Last night I was on my way home from dinner with a friend. There's a really nice tunnel that makes the muffler delete sound just wonderful so I decided to open it up a bit (this was well after the car was completely warmed up). I started out at 45 mph in 2nd gear and went to probably 80 in 3rd when I felt a loss of power and the car started running really rough. At that point the SES light came on for a bit and I could still feel it being rough. I slowed down and eventually the light turned off and it smoothed out.
At the next street I pulled off and pulled the codes. I got a bunch of misfires. Here are the codes:
I'm guessing C7 is the one that was causing the problems. So, I cleared the codes and continued on my way home. During the drive home it felt really low on power. So, I parked it and let it sit for a few hours.
Early this morning I took it out for a drive. I did the same thing -- going through 2nd and 3rd. It felt considerably stronger, but it didn't feel like it was exactly 100% (though it's probably hard for me to tell... I've been driving the M5 every evening this week after only driving my Honda for a couple weeks). The LPH cluster test came up with about 127 (after correction) during these pulls. The maximum LPH number I've had with the car was about a month/500 miles ago and I want to say it was around 140. I also noticed that the coolant temperature stayed around 73 to 74 degrees Celsius while cruising at 70 mph on the highway.
In the last 15,000 miles or so my car has had the following parts (that I've found generally lead to trouble) replaced:
I've also heard that sometimes our cars just do a random misfire every once in a while but after clearing the codes and letting it run a bit all is well. I just don't want to find out the hard way that I ignored something serious. I've also found that some days my car feels more powerful on the butt dyno than others... That feeling might be inaccurate, though, since I daily drive a slow (but fuel efficient
) Honda, and the M5 is, of course, going to feel quick after two weeks of driving the Honda.
Thanks.
James
At the next street I pulled off and pulled the codes. I got a bunch of misfires. Here are the codes:
- Cd - Misfire during warmup, cylinder 1
- CF - Misfire during warmup, cylinder 3
- D0 - Misfire during warmup, cylinder 4
- D1 - Misfire during warmup, cylinder 5
- D2 - Misfire during warmup, cylinder 6
- D5 - Misfire during warmup, multiple cylinders
- C7 - Misfire, cylinder 4
I'm guessing C7 is the one that was causing the problems. So, I cleared the codes and continued on my way home. During the drive home it felt really low on power. So, I parked it and let it sit for a few hours.
Early this morning I took it out for a drive. I did the same thing -- going through 2nd and 3rd. It felt considerably stronger, but it didn't feel like it was exactly 100% (though it's probably hard for me to tell... I've been driving the M5 every evening this week after only driving my Honda for a couple weeks). The LPH cluster test came up with about 127 (after correction) during these pulls. The maximum LPH number I've had with the car was about a month/500 miles ago and I want to say it was around 140. I also noticed that the coolant temperature stayed around 73 to 74 degrees Celsius while cruising at 70 mph on the highway.
In the last 15,000 miles or so my car has had the following parts (that I've found generally lead to trouble) replaced:
- MAFs
- Bank 2 exhaust CPS
- O2 sensors
- Fuel pump
- Spark plugs
I've also heard that sometimes our cars just do a random misfire every once in a while but after clearing the codes and letting it run a bit all is well. I just don't want to find out the hard way that I ignored something serious. I've also found that some days my car feels more powerful on the butt dyno than others... That feeling might be inaccurate, though, since I daily drive a slow (but fuel efficient
Thanks.
James