Car went into limp mode :( - The Unofficial BMW M5 Messageboard (m5board.com)

Serge · 19th December 2001, 07:28

I was driving down to the states today when this happened. After I pass throught the US customs, the road emptied out and I went WOT on third up to redline then backed off in fourth. 5 mins later, I repeated the same thing but this time at 6600 rpm the service engine soon light(the square-like orange light for us Canadians) came on and the car feels like hitting the rev limited at that point. I immediate let off the throttle and the car went into limp mode. I had trouble sustained normal highways speeds so I pulled off at the next exit. Half way through the exit, the light went off and the car went into half-limp mode where I can maintain normal highways speeds without the car shaking but there's noticable powerloss. I got to Bellingham and went inside the mall for an hour. Came back out, started the car and everything is normal again...

Does anyone knows what wrong? Or anything?

greg · 19th December 2001, 08:32

Probably a bad load of gas. whne you oushed the car it was getting more preignition than the computer could handle. Happened to me once when I inadvertently filled up with 87 octane. If the engine seems back to normal and the light stays off don't worry about it.

VanCooper · 19th December 2001, 09:25

Samething happenned to me In Washington state too, the car was making a tottaly different exhaust note and I could barely accelerate. What I did is that I took the next exit, shut off the engine and re-started it and it came back to normal...It wasn't the first time it happened though

rvacha · 19th December 2001, 13:35

I had a similar thing happen to me in my 540i, except that my check engine light had come on a couple of days beforehand. Under close to WOT, the Check Engine light would go from constant on to blinking and the car would immediately switch to limp mode. According to my dealer, the blinking indicates that the DME could not even get close to normal emissions ranges, which in turn usually implies a condition that could damage the engine. In my case, it turned out to be a failed cat (the second failure in 65K miles). Cats are a fairly common BMW V8 problem, so odds are fairly good it is your problem as well. Definitely take it to the dealer, who should be able to read the OBC fault codes and determine the problem quickly. Good luck!

AndyMenard · 19th December 2001, 14:08

Could be a host of different things... one of which is a possible bad cam sensor? If this starts happening every time you drive? I would pull into the dealer and have them pull up the event log from the OBD Computer and it will tell them if one of the cam sensors is going bad? I just had one of mine replaced recently. It was going in and out of limp mode every time I drove it.

Replaced the bad sensor and she has been fine since.

Just another thing to check.

fais2000 · 19th December 2001, 18:07

yep
had the exact same limp problem, viagra did the trick... ooops sorry wrong board

,

yes, i have that problem also. I had a bad tank of gas and i am sure of it, the attendant put in 87 octane. I would suggest get yourself a new tank of gas asap, and dont worry, no harm done to the car. Also make sure you either dont go back to whever you got your gas from, and/or complain.

fas

Serge · 19th December 2001, 21:14

Thanks guy for your inputs. Actually, I didn't get gas at all while I was in WA cause they didn't offer 94 octane. I doubt it is bad gas cause I only happened there once and didn't happen again. I am worried now it's a bigger problem-->cam sensor or the cats. You wouldn't have to push the car to find out right? I haven't pushed the car since and it didn't go into limp mode.