New to me 15' REX Certified Pre Owned no start REX?

[joeblow]

Thanks guys, I assume I was in accessory mode and that is why the heat did not work.

[joeblow]

OK I picked the car up yesterday with the following diagnosis and repair:

Spark plugs and coils faulty. Full engine diagnostic including compression test (220PSI) and else checked good.

They even left the coding I had done so after leaving I engaged the REX SOC and it worked as it is supposed too! Very happy!

[joeblow]

Well drove the car on a long trip the other day and when we needed the REX to do a SOC, it would not run and we got an error message and a CEL. I immediately pulled off the highway before I passed the last charging option and plugged in to a level 2. While charging I started to look at the issue. This time I was prepared though and was able to scan the issue and found 'CYL #1 missfires'. So I cleared the CEL and after sufficient charge to get me the rest of the way home I unplugged and headed out. I hit SOC and the REX fired right up and ran all the way home.

I am starting to wonder if this is just a fuel issue. The car was from California and with the low miles on it, 14K, I am guessing it got little use. For all I know the REX never even got used. So taking that possibility of really old fuel plus the fact that California does not have winter blend and I am at 8000ft in the Utah mountains at -7 deg, I am burning off the tank and refilling. I am going to add some seafoam to the fill up too. So far the REX has fired up every time, so that may have been the issue. I also found a nice 2 gal can that fits the front trunk well for double back up!

[MKH]

I use Power Research PRI-G gas stabilizer. Will maintain the fuel for years. This is what we used exclusively in the Military in back-up generator fuel tanks, and emergency fuel storage, which might see only limited use over two-three years or more.

[joeblow]

In my case I will have to use the REX fairly regularly due to our remote location. The closest charging station from us is 30 miles away. So I am not overly concerned with the fuel staying fresh going forward. I just bought a bottle of Techron fuel system cleaner to start and will condition ongoing with Lucas fuel conditioner and lubricant to keep it going strong.

So far with fresh fuel it has not hiccuped once.

[slac10]

You should change the fuel pump relay under the glove box. My i3 had the same problems until I changed it myself.

Never had a problem since the. The relay cost roughly $35.

[joeblow]

Well the REX hiccuped again. Would not start for my wife in very cold night sitting outside. She did not pre-condition but not sure that would have helped the REX. So she got the CEL engine light and no start, made it home but barely. Scan shows misfires on #1 and #2. After a warm night in the garage and me clearing the codes it started up fine.

Starting to look like a cold weather thing. I guess the fuel relay could be hanging when cold and not getting fuel to the engine but I would think it would set different codes than misfires? I might try lower octane fuel too which should be easier to light off when cold then switch back to high obtain in the summer months?

Any thoughts?

[bwilson4web]

. . . After a warm night in the garage and me clearing the codes it started up fine.
. . .

Any thoughts?

We are finding a similar pattern. If you get an error, use BimmerLink to clear the codes and let the car power-cycle, ~20 minutes off. Then try again. If there is a permanent error, it will be in the error log. If not, the car starts and runs normally. No need to make a service department "boat payment."

Bob Wilson

[jadnashuanh]

FOr some people, the gas will sit in the tank, unused for a very long time. While the system is reasonably well sealed, I wonder if it's losing its more volatile components over time, or, if you're in an area that uses 10% ethanol, the fuel quality itself is to blame.

If you can buy fuel without ethanol in it, try that. I can't in my state. Also, you might try a fuel stabilizer unless you're filling up the tank on a regular basis.

[joeblow]

Fuel age is NOT an issue for me nor is ethanol as I buy ethanol free and use the REX often because we are high in the mountains and far from everything. For me, cold soaking seems to be the smoking gun.