explorer
Sep 30, 2016
sch911 wrote:
Yes, it's a very common failure mode. How many miles on it?
a bit under 50k
Cause ?
sch911
Explorer
Sep 30, 2016
Yes, it's a very common failure mode. How many miles on it?