CHECK ENGINE is causing me problems

Hi Everyone,
Today I was driving around and suddenly my 'check engine' light came on. I was very suprised, so I immediately pulled over just to see what I could see. Everything seemed normal... Decided to drive it home, and about 10-15 min. later the 'check engine' light went off... This happened to anyone before? Whats going on?!

my check engine light is always on and never goes on. My car is fine though i think it is just a sensor that went bad so it says your engine needs to be checked.

Yeah, That's what I figured... BTW, thanks for being the first person ever to reply to a question I've asked. Are there any better forums than this?!

I did have this problem twice before. Experienced dealer always asked me one question first, " you just pumped the gas lately? "
If the answer is yes, then it must be the gas cap problem. Make sure it is tightly closed. When air goes in, that can cause the check engine lights on. After checking, it will go off one or two days later. If not, then that must be something else.

^_^

i don't know of any other forums but i think that i am going to find one because no one has responded to my questions either.

Pency
Thanks a lot! I guess it may very well have been from the gas. That or a wack sensor. I'll be sure to keep that in mind and pass it on to anyone else who asks.

I just picked up my 97 328i last Friday. What an amzing car! The next day I started out on a road trip, and I all of a sudden, the check engine light comes on! This can't be happening! I've had the car for less than 24 hours!!! I pulled over, called the dealer, and as mentioned in the other reply, I was asked, "did you fill up?"
"Yup"
"You used low grade gas didn't you?"
"Maybe"
"When it goes down to half tank, fill it back up with the highest octane gas available. It should sort it self out."

The dealer suggested that the O2 sensor was probably getting a funny reading. So out of habit I put the cheap stuff in the car. I know better for next time.

So all of this just to say, it might be bad gas.

Cheers!

So is low grade gas actually bad? Cus I put in 89 octane, and Im at high elevation (rockies) which makes the 89 more like 91... Does low grade hurt the engine?

I put in 87. As I was filling up I saw the label on the gas cap cover which stated 89 is the minimum. It was a bit too late as I was pretty much finished filling up.

Since you put in 89, octane may not be your problem. Although I suspect that there can be variablitiy in the level (+/-) of octane content.

I'm curious. Does anyone know if there is a way to get the engine fault codes, without having to purchase a special interpreter?

Cheers!

Go here for info on how to check the error codes.

http://www.bimmerinfo.com/bmw_flash_codes.htm

Use this procedure to see if your lambda sensor is doing the lambada.

cheers,

'86 325 :wave:

Unfortunately, I'm not so lucky. DMEs using motronic versions above M3.x (model years 95 on) do not allow access to fault codes through the Check Engine light.

Source:
http://www.unofficialbmw.com/repair_faqs/motronic.html