Thor Tuscany diesel- cracked exhaust manifold

[Kminor28]

My Tuscany is at a Freightliner shop for repair of an extremely loud noise at the rear of the coach (diesel pusher) when idling. It goes away when I place it in drive.

Freightliner just called and said my exhaust manifold was cracked and quoted $4700 to replace it.

Any idea how I could crack an exhaust manifold on a diesel pusher class A?

[EA37TS]

New, used, age, mileage?

[Kminor28]

2016 with 36K miles on it. All regular maintenance performed.

[saddlesore]

Normally caused by warpage.
This could be caused by not allowing the engine to "Cool Down" a couple of minutes after a hard pull, before shutting the engine down. [quite common on the early GM gas big blocks And [Early 855 block] Cummins Diesels.]

[Kminor28]

Thanks. Makes sense.

[EA37TS]

7 years old, my guess would be metal fatigue. Exhaust manifolds are usually cast metal components and the overall thickness and quality of the cast can vary from part to part.

[16ACE27]

Originally Posted by Kminor28

My Tuscany is at a Freightliner shop for repair of an extremely loud noise at the rear of the coach (diesel pusher) when idling. It goes away when I place it in drive.

Freightliner just called and said my exhaust manifold was cracked and quoted $4700 to replace it.

Any idea how I could crack an exhaust manifold on a diesel pusher class A?

Might want to check for quotes elsewhere. $4700 to replace an exhaust manifold? Does that include new turbo units as well?

[EA37TS]

Originally Posted by 16ACE27

Might want to check for quotes elsewhere. $4700 to replace an exhaust manifold? Does that include new turbo units as well?

I’ll bet 1k of that quote is the Class A diesel pusher surcharge.

[RACarvalho]

What Saddlesore said above is the cause and it is called "Hot shut down", it not only affects the exhaust but also reduce the life of the turbo...

As for cost, $250 for the manifold, $60 for gaskets plus $300 for labor and the rest is "rich guy with a diesel pusher" surcharge...

It is not a difficult job.

[DavidEM]

Originally Posted by RACarvalho

What Saddlesore said above is the cause and it is called "Hot shut down", it not only affects the exhaust but also reduce the life of the turbo...

As for cost, $250 for the manifold, $60 for gaskets plus $300 for labor and the rest is "rich guy with a diesel pusher" surcharge...

It is not a difficult job.

Those numbers look way too low. Admittedly, $4,700 looks high but not as high as the above numbers look low. I would have guessed about $3,000.

David

[RACarvalho]

Originally Posted by DavidEM

Those numbers look way too low. Admittedly, $4,700 looks high but not as high as the above numbers look low. I would have guessed about $3,000.

David

Exhaust Manifold:
https://www.fridayparts.com/exhaust-...la-us-all-8.13
Gasket:
https://dieselpro.com/cummins-exhaus...sket-4283.html

Need to check the correct part number but will not fall far from this...

[The Gritz Carlton]

Originally Posted by EA37TS

I’ll bet 1k of that quote is the Class A diesel pusher surcharge.

I worked for a commercial truck dealership years ago...they literally hated to see motorhomes...especially the A's...pull into the service area. Access to the engine normally required disassembling lots of non-chassis parts and pieces. They always quoted like the didn't want the job but rejoiced if their price was accepted. I've seen entire bedrooms and cabinetry have to be removed for access to engine. 3 to 4 times what the same repair would be to an engine mounted in the front of a regular work truck.

[EA37TS]

Originally Posted by The Gritz Carlton

I worked for a commercial truck dealership years ago...they literally hated to see motorhomes...especially the A's...pull into the service area. Access to the engine normally required disassembling lots of non-chassis parts and pieces. They always quoted like the didn't want the job but rejoiced if their price was accepted. I've seen entire bedrooms and cabinetry have to be removed for access to engine. 3 to 4 times what the same repair would be to an engine mounted in the front of a regular work truck.

That’s what’s nice about my Super C, I pay truck rates and not Motorhome rates. Last LOF service was 200.00 more for a Class A DP with the same engine.

[DavidEM]

Originally Posted by RACarvalho

Exhaust Manifold:
https://www.fridayparts.com/exhaust-...la-us-all-8.13
Gasket:
https://dieselpro.com/cummins-exhaus...sket-4283.html

Need to check the correct part number but will not fall far from this...

Isn’t that Cummins manifold water jacketed for a DP, just like in a boat?

David

[lwmcguir]

The Oasis dealerships, and others that specialize in DP's, have pits with various sliding platforms that they use to access the engine. Combined with the hatch open in motor homes you can get most of the needed work done.

There are some without the access and I can see it being quite a job.

Back when my alternator failed at 15k it took the technician all of 20 minutes to exchange it from the bottom using the pit.

No doubt FRED'S make a lot of sense regarding easier access.

Searching IRV2 might give the OP a feel for what others are or have paid.

[simidrm]

What engine?
I can see that price as that requires removing the turbo, draining coolant, and all the gaskets and o-rings that are required in that job not to mention the marmon exhaust clamp if it breaks, my question is why did the manifold crack ? Loose motor mounts allowing engine to torque against the exhaust, exhaust temps to high from turbo or air to air cooler, also I would ask to see the manifold because there is a stainless accordion style tube off the egr valve that do go bad more often, just above the manifold but a lot cheaper to replace.

[lwmcguir]

Isl9

[The Gritz Carlton]

Originally Posted by EA37TS

That’s what’s nice about my Super C, I pay truck rates and not Motorhome rates. Last LOF service was 200.00 more for a Class A DP with the same engine.

A huge consideration when we decided on the Super C vs the Palazzo. Same floor plan but the truck part stuck out the front...not buried under the coach construction. Equally, why I recently went with the Sprinter chassis...everything chassis sticks out the front and stands on its own. I wouldn't buy an A class for any amount of discounted money.

[SteveW]

Originally Posted by Kminor28

My Tuscany is at a Freightliner shop for repair of an extremely loud noise at the rear of the coach (diesel pusher) when idling. It goes away when I place it in drive.

Freightliner just called and said my exhaust manifold was cracked and quoted $4700 to replace it.

Any idea how I could crack an exhaust manifold on a diesel pusher class A?

More than likely the manifold cracked due to overheating. When you make a hard climb or work the engine hard for an extended period of time, you can not keep your foot in it. The exhaust temperature rises very fast say climbing up a mountain. Most diesel engines have a pyrometer to measure the exhaust temp. It should not exceed 11/1200 degrees for extended periods.