Sunroof uneven when closed, will only move about an inch, and will not fully open
Thread Starter
Senior Member
Joined: Jul 2010
Posts: 250
Likes: 0
From: Charleston, SC
2005 C230K
Sunroof uneven when closed, will only move about an inch, and will not fully open
Hey guys. Couldn't find any other threads that mention this specific problem. Suddenly my sunroof only opens about an inch in either direction (up or back). The motor sounds like maybe it's dying, yet it still works/moves. If I press the button up to crack it open, it only partially opens. If I press the button back toward the rear to open it, it only opens about an inch and stops. I've left it closed because I don't want it to get stuck open, but even when closed it's weirdly uneven where on the back of the sunroof (toward the rear of the car), one side sits above the gasket and the other side sits below it. I'm able to push down on the corner that sits up and it moves. It's as if it won't lock into its final closed position. I've regularly cleaned and lubed the tracks every time I change my oil. Is this just a dying motor issue? Want to get an idea if this is something I can tackle before taking it to a shop and shelling out some major cash. I'll try to get a video of the issue in the next few days.
Already tried the sunroof reset.
Any input is greatly appreciated. Thanks!
Already tried the sunroof reset.
Any input is greatly appreciated. Thanks!
Last edited by jtwillia2; Nov 20, 2018 at 10:51 AM.
Member
Joined: May 2006
Posts: 102
Likes: 3
From: Vancouver, BC
2002 C240
Sounds like you may have to only re-set the sunroof. With the key in the ignition (position 2), move the sunroof switch to the OPEN position, then closed position then to the OPEN position (back/tilt) position and HOLD the switch in that position for approximately 10 seconds. That should re-set the sunroof to open without stopping every inch. You can probably also search "sunroof reset" on this forum. Hope that's all it is.
Thread Starter
Senior Member
Joined: Jul 2010
Posts: 250
Likes: 0
From: Charleston, SC
2005 C230K
Sounds like you may have to only re-set the sunroof. With the key in the ignition (position 2), move the sunroof switch to the OPEN position, then closed position then to the OPEN position (back/tilt) position and HOLD the switch in that position for approximately 10 seconds. That should re-set the sunroof to open without stopping every inch. You can probably also search "sunroof reset" on this forum. Hope that's all it is.
Senior Member
Joined: Jul 2011
Posts: 408
Likes: 40
From: Hawaii
2017 GLA 250, 2011 C63 P31 (p30 w/ lsd) (in repair), 2005 C230 Sport Eurocharged, 2003 C320~sold
Hey guys. Couldn't find any other threads that mention this specific problem. Suddenly my sunroof only opens about an inch in either direction (up or back). The motor sounds like maybe it's dying, yet it still works/moves. If I press the button up to crack it open, it only partially opens. If I press the button back toward the rear to open it, it only opens about an inch and stops. I've left it closed because I don't want it to get stuck open, but even when closed it's weirdly uneven where on the back of the sunroof (toward the rear of the car), one side sits above the gasket and the other side sits below it. I'm able to push down on the corner that sits up and it moves. It's as if it won't lock into its final closed position. I've regularly cleaned and lubed the tracks every time I change my oil. Is this just a dying motor issue? Want to get an idea if this is something I can tackle before taking it to a shop and shelling out some major cash. I'll try to get a video of the issue in the next few days.
Already tried the sunroof reset.
Any input is greatly appreciated. Thanks!
Already tried the sunroof reset.
Any input is greatly appreciated. Thanks!
Thread Starter
Senior Member
Joined: Jul 2010
Posts: 250
Likes: 0
From: Charleston, SC
2005 C230K
when was the last time you lubed the track? that is part of the service B if i recall. If you haven't done it for quite some time that would be the first thing i would do. Clean and lube the track (i dont recall the specific "approved" lube but it is white lithium grease.
Trending Topics
Junior Member
Joined: Oct 2013
Posts: 41
Likes: 4
'02 C32 (S203)
Did a bit of trial-and-error and seem to have fixed it for a short while
- open roof as far up as it will go
- remove sunroof motor
- clean up all the rust that you’ll see on the gear
- push down the highest side of the sunroof so that both sides are equally high
- mount the motor again
- repeat the steps above once more
after that I got the sunroof to fully open all the way up and all the way back. Problem is that it seemed to skip some teeth somewhere again when opening and closing a couple of times more, so I’m back to the original situation..
