Toubleshooting Engine Misfire
Thread Starter
Member
Joined: Oct 2014
Posts: 247
Likes: 0
From: LA, CA
'11 c63
Toubleshooting Engine Misfire
>On cold starts, my engine would vibrate really bad.
>The misfires goes away after it gets warmed up for a few minutes
>Eventually the CEL came flashing, then stayed on permanently
>I used the Torque Free App and it gave code P0303 (Cylinder 3 Misfire Detected) and P0003 P0703 P0800
>i swapped the ignition coil and spark plugs between Cylinder 2 and 3
>i noticed #3 was dry, but #2 had oil all around the threading
>engine still shows CEL and pulls the same codes P0303
I already knocked out the spark plugs and ignition coil, and I was working on my car right before all this happened, so i could have knocked something loose.
>I purchased Techron Pro-grad (the diluted one) and the misfires hasnt happened yet (maybe I haven't let the engine cool down enough for a cold start), but CEL is still on. I have a bottle of the Techron concentrate ready for my next fuel up
>I purchased Torque app for 5 dollars last night, and this app is showing P0300 (random cylinder misfire), P030X (every cylinder but #5). It was showing P0300, and every P030X under pending fault codes on the free app
Could this be an issue with the fuel filter, spark plug wires, MAF/MAP, and/or O2 sensor?
>The misfires goes away after it gets warmed up for a few minutes
>Eventually the CEL came flashing, then stayed on permanently
>I used the Torque Free App and it gave code P0303 (Cylinder 3 Misfire Detected) and P0003 P0703 P0800
>i swapped the ignition coil and spark plugs between Cylinder 2 and 3
>i noticed #3 was dry, but #2 had oil all around the threading
>engine still shows CEL and pulls the same codes P0303
I already knocked out the spark plugs and ignition coil, and I was working on my car right before all this happened, so i could have knocked something loose.
>I purchased Techron Pro-grad (the diluted one) and the misfires hasnt happened yet (maybe I haven't let the engine cool down enough for a cold start), but CEL is still on. I have a bottle of the Techron concentrate ready for my next fuel up
>I purchased Torque app for 5 dollars last night, and this app is showing P0300 (random cylinder misfire), P030X (every cylinder but #5). It was showing P0300, and every P030X under pending fault codes on the free app
Could this be an issue with the fuel filter, spark plug wires, MAF/MAP, and/or O2 sensor?
Super Member
Joined: May 2011
Posts: 918
Likes: 21
From: NYC
2017 C63S coupe '09 C63, '15 Durango RT, '14 Jeep SRT8
>On cold starts, my engine would vibrate really bad.
>The misfires goes away after it gets warmed up for a few minutes
>Eventually the CEL came flashing, then stayed on permanently
>I used the Torque Free App and it gave code P0303 (Cylinder 3 Misfire Detected) and P0003 P0703 P0800
>i swapped the ignition coil and spark plugs between Cylinder 2 and 3
>i noticed #3 was dry, but #2 had oil all around the threading
>engine still shows CEL and pulls the same codes P0303
I already knocked out the spark plugs and ignition coil, and I was working on my car right before all this happened, so i could have knocked something loose.
>I purchased Techron Pro-grad (the diluted one) and the misfires hasnt happened yet (maybe I haven't let the engine cool down enough for a cold start), but CEL is still on. I have a bottle of the Techron concentrate ready for my next fuel up
>I purchased Torque app for 5 dollars last night, and this app is showing P0300 (random cylinder misfire), P030X (every cylinder but #5). It was showing P0300, and every P030X under pending fault codes on the free app
Could this be an issue with the fuel filter, spark plug wires, MAF/MAP, and/or O2 sensor?
>The misfires goes away after it gets warmed up for a few minutes
>Eventually the CEL came flashing, then stayed on permanently
>I used the Torque Free App and it gave code P0303 (Cylinder 3 Misfire Detected) and P0003 P0703 P0800
>i swapped the ignition coil and spark plugs between Cylinder 2 and 3
>i noticed #3 was dry, but #2 had oil all around the threading
>engine still shows CEL and pulls the same codes P0303
I already knocked out the spark plugs and ignition coil, and I was working on my car right before all this happened, so i could have knocked something loose.
>I purchased Techron Pro-grad (the diluted one) and the misfires hasnt happened yet (maybe I haven't let the engine cool down enough for a cold start), but CEL is still on. I have a bottle of the Techron concentrate ready for my next fuel up
>I purchased Torque app for 5 dollars last night, and this app is showing P0300 (random cylinder misfire), P030X (every cylinder but #5). It was showing P0300, and every P030X under pending fault codes on the free app
Could this be an issue with the fuel filter, spark plug wires, MAF/MAP, and/or O2 sensor?
Thread Starter
Member
Joined: Oct 2014
Posts: 247
Likes: 0
From: LA, CA
'11 c63
oh ok, was going to ask if it was safe to drive on since ive been doing it all week but it seems like you did too. i'll try and empty the tank then try different gas
i do have fidelity warranty and have it scheduled for the stealership next week but i fear them rejecting my warranty lol trying to see if i can save the money and hassle myself
i do have fidelity warranty and have it scheduled for the stealership next week but i fear them rejecting my warranty lol trying to see if i can save the money and hassle myself
Super Member
Joined: May 2011
Posts: 918
Likes: 21
From: NYC
2017 C63S coupe '09 C63, '15 Durango RT, '14 Jeep SRT8
oh ok, was going to ask if it was safe to drive on since ive been doing it all week but it seems like you did too. i'll try and empty the tank then try different gas
i do have fidelity warranty and have it scheduled for the stealership next week but i fear them rejecting my warranty lol trying to see if i can save the money and hassle myself
i do have fidelity warranty and have it scheduled for the stealership next week but i fear them rejecting my warranty lol trying to see if i can save the money and hassle myself
Thread Starter
Member
Joined: Oct 2014
Posts: 247
Likes: 0
From: LA, CA
'11 c63
i have my secondaries removed, im seriously hoping its not my cat bcuz its one of the few things my warranty doesnt cover. I just cleaned my MAF sensor, check engine light still on.
think the last few remaining things is a loose connection somewhere, o2 sensors, bad fuel, or an air leak somewhere.
think the last few remaining things is a loose connection somewhere, o2 sensors, bad fuel, or an air leak somewhere.
