Right around the late 90’s BMW decided, for some reason, to change the ‘Check Engine’ light to read ‘Service Engine Soon’. One problem I have found on the consumer level is that most people see ‘Service Engine Soon’ and feel as though it is time for an oil change, which makes sense. Check Engine has been the standard for years throughout the automobile industry, so I’m not quite sure why they changed it, and I’m not going to call and ask.
Through my years of BMW Service in San Diego, I’ve found customers trying to do all kinds of stuff to get this light off. They disconnect the battery, take their gas cap on and off, turn the car on and off a bunch of times, and I’ve had one customer go as far as trying to take the bulb out. While all of these efforts are fun to hear about, they’re all futile.
The truth is there are over 20 different reasons why your ‘Service Engine Soon’ or ‘Check Engine’ light is on. If the car feels fine and nothing seems different, don’t just keep on truckin’, get it checked out. Many people won’t, mostly due to the fact that 1. It’s a hassel to go to the dealer and schedule an appointment, drop off the car and then find out you forgot to tighten the gas cap. 2. it’s expensive! Most places will charge you an hour of labor just to read out the problem and explain it to you. In San Diego that translates into anywhere from $85-$130 for no repair, just information. We offer it as a free service in our BMW Service section of the website.
At our BMW Service center in San Diego we check this for free, mostly because we are too lazy to go through all the billing process. I can get the computer on your car and have the reason the light is on within 2 minutes. If I bill you and hour for those 2 minutes, it’s really not fair and pretty rude. It also means that I have to take about 15 minutes to get all of your personal info, your car’s personal info, enter it into the computer, and . . . . screw it, I like 2 minutes better!
Here are some common reasons why the light may be on, on BMW’s built after 1997:
1. Gas Cap not secured or no longer sealing
2. Camshaft Sensor broken
3. Thermostat may be broken
4. Any sort of vacuum leak
5. Automatic Transmission issues.
Notice how a bad Oxygen Sensor didn’t make my list. Of all the ‘Service Engine Soon’ lights I’ve diagnosed on cars built post-97, I’ve almost never had a bad oxygen sensor — yet many shops, like ‘Joe’s Fix All’ seem to be finding them bad all the time. If you are told this on say a 2002 530i, be skeptical and start thinking about going elsewhere as they either do not have the proper diagnostic computer or they aren’t processing the info in their brain properly.
Happy driving and DO NOT ignore that light!! While in most cases the light won’t cause your car to self-destruct leaving you in the middle of the desert at 2am, you do want to know what’s going on and don’t want it to lead to more costly repairs.
5836 Autoport Mall
San Diego CA 92121
Hello Chris and really thank you for this post! I’m from Romania and I searched all over the rumanian websites about this problem but I didn’t find something more specific than your review. Thank you very much in the name of..many people I guess!
Your post for : Check engine soon- now what –was most useful.
I was one of those people who took it in for a diagnosis and was charged $180. They simply read off all the codes and gave me a shotgun estimate to fix everything. It’s a 2000 Z3 and cost more than the car is worth. I said no thanks and have been living with the light. BUT as with one of your reasons- I suspect the thermostat is broken in the open position. It never warms up since the light is on. How much do you charge to replace the thermostat?
I think it might be worth me to drive 50 miles for an honest mechanic. Thank you, H. Mike Collins