Jacked a c63

I need some help please.

My C63 is having CEL and misfires.

At first the codes were P0300 301 303 304

I had all my spark plugs changed and reset the computer. The problem went away and the car drove fine for maybe 30 miles.

Now it has really rough idles and shakes really bad slowing down to a complete stop and accelerating from a stop. It threw similar codes just different ending numbers.

Anyone know what this problem is?

I have headers and midpipes and a tune.

hachiroku

intake manifold gasket or bad primary O2 sensors. for my car it was the O2 sensors.

sventastic82

https://mbworld.org/forums/c63-amg-w...then-some.html

w204nyc

I had this issue and i kept replacing sensors and spark plugs and nothing changed. Check for leaks.

hachiroku

are you getting any other codes? misfires generally come with other codes. lean etc. I reset my codes 3-5 times before I settled on O2 sensor replacement.

O2 because once the check engine light came on throttle response would go flat...I tune standalone on the side so I understood that ment the ECU was dumping fuel into the engine to prevent a lean condition. dumping fuel ment running rich ment misfire. hard to explain...a lean condition would result in a different throttle response, not flat.

we'll need to know all the details.

Jacked a c63

No other codes were thrown just the p0300 p0301 302 303 304 305 306 308 (so far those are all the numbers i saw)

The car just shakes violently when idling, slowing down & accelerating from a stop.
The cars start up is weak and quiet as well, not loud like before.
Going up a hill driveway is hard for the hard, i feel like it has no power and it shakes a bit harder on a hill.

hachiroku

wow...pretty much all cylinders are misfiring...I'd recommend bringing to a shop asap and try not to drive the vehicle. better safe than sorry at this point. my misfires were only on one bank of cylinders.

Jacked a c63

Yeah I brought it to the shop twice already.

1st time they changed the sparks and then reset the computer and it was good for a couple hours but then about 30-50 miles later I was driving on the road and I felt that something was wrong with the car(slowly losing power, started to shake a bit) then I came to a red light and it started shaking violently and then the CEL came up flashing and then went solid.

So i went back a second time and the MB technician hooked it up and reset the computers and said something about balance the lean and rich. Then the car was good and so far is still good (I got it back like 5 hours ago)

It's not the same as before though, I still feel like the power isn't all there.. cars has small shakes every now and then.. car startup is weak and quieter than normal... when i drive up my drive way (hill) it shakes a little harder and has trouble getting up compared to before.

I just don't know what the problem is. I read other posts about the P0300-P03### and everyone seems to have different answers... some are leaks, bad gas, sparks, coils, O2 sensors, head gasket, etc..

I can't really just change everything until it goes away because some even say they changed it all and didn't go away.

SROC276

I just replie via email. Yes the car will be slow for about 250/300 miles after a readapt or Ecu reset.

Review gas, then check coils, connections...fuel filter, fuel pump....

Alex.currie44

P0300 is random misfire and the others specific cylinders as I read it. Check this link out.

http://www.autocodes.com/p0300_mercedes-benz.html

jptaylor

check to see if the oil looks like chocolate milk....hopefully not the case but it COULD be that youve had the head bolt issue arise and have got either compression or quenching issues.....hope not but if youre still looking and dont know what the problem is then you also dont know the problem isnt

Jacked a c63

Thanks for the help! I gave the list to my mechanic and told them to check all the possible causes and hopefully it will be one of them.

I went to the dealership and they told me this is a normal common issue because my car is modded with exhaust work and he added that my car sounds great. As soon as i heard that I was like this guy is full of **** and is probably planning on making **** up and charging me for **** I don't need.

Jacked a c63

the oil was the first thing i actually checked, even though i knew it couldn't be because of the oil because I do my oil change every 5-6 months/3000miles. I had it changed in september and drove it less than 1200 miles since then because it got kind of cold up here in NY.

I am PRAYING TO EVERY GOD out there that its NOT the head bolt issue. I don't know much of the head bolt issue, but heard that it's either going to cause me to dump the car or spend 15-30k in repairs. I tried reading about the issue but don't quite understand it because I don't know car terminology that well.

BLKROKT

It's like $3-5k if you do it preemptively (obviously could be much more if it happens and damages the engine). Don't panic.

jptaylor

I wasn't referring to the oil level but the oil color...if coolant is getting into the oil then it will be the color of chocolate milk...also if you remove the oil fill cap on the driver side head it will have a while gummy residue on the underside of the cap

Mark63

I heard of this issue being common in the w204 c63.

Where are you located upstate NY? How far is your drive to Long Island?
I have a mechanic around here that worked on my C63 and some other c63's that might be able to help you out. They have a mercedes specialist that works with them so he can probably help you out.

Jacked a c63

3-5k is still a lot of money, how do i know if its the headbolt issue if the dealership can't even determine its the headbolt?

I don't want them saying its the headbolt, making me replace it and then the problem is still there LOL because i might as well kill myself after that.

Also if i replace the headbolt, will the headbolt issue ever come back?

Jacked a c63

the oil color still looked good, isn't wasn't like a chocolate milk or coffee color, not even close. i remember checking the coolant cap though! i had a little bit of white crust kind of thing around the cap but not a lot.

Jacked a c63

This has been a nightmare for me, the dealership keeps telling me to change **** when they don't need to be changed. They say its because of my headers and exhaust and tune.

i live like 4 hours away from long island. I would drive there if my car was in good condition but I'm scared to drive it that far since its already shaking and scaring the crap out of me driving from my house down the road.

BLKROKT

Go to a different dealership

CarHopper

Did a tech ever mention the o2 sensors?

How many miles on the car?

It would be weird to have both sides fail at the same time, but also could indicate you're having an issue because of the headers as well.

How long have you had the headers on?

And lastly, have you contacted the tuner for possible solutions?

If the problem persists, I would revert back to stock instead of driving it continuously knowing that there is an issue. I know that it is a pain but I'd rather do that than risk damaging anything. Granted, the reason the car is cutting power and such is to protect itself, but if you romp on it the car can only protect itself so much.

cornerjunkie

What's your mileage? If it's up there, you may want to try and replace the coils and then go from there since you already replaced the plugs. You can spend a lot of money trying to search for a hidden leak. At least coils will have a definitive resolution if that's the cause.

hachiroku

what are your short term and long term fuel trims?

C SEXY 3

If you want to find out if it's your intake gasket get some brake cleaner and spray around your manifold around the intake banks. If you have a leak the engine will sputter if you don't move on to a different problem. I had the same codes on my car and I replaced the intake gasket went away.

Jacked a c63

Funny that you mentioned my O2 sensor

Today while driving it with my mechanic a CEL came on and a new code P2629 (o2 sensor pumping current trim circuit/open bank 2 sensor1)

I have almost 60k miles

Headers i've had for two years already.

I haven't contacted OE tuning yet. I probably should.

The shops want to charge me 1500-1900$ to put my stock system back.