118d - Car vibrating, hard to shift into 1st. Sometimes red battery light comes on.

[dalexandre]

Hello everyone,

I need some help figuring out what could possibly be happening to my BMW 118d E88 from 2010, before I go on spending a few hundreds in diagnosing at BMW.

Here's some things to consider:

-About 3 and a half months ago, the red battery light came on. The old battery was about 7 years old so I bought a new battery (VARTA A5 AGM 95AH-850A=G14) and had it coded in the system, as it was a higher capacity than the previous one (85 vs 95).
Turns out it was the alternator, so I had the brushes, slip ring and voltage regulator replaced too as they were pretty worn out. That fixed the issue for these past 3 months and a half and the car was running perfectly.


Now recently, the red battery light started to appear. It only appears from time to time, and sometimes it even disappears in the middle of the drive.
Scanner shows error codes 4A17 and 4A18 when the light appears. Using a multimeter on the alternator cables, shows 0 volts when the red light is on, but showed around 13.4v when the light didn't appear.
Also found out that measuring with the positive jumper on the engine block, and negative jumper on any chassis bolt is measuring 24 volts with the engine on.

I noticed that I can also trigger this red light, by connecting an accessory such as a dashcam, or an OBD2 turbo pressure/oil temp monitoring system to the car while driving for a while, turning the car off and leaving the accessory connected. On the next drive the light will 100% come on and not go away even if I disconnect the accessories.

About a month ago I had a stainless steel exhaust installed along with a downpipe and the guy at the shop didn't connect the O2 and temp sensors all the way through, they were hanging half out and I'm not sure what electrical implications that could have caused. I only noticed it after about an hour driving back home and inspecting the work that they made to check for screw ups. (glad I didn't trust them)


Also not sure if it's related, but as of yesterday the car started shaking while in idle. It is also very hard to shift into first gear when stopped and into 2nd gear when moving slow.
I had the clutch and clutch plate replaced about two months ago, and went with a reinforced kit from Sachs.

However I kept the original DMF as the manual said it could be kept with one clutch replacement, only needing replacement on the next one.

Could this be a DMF failure? I also notice some burning rubber smell when moving from a stop, but with the electrical issues too I don't know if it's from the clutch or from the wiring.

There's also a faint white smoke on the engine bay coming from the center that I don't know if it was there before or not.


Also keep in mind I do regular maintenance, every 5000km I use engine flush to flush out old oil and gunk, and always put the recommended Castrol oil, and use ceramic coating to reduce friction.
Turbo is also brand new, has less than 1000km on it and runs smoothly.

Any ideas on what to diagnose first? Lots of things happening at the same time that I have no ideas what to check first and I just know the guys at BMW are going to charge me hundreds for a half assed diagnostic and quote me a whole bunch of parts that probably need no replacement.

[dalexandre]

Update: Took the car for a drive specifically to test out the gears and jittering and it checks out that:

- At around 1500rpm the gears are easier to shift.
- At lower rpms it gets really hard to move the shift knob.
- Engine vibrates a lot even with the clutch pressed on.
- One time the gear did not disengage fully when I pressed on the clutch, as it rejected my gear change as if I was changing it without pressing the clutch.
- One time I downshifted to 2nd, and as I tried moving slowly forward I heard a loud thump and the car stalled and shut off violenty. Possible that the gear disengaged itself.
- Burning smell is definitely from the clutch and not electrical. Smelt more like burnt brake pads than electrical wires.

Considering I put on a reinforced clutch kit, could this have damaged the DMF?

I know bad engine mounts could cause this vibration too, but how bad would they affect shifting gears and cause burning clutch smell?