Annoying Sticky goo....
 

Maybe not very "Technical" but still need some input on this.
2002 E430 with 121,000 miles. Outside of the car holding up great! Inside not so much. Whatever final coating MB put on the steering wheel and other interior surfaces seems to be turning into a sticky gooey mess. Especially on the steering wheel audio/computer control buttons and the stereo buttons.
Has anyone been successful removing this stuff without going full-on MEK?

Thanks....

Adhesive? Try acetone in an inconspicuous spot first.

I don't think it's an adhesive. It is the deterioration of whatever coating they used on interior pieces. Even on a garage kept car, it appears as if it is melting.

From what I've seen with various plastics, the plastic it self is deteriorating / out gassing not any sort of coating that was applied.

With regular use the failing layer rubs off / gets covered in dirt , let the car sit and it just gets sticky.

I've had US domestic cars steering wheels look like someone had covered them in rubber cement after a few months of non use.

I'd probably try denatured alcohol to clean or some similar colored "dirt" powder to cover the stickyness.

Modern plastics have a ID stamping so if you could find what type of plastic is being affected some research could be done.

alot of it is human oils and dirt.I find using a rag with dish soap,and scrubbing hard the wheel,and surfaces good.

It doesn't clean off. You'll have to replace the pieces in question.

I've owned 5 Mercedes and never had anything like that happen. Admittedly the newest is a '97 CL600 and I live in a hot, low humidity part of the country.
Most of my neighbors have newer American made cars but nothing sticky. I don't get it?
Anziani
'97 CL600 56K

I almost wonder if it's the clear epoxy finish over the wood trim

You're probably right. Never thought of that. What could possibly cause that?
Anziani

If he's not the original owner, maybe someone recoated the interior. Or maybe some chemical reaction to something. Seems to only be on places where there is a lot of hand traffic.

It's actually pretty common. 1996-2002 E series. Maybe not all but many cars have this issue. Look at cars for sale on craigslist and zoom in on any pictures of the steering wheels. You'll see interior color wearing off and deterioration all around the control buttons on both sides of the wheel. I think it does have something to do with the oils in skin and the reaction it has with the material used in manufacturing.

Another example of fine German engineering. If it doesn't move up or down or in or out, they are clueless. :confused:
Anziani

The coating is what makes the buttons feel soft, its a sort of velvet finish which delamiminates and turns inside out.

I have used some saddle soap very carefully to remove that, but be very careful as it may even remove the plastic embossing which illuminates the buttons that you are scrubbing.

I have found that cars used by people who apply tons and tons of moisturiser on their hands are the worst. Those folks even wear down PC keyboards.

I have had good results by cleaning the goo off using drug store rubbing alcohol (70% strength). Apply with a towel (works best with a well worn towel, not too fuzzy). Keep rubbing until you can no longer feel stickiness. This will not be a permanent fix. It will have to be re-done in about 3 months, maybe less in summertime. Do NOT attempt this using paper towels. That makes a heck of a mess.

I don't think that skin oils or moisturizers have much to do with this problem. This occurs on parts that nobody ever touches. For example, on my 2004 C class, the worst problem occurs on the little cubby hole storage compartment below the radio. That part is seldom touched, but anything stored in there like a pencil or a comb eventually starts to become stuck. That part is about a hundred bucks. I suppose I ought to just replace it.