ImperialTech

Hello Everyone,
I'm a long time lurker on the forums for trying to learn new things, and I finally decided to join to see if I could get a few questions answered:

I have a 2007 C230 my parents got me for my graduation gift back in 2022, and the car while not a true lemon, is just above it by virtue of being a lime. It's actually a decent car when she's not being abhorrently temperamental, but I will concede I've learned a lot of auto tricks just by tinkering around with her.

So recently I had a new ECU and O2 sensors installed on the car after the ECU went kaput and the O2 sensors literally blew up (don't ask). However the car has been giving this very weird idle wherein when in park and neutral, the car is completely fine, runs normal, but in drive, the RPMs drop a slight bit more that I remember pre-ECU swap, and the car will do this unusual pulsating idle that feels literally like the car is ever so slightly revving. But the catch is the car isn't revving at all: the RPMs remain firm and solid, nor has the car ever felt as if she was going to cut off. It is so slight until it's only noticeable in the cabin as well, I once sat with the car in drive holding the brakes and held the door to see if I noticed the exterior of the car shaking, and no dice, it's almost entirely interior.

Now I've changed all the sparks and coil packs, have had an oil change as well. Furthermore I have a new alt and serpentine so neither should be an issue there.

My first thought was maybe engine or transmission mount, but it typically happens after she's gotten up to temperature, and/or a long arduous drive. Also something I've noticed is that when cranking from a hot start, a slight drop in performance occurs, especially with uphill acceleration being tougher than normal. I'm used to the janky Drive by Wire, but I'm not used to having to almost floor it to find another gear. Which leads me to my second consideration: crankshaft position sensor? My dad's BMW Z3 had a similar experience with the difference being no hot starts (or if possible, really hard to crank) until I got around to changing it out. Mind you, I have no codes on my C230, but if I recollect, the CPS notoriously doesn't give codes often and can fool you for some time before you realize what's going on. Any advice on my idle oddities would be much appreciated!

Now the next gremlin is something I saw mentioned on the forums a while back but can't find it in good detail. My seatbelt light keeps coming on and dinging at times, despite most certainly being buckled in. To my understanding there's a wire under the seat somewhere that could be messed up? If someone could explain the whole processes in detail for me to see about getting that sorted, I would really appreciate it. While I can take a lot of annoyances, sitting hours in Atlanta traffic to hear a "ding" every so often....I can't turn my Bowie CD up loud enough sometimes...

Finally, so my C230 is the Sport variant with the AMG "package" on it to make it look more expensive that what it is and has that rear sun visor that can be let up and down. Well the issue is I let my mom drive the car a while back, and she loves having it up, while I prefer having it down. Well, she let it up and it got stuck. I fiddled around with it, and got it to go back down, and requested the next time she drive it, to please not let it back up.

She let it back up and it got stuck.

Anyone have any ideas about how to get it down, or is the motor probably kaput? If so please advise on the best way to handle such a situation. Thank a million!

KevinH2000

I don’t have any suggestions regarding the performance problem.

With regards to the sunshade, I offer the following guidance. When I bought my car, the sunshade was stuck in the up position. I tried several different options for putting it down, but none worked. I replaced the motor with a used one. Installing it requires removing the rear seat and parcel shelf. This task is easier if you have folding rear seats, but it is not something I want to do often. The replacement motor works okay, but it still gets stuck in the up position. I lubricated the tracks, but that doesn’t completely resolve the problem. When the shade sticks in the up position, I am able to lower it by pressing the “arms” together while someone else presses the control. I’ve decided that the benefits of the shade don’t justify the effort I expend lowering it when it gets stuck. So, I don’t use it.

I have a black car with a black interior and I live in an area where the summers are hot. The car interior probably reaches well over a 100 Fahrenheit when I leave the car outside at work. I have seen comments that suggest the sunshade motor is adversely affected by extreme temperatures. It appears that I will need to either replace the motor with a new one or live without the benefit of the sunshade. If anyone has been able to resolve this issue I would appreciate learning from them.

in your case, you will need to educate your Mom and prevail upon her to forego using the sunshade. You might need to hide the key if she won’t cooperate.

Good luck.

ImperialTech

Thanks Kevin,

That's what I feared for the visor. The worst part is I don't mind it being up, but especially at night it can be difficult to see out the back, and if given the choice of it always being up or down, even being in Georgia, I'd much rather have it down for my own comfort and safety.

KevinH2000

This shows replacement of the entire assembly. If you have folding rear seats, you don't need to remove the back seat. That will save a lot of time and effort.

I only replaced the sunshade motor because the rest of my sunshade was in good shape. The used motor cost $48. I don't know whether new motors are available. My sunshade goes up without a problem. It only sticks when it is deployed. If I ever have some spare time, I may take another swing at repairing it.

C230 Sport Coup

Wow, your ECU died and the 02 sensor exploded?
That sounds like something from Monty Python.
"And now it's time for your 02 sensors in your C230 to Explode!"
How the F did that happen? I been around here for 22 years and this is a 1st.
AND a blown ECU? That happens almost never except maybe in a car that was submerged.

How many miles do you have?
Unfortunately, if you are not aware, you have an 07 M272 engine, which
invariably dies from the dreaded balance shaft defect that effected hundreds of thousands of
Mecedes engines. And then there's the intake manifold which is also notorious,
the swirl flaps are made out of potato chips, which break off and get sucked into the engine.
The cost of repair for these 2 things exceeds the value of the vehicle in most cases,
and Mercedes fought tooth and nail to not issue a recall. Finally a few years ago,
after many lawsuits was forced to provide some support, that is only good for the original owner and
only up to 125K miles, with a sliding scale discount on overpriced dealer repairs for anything below that...
to the original owner. Mostly a worthless resolution since by the time it was announced since most vehicles were past
125K and had changed hands.

ImperialTech

Took it to the shop, they tested the ECU, and I received a phone call while testing it the O2's blew up. I have no idea how they did that, nor what occurred, only that it happened and my O2s were DOA. And while I'm aware of shop tomfoolery, I and several friends knows these guys, lying about what occurred isn't something they would have done (like certain dealerships).

The ECU died but did not "blow up," but it required a replacement nevertheless.

Car has 166k miles on it, I've put well over 40k of them on myself so the recall means diddle to me effectively. However I do remember reading on the manifold and balance shaft issues somewhere. Hopefully it's not that, but given my pre-existing luck with this car...