Any thoughts on why engine riding rough? - The Unofficial BMW M5 Messageboard (m5board.com)

Greybeast · 8th January 2007, 05:03

On my way home from work this morning, my car suddenly began to run rough at about 50% power. The best way to explain it would be this:

I used to have a big block Chevelle whose #5 spark plug wire used to pop off the plug, leaving the car to run on 7 cylinders. This felt exactly the same.

The check engine light came on.

Whole thing lasted about 10 minutes then resolved and light is now off and car runs fine.

Thanks,

Greybeast

CEC · 8th January 2007, 05:24

Get a code reader and find out what code was triggered.

EM5PWR · 8th January 2007, 06:33

Could be a CPS ...

Polynova · 8th January 2007, 08:59

Get a code reader and find out what code was triggered. x2

If it were in limp mode you need to turn off /re start the engine to re-set to normal operation.

maxm5 · 8th January 2007, 14:49

Mine did a similar thing recently - Turned out to be a CPS. Did your exhaust note change as well?

Greybeast · 8th January 2007, 18:41

No exhaust note change aside from the sputtering. I guess Peake is the way to go for a code reader?

gsfent · 8th January 2007, 23:19

Quote:

Originally Posted by Greybeast

No exhaust note change aside from the sputtering. I guess Peake is the way to go for a code reader?

Good idea. Another vote for CPS. If no exhaust sound change noted, more likely intake.
Regards,
Jerry

jjc1843 · 8th January 2007, 23:32

Greybeast:

The Peake Code Reader is invaluable for diagnosing the beast. If you want to stop over and use mine, PM me.

kcwrx02 · 8th January 2007, 23:40

Maxm5, did you replace your CPS and the problem went away? mine too has recently started throwing codes. Exhaust note changes but there is still power.
I get P3808 BMW FC Code (08) Intake Camshaft Position Sensor , Bank 2

after that, i get some vanos faults probably caused by the CPS fault.

Quote:

Originally Posted by maxm5

Mine did a similar thing recently - Turned out to be a CPS. Did your exhaust note change as well?

psunitlions1 · 9th January 2007, 08:04

had it happen and car felt sluggish. it tripped the SEs light. Dealer said that a saprk plug failed. but uponinspection of said plug things are fine.

then but a half month later same thing happened..havent taken it to a dealer yet as when I turned the car off it seemed back to normal

tripped when in 3rd at high rev around 5500 to 6000 and rode it for like 20 seconds but let off the gas it then tripped

dont know what that means

any fixes outside a new set of plugs?