Another P0300
03-08-2018, 12:18 AM
#1
Newbie
Thread Starter
Join Date: Mar 2018
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
11 W204 C63
Another P0300
Hello all
First time posting here, recently plunged into the world of a W204 C63 AMG, giving up my coupe 2 seater life.
Anyways, I brought my 2011 C63 back in September, and has had very odd hic-cups every now and then at cold starts which goes away fairly quickily.
Today though when my wife came back to a warmed up car, started it up, the car was shaking at idle, and had a notice loss of power, She was close to home so she nursed it home and shut it down. She even stopped, and tried to restart the car, to the same issue.
I plugged my code reader in and gave me a P0300 code, nothing else. The vehicle was running fine up to this point other than a few odd times when it would idle shake on cold starts, but never when its warm. The vehicle was not worked on recently. I would like to remark thatIi replaced the air filter in December as the originals from the previous owners looked like it was never replaced and had about a pound of sand stuck to it. The issue however started fairly recently, not from the air filter replacement.
I then started it after the car had cooled down at night and it seems to be running fine again.
Would anyone have a clue to the issue? I am looking at a weak coil possibly but not knowing which cylinder from the code would be tricky.
Has anyone ran into this random misfire code from a vaccum leak?
The vehicle has about 60,000km on it. Oil and coolant looks like its in fine shape. It runs 91 octane, could it be winter gas?
First time posting here, recently plunged into the world of a W204 C63 AMG, giving up my coupe 2 seater life.
Anyways, I brought my 2011 C63 back in September, and has had very odd hic-cups every now and then at cold starts which goes away fairly quickily.
Today though when my wife came back to a warmed up car, started it up, the car was shaking at idle, and had a notice loss of power, She was close to home so she nursed it home and shut it down. She even stopped, and tried to restart the car, to the same issue.
I plugged my code reader in and gave me a P0300 code, nothing else. The vehicle was running fine up to this point other than a few odd times when it would idle shake on cold starts, but never when its warm. The vehicle was not worked on recently. I would like to remark thatIi replaced the air filter in December as the originals from the previous owners looked like it was never replaced and had about a pound of sand stuck to it. The issue however started fairly recently, not from the air filter replacement.
I then started it after the car had cooled down at night and it seems to be running fine again.
Would anyone have a clue to the issue? I am looking at a weak coil possibly but not knowing which cylinder from the code would be tricky.
Has anyone ran into this random misfire code from a vaccum leak?
The vehicle has about 60,000km on it. Oil and coolant looks like its in fine shape. It runs 91 octane, could it be winter gas?
03-08-2018, 09:57 AM
#2
Member
It took me about 6 months to finally cure my misfire issues and there appear to be many possible causes. Since you have multiple cylinders misfiring it probably isn't several bad coils. I would start out with removing the air box and spraying MAP cleaner on the sensors and make sure you get the boxes sealed properly when installing. Make sure you spark plugs are ok. I changed mine and they had 30k miles (but it didn't fix my problem). It could be dirty injectors and if it is they would probably need to be removed and cleaned or replaced as the pour in the gas cleaner usually doesn't work if they are plugged to the point of misfire. What finally fixed mine was to remove all the fuses and relays in the engine compartment fuse box and putting a lite layer of dielectric grease on the contacts, and then removing the wires from the four ground points in the engine compartment and cleaning and applying the dielectric grease. Please let us know if you find your cure as this can be a very difficult problem to fix.
03-08-2018, 11:01 AM
#3
These are very good and CHEAP suggestions. Checking over those things, isn’t something that could break your bank. This is something you can do in a matter of hours over the weekend. Check these things out, hopefully they fix the issue. Good luck dude
03-14-2018, 12:50 AM
#4
Newbie
Thread Starter
Join Date: Mar 2018
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
11 W204 C63
I came back to report
So the first time, I managed to track down a spark plug socket finally that would fit. Had a look and it all looked fine, the engine light came back on after my last post finally today. Similar situation as last time, and the same pending misfire to cylinder 1, 2, and 5 came up.
I swapped the coils around and see if it moves with the coil.
So, has anyone tried the non OEM Coils?
So the first time, I managed to track down a spark plug socket finally that would fit. Had a look and it all looked fine, the engine light came back on after my last post finally today. Similar situation as last time, and the same pending misfire to cylinder 1, 2, and 5 came up.
I swapped the coils around and see if it moves with the coil.
So, has anyone tried the non OEM Coils?
03-14-2018, 04:07 PM
#5
Member
I was getting p0300 code with bunch of specific cylinder misfire codes recently and it turned out to be a bad O2 sensor. Since replacement it has been fine.
