The Service Engine Soon light won't go out. I've had it checked for intake leaks and reprogrammed.

Once the system is reset, and the light switched off, I get about 40 miles of driving before the light comes back on.

No other issues with driving or performance. Anyone else have experience with this? I have a good shop working on it thankfully.

 

Have your shop read the code. That will point you in the right direction.

Nik

 

High methanol content will upset the knock sensor. Knock sensors don't like to be upset. If that turns out to be the issue, visit http://www.toptiergas.com/retailers.html

 

I seem to have the same problem. I took it to the dealer and they said that it was the knock sensor. Will using the approved fuel listed on the site you provided slowly begin to fix this problem? Or am I too far gone and I have to get a new sensor installed?

 

If the error code is in fact a fuel factor I'm surprised the shop didn't mention the BMW top tier list. If the sensor isn't permently damaged the next tank should be OK. Lots of things can trip a CEL code though. I did have to have mine replaced not knowing the station I always used had snuk in methenol laced fuel. Good luck.

 

Same thing just happened to my 2004 (R50) on the way home from work today - no warning, no obvious engine issues, just saw the "Service Engine Soon" light come on. Checked the oil, the fuel filler cap and the air filter when I got home - all seem fine.

I'll probably have it checked out this weekend, but if the fuel thing turns out to be the issue, would the light shut off on its own or do I still have to get it reset? Reason I ask is because I'm about to fill up again tomorrow anyway, so I'll just get the really good stuff at Shell or Conoco and hopefully avoid paying for a service visit if I can.

I should note that I live in Colorado, where our fuel contains up to 10% ethanol by law (it's supposed to improve emissions performance).

Also, would it make any difference to throw in a bottle of fuel system cleaner (probably the good stuff that Lucas makes) while I'm at it?

 

I have started putting "Top Tier Gas" in my R52 and after a couple of fill-ups the service engine light has almost completely gone away. It still comes on when my tank gets low, but I am guessing that that is due to separation of the different gasses. Note that it will probably take a few tanks before the light starts going away.

If it is in fact your knock sensor then you can give this a try. Make sure that you take a look at the list that Fly'n Brick provided because there are a lot of gas stations that I expected would be on there but aren't (such as BP). I hope it works for you!

 

Thanks for the info. I'm guessing it took a few tanks to get here anyway - up to this point, I've been using the grocery store's pumps thanks to the nice discount they give when you buy food there. So three tanks of that over my ownership (I've only had Jubilee a month and a half) probably made the difference - just about when I hit the 1/4 mark today, the light came on.

Shell, Conoco and Phillips 66 are all readily available in my area -and I think some local Shell stations actually support the grocery-store discount, so I'll have to seek them out now to save that extra few cents per gallon.

 

I was doing the same thing. Didn't take long for it to trigger the CEL. Had it reset but didn't change habits. A few tanks later, CEL, but this time had to have the sensor replaced but by an idependent shop who was nice enough to educate me on the varieties of fuel qualities. Haven't seen that little light since except after some really hard mountain driving last year with long down hill, high RPM moments. Don't remember what the code was but no big deal and Schomp reset it.

 

Are you burning 91 octane?

 

Nothing but. Once in a while I stumble upon 92 and the li'l fella just trips out, Haight-Ashbury all over again.

 

Nothing but 91-octane premium in my case, yes.

To update my own situation, I filled up with a tank from Shell yesterday and added a bottle of Lucas "Deep Clean" fuel treatment. The light stayed on during my drive over to visit family last night, but was off for the entirety of my drive home.

Thinking I had figured it out, I was surprised while running an errand today when the light came back on again, not long after the engine came up to its regular temp level. :shrug: Again, everything sounds and feels normal. I'll wait it out, I guess.

 

Hence why I'm actually excited to travel through the Midwest in a couple of weeks, where the altitude is lower and the octane's a little higher. The extra humidity can't hurt either, I guess.