- open roof as far up as it will go
- remove sunroof motor
- clean up all the rust that you’ll see on the gear
- push down the highest side of the sunroof so that both sides are equally high
- mount the motor again
- repeat the steps above once more
after that I got the sunroof to fully open all the way up and all the way back. Problem is that it seemed to skip some teeth somewhere again when opening and closing a couple of times more, so I’m back to the original situation..
Last edited by Erik C32; Feb 22, 2023 at 11:20 AM.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
MBWorld Fanatic!
Joined: Dec 2003
Posts: 3,275
Likes: 236
From: BC, Canada
2003 C230K Coupe Orion Blue
Even though I've never had this problem personally, I believe the cheap fix is to open up the gearbox and add a washer (shim) to one of the gears. The root cause is the rails getting clogged which increases the load on the motor, causing the cheapo gearbox casing to bulge/distort and throwing the gears out of alignment. There's a thread on this somewhere. Couldn't tell you which gear to shim, or what size washer to use unfortunately.
Also you want to get some unicorn juice and sunroof grease from the dealer (2 products) and keep the rails lubed properly. This is for the coupe. Check with the dealer to see what gets used for the sedan sunroof.
Also you want to get some unicorn juice and sunroof grease from the dealer (2 products) and keep the rails lubed properly. This is for the coupe. Check with the dealer to see what gets used for the sedan sunroof.
Last edited by slammer111; Feb 23, 2023 at 08:07 AM.
Junior Member
Joined: Feb 2021
Posts: 53
Likes: 3
W203 C220 Sedan
I’ve had the sort of the same problem, but the sunroof didn’t close fully automatically, reaching a point that it encountered some resistance and stoped.
The solution that I pursued was removing the entirety of the sunroof (managing it between the headliner that I left on the car, and both front doors, but there is a service bulletin on the matter, but they remove the headliner from the car), disassembled the mechanism and cleaned every single spec of rust that I found in it (the front left side rubber gasket failed, and let water inside the car).
That was the only way that aí found to permanently fix this kind of issue.
The solution that I pursued was removing the entirety of the sunroof (managing it between the headliner that I left on the car, and both front doors, but there is a service bulletin on the matter, but they remove the headliner from the car), disassembled the mechanism and cleaned every single spec of rust that I found in it (the front left side rubber gasket failed, and let water inside the car).
That was the only way that aí found to permanently fix this kind of issue.
Junior Member
Joined: Oct 2013
Posts: 41
Likes: 4
'02 C32 (S203)
I fixed the problem by replacing the gear with a slightly oversized one (19 teeth, 17.3mm, found on Ali for 8 euros) and letting it sit a bit higher when I put it on. Letting it sit a little higher on the shaft has the effect as putting a shim under the shaft.
Even though i cleaned and greased everything i could reach it is still going a bit slow, so i guess taking everything completely apart and cleaning and greasing the cables would be the best solution to prevent any future issues.
Member
Joined: May 2021
Posts: 121
Likes: 22
From: Melbourne, Vic, Australia
C230K M271 CL203 2003 model
The 2 gearbox casings are identical!. It is a simple matter to swap them over!.
This will place the good gearbox casing onto the other side where it will do the most good. As it is not as warped as the one you removed, it will make the sunroof function like new!,
The distorted casing can go on the other side for the sunblind, which has less work to do, and does not mind that it is a little warped.. this worked for me!
MBWorld Fanatic!
Joined: Jun 2002
Posts: 7,263
Likes: 169
From: So. Oregon Coast
C230 Sport Coup + 2006 W164 ML350 + 99 Ford Escort RIP
At some point it will fail, you will no longer want to use it, lest be stuck with it open.
Check for thread with user Davedrb I think it is, he did a complete rebuild of the sunroof.
Check for thread with user Davedrb I think it is, he did a complete rebuild of the sunroof.
Currently Active Users Viewing This Thread: 2 (0 members and 2 guests)
