W212 E350 2012 sedan. The pano roof was working just fine. Then today, I went to open it, and when I flicked the button, it only moved a tiny bit. I had to hold the button down to get it to open all the way. If I let go of the button, it stops. While it was opening, it was "stuttering", like something was stuck.

It will open and close if I continuously hold the button down each time. But while it is opening or closing, it stutters along hesitantly, making a noise as it stutters along each time.

Anyone have any suggestions for what's going on? Thank you.

When was the last time you had it lubed? The tracks need grease. Also you can check the track for any foreign objects. There were some leaves in mine once, got rid of them and it was fine afterwards. I think you're supposed to lube it every 2 years. They sell a special grease, ECS tuning sells a small tub of it otherwise you have to get this huge tub that will probably last decades as you only need a little bit of it.

https://www.ecstuning.com/b-genuine-.../0019894651~a/

https://www.ecstuning.com/b-genuine-...te/0019894651/

Thanks, cetialpha5.

New info: I don't think its due to a lack of grease. It does a regular pattern of stopping/starting (pulsing) about twice a second as you're opening the moonroof, closing it, or even just tipping it open. If I had to guess I would say it was the motor itself. Is this how a bad/dying moonroof motor acts?

I checked the fuse to the motor and it was fine. Otherwise I guess its ANOTHER trip to the dealership.

I just tried the reset procedures to reset the pano moonroof with no luck.

So I ordered the grease that Cetialpha5 pointed me to. I'll clean out the rails and grease them and see if that helps.

Thanks!!

It's possible it's also the gears. It used to be a problem on the W211.

I have a bit better description of the issue now:

E350 2012 sedan

The pano roof one touch feature no longer works for:

• opening
• closing
• tilting

One touch DOES work for the roof sun shade, and for all other shades and windows.

The pano roof glass will only move when I hold the button in the correct direction. Otherwise it stops. While the button is applied, the pano roof moves in a pulsating fashion, but the motor of the roof door doesn't seem to be broken.

I have cleaned and re-greased the tracks for the pano roof, and have also executed the reset procedures found in the owner's manual as well as others I found online. None of this did any good.

A previous person suggested "gears" as the problem. If anyone has any other info on this problem I'd appreciate it. Thank you.

I've been having the same issue. Brought it to dealership for a typical lube job and they told me they needed to take the whole glass off to get to the root of the problem. At least a $150 job.. The car is still under warranty so I wasn't happy about that answer. I'll do it myself if I have to.

thanks for the info. Any idea what they need to fix?

I'll have to dig up my service record, but what the guy told me was they needed an afternoon to take the sunroof completely out to grease the track and check it over. They didn't seem to think it had anything to do with motor or gears.. However it very well could have been. I did mention this should be warranty work because it was well below the required lubrication period. I didn't feel like spending that much on a lube job.. Especially as it's getting cold out now.

Please help!!! My 2011 E350 pano moonroof just stopped working for no apparent reason. I've checked the fuses and followed the recommendations from the folks on this forum using the reset steps, and discount the battery ran the reset steps again but to no avail.
I get no response or indications of the motor engaging or trying to engaged when I attempt to open or tilt the moonroof, when pull the switch down like I am closing I would hear a click sound that is it!!!
I'd like to resolve the problem myself if I can before bringing it in for service.
Thanks all for your help.