amrismail

Hello everyone, I'm new to the MB world and have a problem need your experience. I have a 2003 c230 coupe with the 271 engine, and has a 160,000 Km. the car went to a repairing shop to swap a transmission and radiator ( the radiator was mixing oil with coolant ). after the job is done the car has the roughest idle i have ever seen the total car is shaking badly. and it gave misfire codes on all 4 cyl. + P0131 O2 sensor circuit low voltage bank1 sensor 1. before the transmission swap the engine was running perfect. The only thing happen while changing the transmission is the exhaust link after the catalytic had opened as the bolts were too rusty and broke. but they replace the 2 bolts and the car is shaking since then. I took the car back because they where going to change everything to find the problem. and i did the following:
- changed the sparks - nothing changed
- Cleaned the throttle - it runs fine for 30 sec and shake again
- changed the famous 12$ hose - nothing changed
- Checked all hoses for leak
-Opened and cleaned the EGR valve - nothing changed
- Checked the fuel pressure. it was around 56 PSI

and it always come out with the P0131 code. and last thing was P0010 code ( A camshaft Position Actuator control circuit/open bank 1 ). I you put your foot on the accelerator and the RPM increase to 15 it runs fine. what you think ? is the O2 sensor can give this bad shaking ? and which one is the bank 1 sensor 1, is it the one before the catalytic ? what else should i test..

slammer111

P0131 is an O2 sensor error. The M271 is a 4 cylinder engine, with only 1 bank.

Guessing someone either forgot to plug an O2 sensor back in, or the sensor got damaged. I'd look there first. There are 2 attached to the exhaust manifold.

Don't just throw parts at your car. That will get expensive real fast.

amrismail

Thanks for your response. BTW it is the same exact car in your pic (; as i can see the 2 O2 sensors looks fine without any obvious damage to the plugs or the wires. i will do some further inspection. but if it says bank 1 sensor 1 it means the one before or after the catalytic in case i will get a new one ? i can see they are not the same as they have different plugs.

also the main question is, will the faulty O2 sensor make this rough Idle and misfire??

slammer111

Sounds like you have good taste in colour.

Yes there are 2 O2 sensors. You'll have to check both. If there's any damage, hopefully it's visible.

Anything that can affect air or fuel will result in rough engine operation, such as rough idling or misfires. I'd also look into the MAF. If you still have the old engine, just swap the parts over.

amrismail

I started over today and was looking around the transmission since it was what started all of that and guess what, the mechanic closed the transmission on the O2 sensor wire! it was in the hidden spot at the middle of the upper side. i opened all the bolts and took it out and found one of the wires totally cut and of course short with ground. i fixed it probably and installed everything back. unfortunately the car is still the same. the O2 sensor code is now gone but i still have only one code and i'm not sure if this is what make the car shaking that bad its P0010 ''A'' camshaft Position actuator control circuit/open bank1
do this actuator can do this shaking ?

slammer111

Are your cam adjuster magnet wires plugged in properly? There are 2 of them at the front of the engine. While you're at it, also make sure they're not leaking engine oil. Common problem.

amrismail

well, the actuators are good. I decided to open the valve cover and check the timing ( because it is the worst thing could happen ) the sprockets of the 2 cams were good no wearing the chain is good and tight, the oil looks old and burn on the metal surface. BUT the timing is not aligned. and this is the weirdest thing i have ever seen !! this car was running perfect and went to a shop for transmission swap. and i'm sure no one touched the engine. How this can happen ???
I can understand that the oil pressure can affect the actuator response but how a mis alignment at the chain can happen ? all the teeth of the sprockets are good and the chain is tight. any how this can happen ?

slammer111

The timing can be adjusted internally. If the sprockets look fine then the chain is not the issue. Keep looking. Guessing something else got bumped or pinched during the install.

You checked the circular looking sensors at the front of the engine?

There's also a crankcase position sensor near where the engine meets the transmission. Did it get disconnected?

amrismail

Thank you slammer111 you were very helpful bro. I found the problem and the car is running smooth now. I would like to share my experience here maybe it become helpful in the future. If you have camshaft Position code it could be from sensor ( electrical ) or mechanical ( timing problem ). I advice anyone to go with the small electrical things first ( check wires, connectors, spark plugs ) but do not start to buy and through more in the car without first check the timing. this was my case when i checked the timing i found misalignment, which is weird because no one touched the this part then i started to examine every mechanical part to determine what happen since the sprockets are good and the chain is tight and i found the upper plastic rail is missing a small piece which is hanging the rail from the right side. still the rail is staying good in its place. My explanation for what happen is this piece broke and directly jumped between the sprocket teeth and made the chain to jump one tooth forward and stayed in place after one round. it is 1/ 1000 chance to happen but i just replace this piece and realigned the chain and the car running smooth for a couple of days now.