Looking Under Your Interstate

[SGT DAVE]

Yesterday I had my Interstate up on a lift for a look at the under belly. MB has to alter the exhaust to avoid the tank, so instead of a straight exhaust it curves around the tank. The altered section of exhaust is a different material than MB uses. In addition, that curved piece of exhaust had heavy rust after only 2 years. It will probably have to be replaced within the next year or so.

FYI, the black door hatch that protects the propane ports has a bad latch. I called Airstream and was told they have had problems with the latch and have gone to an upgraded latch.

SGT DAVE

[73shark]

Mine was completely missing when I got it and had been replaced with a paperclip. I installed a screw with the threaded portion facing out and a knob on the cover. There's enough flex in the cover that I can pull it out and up and over the exposed screw. It works great and since I installed a remote propane switch, I very seldom have to open up the outside cover.

[Protagonist]

Mine has held up just fine for two years, aided only by the application of a dab of dielectric (white) grease to the screw threads to lubricate it.

The local Cummins dealer's service technicians tend to crank the latch down too tight, to where I need a pair of pliers to open it again, which isn't necessary. Finger-tight will hold it closed just fine.

I've given some thought to drilling weep holes in the bottom of the black plastic cover, after noticing that it tends to collect road grime inside if I drive in the rain, but keep forgetting when I actually have my drill out for some other project.

[wayneskid]

Originally Posted by Protagonist

Mine has held up just fine for two years, aided only by the application of a dab of dielectric (white) grease to the screw threads to lubricate it.

The local Cummins dealer's service technicians tend to crank the latch down too tight, to where I need a pair of pliers to open it again, which isn't necessary. Finger-tight will hold it closed just fine.

I've given some thought to drilling weep holes in the bottom of the black plastic cover, after noticing that it tends to collect road grime inside if I drive in the rain, but keep forgetting when I actually have my drill out for some other project.

Not sure but I think they are talking about the small plastic cover over the propane fill ports. It's located just behind the curbside rear wheel. You seem to be talking abut the generator cover?

[Protagonist]

Originally Posted by wayneskid

Not sure but I think they are talking about the small plastic cover over the propane fill ports. It's located just behind the curbside rear wheel. You seem to be talking abut the generator cover?

Nope. I'm talking about the cover over the propane fill port, fill relief valve, and the switch for the propane solenoid. After driving in the rain— an unavoidable occurrence in New Orleans— I find a small puddle of dirty water comes pouring out when I open the cover.

[Boxster1971]

Originally Posted by SGT DAVE

Yesterday I had my Interstate up on a lift for a look at the under belly. MB has to alter the exhaust to avoid the tank, so instead of a straight exhaust it curves around the tank. The altered section of exhaust is a different material than MB uses. In addition, that curved piece of exhaust had heavy rust after only 2 years. It will probably have to be replaced within the next year or so...
SGT DAVE

The exhaust on my Interstates was definitely modified by Airstream. I checked the equipment info books I have and Mercedes only offers two exhaust options. The standard exhaust goes straight back and they offer an option that exits on the DRIVERS side. Also I have the MB data card on my Interstate that indicates it was delivered to Airstream with the standard exhaust that exits in the rear of vehicle. That mod by Airstream explains why it rusts so quickly.

[73shark]

When I was putting my exhaust extension on, I noticed that it was definitely not stainless steel tubing.

[Tiato]

The Airstream exhaust extension is definitely a disappointment. AS used economical steel tube that is as we know will be, is prone to rusting. Then to leave it unfinished as it extends past the side skirt….

Bummer they did not use the removed SS mercedes section to create the needed section for the side exhaust.

At least they used decent reflective wrap to shield the tanks, plumbing and valves. Ive not yet had the chance to get underneath after a long hard run to see how hot things get down there to determine if more reflective material is needed on any parts.

[TBSarfari28]

SGT,
Is this new section of exhaust pipe before or after the DOC/DPF (after- treatment system)? If it is before I would have it replaced soon, as the metal deteriorates inside, the material will be trapped by the DPF causing back pressure, the after-treatment system will try to regen more often and at some point (sooner) it will have to be removed and cleaned, but the metal trapped by the DPF usually can not be removed during the cleaning process. This usually means a new DPF, cost could be around 2K for your vehicle.
Hope this helps with your question.
Good Luck.

[Tiato]

The new section is after the DPF.

[milkfish888]

Originally Posted by SGT DAVE

Yesterday I had my Interstate up on a lift for a look at the under belly. MB has to alter the exhaust to avoid the tank, so instead of a straight exhaust it curves around the tank. The altered section of exhaust is a different material than MB uses. In addition, that curved piece of exhaust had heavy rust after only 2 years. It will probably have to be replaced within the next year or so.

FYI, the black door hatch that protects the propane ports has a bad latch. I called Airstream and was told they have had problems with the latch and have gone to an upgraded latch.

SGT DAVE

Hello! Thank you very much for your post! I got the same problem. The black latch for the cover that encloses the propane switch/propane fill port in my 2011 Airstream Interstate was broken and fell off. Were you able to obtain a replacement latch from Airstream? If yes, what is the Part Number for the latch? I wonder if there are some other type of latches, screws...etc. that are readily available that can be used. Thank you very much!