wtf is this black metal duct under w126 steering column?

[bigblue]

I started pulling things down under the steering column to try to find the cause of my dashboard electrical problems. I'm greeted by a large heavy oily black corrugated steel duct in the way of everything. Got it loose by removing 2 nuts on the side but it's still hanging from a fastener deep inside the dashboard. I'd like to get it out and find out what I'm missing

What is it?
Why isn't it plastic?
Why is it oily? Cabin air intake sucks in engine breather gas?
How do I remove the final fasteners?

I posted here with my original electrical issue behind the dashboard on my new w126. Currently I have no instrumental cluster, the battery light and ANTILOCK light came on at the same time the cluster died.

w126 had a buzz behind cluster, quiet with a smack, now no gauges :(

[W Black]

I would like to know also as it would make it easier to get to the A/C expansion valve.

[dpetryk]

1. Its an air duct.
2. Germans built it.
3. It should be dry.
4. There is a 10mm bolt holding it near the center back. You need a really long 1/4" extension (bout 12" long) with a 10mm socket to get at it. Look down the steering column to see it.

Good luck

[pmckechnie]

Bigblue,
It would help if you could let some of us know what "126" you have. The 126 was made from 81 to 91 I believe and I can promise you they are not all the same. I have a 84 126 that I drive and a 91 126 parts car and very few parts are interchangable except maybe some body parts and some interior parts. I usually just bypass questions like yours because I dont have time to search for details. Today I have a little extra time so I thought I would give you this little trick as far as getting more responces. Have a great day.

[bigblue]

Originally Posted by pmckechnie

Bigblue,
It would help if you could let some of us know what "126" you have. The 126 was made from 81 to 91 I believe and I can promise you they are not all the same. I have a 84 126 that I drive and a 91 126 parts car and very few parts are interchangable except maybe some body parts and some interior parts. I usually just bypass questions like yours because I dont have time to search for details. Today I have a little extra time so I thought I would give you this little trick as far as getting more responces. Have a great day.

It's a 1985 300sd. What's your trick? put the MY as well as chassis in the subject? Thanks for the responses. I don't have a 12" 1/4" extension, only 3/8". won't clear?

I saw that thing once at pull apart. I wanted it off the car and used a crowbar

[Hatterasguy]

Actualy its crash protection for your knee's. It should be dry and clean, something is leaking, your AC system maybe?

[jbaj007]

bigblue,
Go to at top of page; then ; then ; then add you vehicle to your signature and it's in your posts automatically

[bigblue]

Originally Posted by Hatterasguy

Actualy its crash protection for your knee's. It should be dry and clean, something is leaking, your AC system maybe?

Í really don't think it's oil from the AC system because of the color but that is a possibility since the system leaks its charge rather quickly. It's definitely got a thin film of black (most likely engine) oil on and inside it. Oil is accumulating there for some reason. If it's not supposed to be that way then my best guess is that a vacuum motor, regulator or checkvalve in the HVAC system has a torn diaphragm and blowby is getting in somehow. Hopefully I wont be tearing it off with a crowbar but it's nice to know it's only there for knee protection. (because I'd much rather jamb my knees into something steel than soft)

[Hatterasguy]

I think the idea is that nice soft vinyle and aluminum under panal deforms and bends around that steel tube. That way your knees are not torn open on whats under the dash. I am sure MB spent a great deal of time and money designing it.

[Diesel_Canuck]

Originally Posted by bigblue

It's definitely got a thin film of black (most likely engine) oil on and inside it. Oil is accumulating there for some reason.

Perhaps your oil pressure gauge in your instrument cluster is/was leaking.

[Hatterasguy]

Originally Posted by Diesel_Canuck

Perhaps your oil pressure gauge in your instrument cluster is/was leaking.

Not on a W126, they are electric.

[bigblue]

Originally Posted by Hatterasguy

Not on a W126, they are electric.

Damn, I was hoping he was onto something promising (and not indicative of something majorly wrong)

btw I am out of town for 2 weeks which is why I cannot provide feedback on the situation. I started pulling it apart the day I left. I'm really surprised to hear that others have not come across this issue with their diesel w126 cars.

[JimmyL]

Originally Posted by jbaj007

bigblue,
Go to at top of page; then ; then ; then add you vehicle to your signature and it's in your posts automatically

You "lead 'em to water" jba, and still there is no drink taken......
At least you tried.

[bigblue]

Originally Posted by JimmyL

You "lead 'em to water" jba, and still there is no drink taken......
At least you tried.

Hey where's the love?
I indicated the type of vehicle I have within this thread, despite my lack of still providing a signature.
It just so happens that I am travelling for the next week and a half and am unable to put the time into creating an adequate sig. I'm a very active hand's on DIYér and appreciate the helpful advise given to me on this forum and intend on being a contributing member when I am able, as well as abiding to the general forum rules.
Cheers