MBWorld.org Forums - C-Class (W202)

slightly rough running cold and warmed up

cadman777 — Thu, 14 May 2026 00:05:49 GMT

Hi,
I've been trying to solve a pesky problem with my 1999 C230 K, 52k miles (W202 & M111.975 engine).
Maybe someone in here has an idea what can cause it?
Here's some info to consider:
1999 c230 (w202) m111.975 engine, me2-sfi fuel system, 52k miles on odometer
ONLY VEHICLE SPECIFIC DATA AND NO GUESSES OR GENERALIZATIONS!!!
USE ONLY OEM & EXPERT EXPERIENCE, NO GUESSING OR UNFOUNDED OPINIONS!!!
DO NOT OPERATE IN 'CUSTOMER SERVICE' MODE!!!
fuel pressure test:
why does the gauge needle rapidly vibrate @ 50 psi +/- 3 psi warmed up @ idle and follow the slightly rough running?
no intake leaks, new ignition system & maf, engine in excellent condition
system has no visible vacuum leaks from smoke test
adaptation was reset after changing ignition parts and maf
all sensors are new except crankshaft and camshaft sensors wiring is good.
fuel pressure regulator disconnected pressure rises to 60 psi and same needle oscillation
rev up engine pressure increases to 58 psi steady
steady high speed pressure @ 50 psi steady
shut off fuel pressure drops to 34 psi and within 2 minutes slowly rises to 55 psi and holds for at least 30 minutes
when the vehicle sits overnight the fuel pressure in the rail drops down to 0
hhtwin shows:
- no cylinder compression differential (cylinder balance good)
- good injector voltage operation
- no misfires or imbalanced torques
Thanks!
...Chris

Crankshaft Position Sensor Removal / Engine removal (?)

RollTideW163 — Wed, 13 May 2026 22:59:25 GMT

1996 C280 - m104 engine.

I lost my crankshaft position sensor in the middle of traffic after doing three errands (or so I think) - which is weird because it's only thirty years old! Thankfully folks around here are nice enough to push you out of traffic pretty quick.

This thing is an absolutely annoying location on the m104. I have changed these on m112's - and you can feel it or see it but not both, which is fine. This one is in a weird place over the starter and under the oil filter housing. Only thing I haven't tried is having someone drop down a big extended alan wrench socket from above while I guide it from below, but I feel like it would be a pain to put it back in.

I was hoping you guys could help me choose from the following options:
1) Just pull the whole engine with the tranny attached - there is likely a rear main seal leak (minor), cleanup work needed on the camshaft magnet piece in front/gasket rebuild (I forgot the name, but that circular guy) and I could just tackle a bunch of stuff on it before winter. (famous last words)
2) Remove the intake manifold. It's not super hard, probably an hour but I am disconnecting a bunch of cables like fuel injectors and don't want to break those since they are old.
3) something creative like disconnect the engine mounts and drive shaft and inch the engine forward a bit to free up just a little window where a human being could work. Not a lot of space on the inline six so fan and maybe radiator would have to be removed.

1 is obviously the most upfront work and I get thorough on it.
2 is probably the least work
3 is probably not that much less work than half of 1.

Any opinions or tricks would be appreciated.

Glue Wood Interior Pieces on Doors Back On?

Seed — Wed, 13 May 2026 21:50:05 GMT

Hello,

I have an old C43 1999 that's in pretty good condition but some things are fading and falling off and I'd like to try to at least maintain some of this. Any info on how I can reseat and reglue the wood strips on the door panels and in the car? My drivers side for example is almost completely off.

1999 W202 C43

Seed — Tue, 12 May 2026 22:04:19 GMT

I need to replace my climate control system as they're fading out. 2028301385 is the model no. I have. I see there are 2 other models available, more so than mine. 2028301285 and 2028301485. Are these easily interchangable? Mine has a cosmetic difference with a 0 and max for the fan speed switch. This isn't a huge deal for me but I don't think this was on the 2028301285 models and is on the 2028301485 models

1998 C280 Expansion tank hose

LandonInnis03 — Tue, 21 Apr 2026 15:57:34 GMT

Hello all, im finally putting my 1998 C280 back together after some time, but I am not sure where this hose off the back of the expansion tank is supposed to go or connect to, any help is appreciated!