Engine Light

[cordovar]

hey guys, quick question. My engine light came on and BMW told me that if i use high octane fuel in the winter it will send a miss fire code to the puter and make the engine light come on. they recomend mid grade octane for the winter. has anyone else experienced this. or is it bull.

thanks in advance

cheers

[UCrewX5]

That's an original explanation. I would ask them what the code was that set off the engine light. I'd also seek a 2nd opinion.

[JCL]

I have heard the mid-grade recommendation in cold climates from BMW more than once.

Can't say for sure that this was what caused your misfire, but yes, high-octane fuel is harder to light up, and thus more prone to misfire, and a tank of 89 could make a difference.

Go back to the 91 when the weather warms up. No, the 89 can't hurt your vehicle. If you are experiencing any misfire, you will get better mileage on the 89, and the power difference won't be noticeable.

[cordovar]

thanks a lot guys for the info. i will give it a try

[Dr. T]

Tell me you weren't using Petro Can. gas Makes all my vehicles run like garbage.

I'm currently using Sunoco 91 in my `06 X3 3.0i in Mississauga w/o any problems. I think the dealer is full of it on that observation. More probably, you didn't have a proper seal on the gas cap...known to set-off CELs...

[rayxi]

Petro-Canada puts (more) ethanol in their gas in the winter. This could be a cause of the problem. Try a tank or two of premium from Shell or one of the other brands that don't add ethenol.

[cordovar]

i used 94 octane sunoco. The light comes on when its below 10 deg. then after a day it will go off. and its not the gas cap i checked. lol

[rayxi]

I believe Sunoco Ultra 94 is ethanol enhanced. I use Shell V-Power which 91 octane and never had a fuel related problem.

[Whoats]

My engine light came on in Dec.

I use that crappy Petrocanada gas, no it's not the gas. I use premium only, and never had a miss fire until I started it one cold morning -30C ( -20F) and it miss fired and ran rough from then on. I phoned Edm BMW ( where I leased it from ) and they had my X3 up on hoist in 3 hours(very impressive)


Well after few minutes on the machine, the mechanic came over and told me # 2 cylinder spark plug was misfiring. They replaced all 6 pugs and had me out on the road in an hour. I had a chance the quiz the tech who worked on my X3 and he told me on the Q/T Bosch plugs BMW uses are crap, in fact I was the 3rd one that month with a bad plug. It seems when uber cold, then heated up they tend to crack.

[xx3]

My Service Engine Soon light has been coming on intermittently lately.

Under hard acceleration (like on the freeway in 4th or 5th gear) the acceleration isn't smooth (a little jerky). My friend said not to use Shell gas (which I switched from) and the problem (and the SES light) went away for a little bit... now the light and the same behavior is back.

Thing is I live in the bay area, and the coldest it ever gets here in the mornings is 40-41?F (and even thats rare).

I only use 91 Octane. Same problem you guys think?