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

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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!
 
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!
 
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.
 
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.
 
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.
 
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?
 
joeblow said:
. . . 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
 
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.
 
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.
 
joeblow said:
because we are high in the mountains and far from everything. For me, cold soaking seems to be the smoking gun.

I have issues with starting in sub-freezing temperatures. What are the temperatures like around where you are, also what's your elevation? I'm at around 6000 feet (in Utah). I use ethanol-free too, but switched from 91 octane to 88 octane- it seems to start easier now, though I'll go back to 91 this summer. I almost wonder if the REx's ECU doesn't put enough of a 'choke' (it's not carbureted, but think about the fuel injection analog) on the fuel system when starting in cold temperatures, which is why we have this problem. Right now it's 15F, though my car has been sitting in the garage.

EDIT: I should mention that I did get my REx started without any drama today.
 
Sounds like we may be neighbors. I am at 7000ft in Kamas, Utah. Are you in Park City? My wife works at St. Regis and after working a night shift and leaving it cold soaking in the employee parking lot on the Jordanelle side, the REX will not start sometimes. Also going to the movies and then trying to start on the way home we have had issues. Obviously we are talking -10deg sometimes so it is cold. We have been using 91OCT ethanol free but I am starting to think we should go with the 88OCT with ethanol which should start easier. Heck the more ethanol the netter if light off is the issue. E85 might be even better?
 
joeblow said:
Sounds like we may be neighbors. I am at 7000ft in Kamas, Utah. Are you in Park City? My wife works at St. Regis and after working a night shift and leaving it cold soaking in the employee parking lot on the Jordanelle side, the REX will not start sometimes. Also going to the movies and then trying to start on the way home we have had issues. Obviously we are talking -10deg sometimes so it is cold. We have been using 91OCT ethanol free but I am starting to think we should go with the 88OCT with ethanol which should start easier. Heck the more ethanol the netter if light off is the issue. E85 might be even better?

Unfortunately, I do not live in Park City though I visit often and am very familiar with the area (we rent a house or condo for a month during the summer there-escape the valley heat). I live up at the top of the Bountiful bench, so my elevation is more like ~5500 rather than 6000, I rounded up to make a bit of a point. The recent snow storm left me unable to go anywhere on Wednesday, and when I did drive down on Thursday, there was definitely a bunch more up at our house than down by I-15. I've been to a couple of receptions at the St. Regis, though always from the Deer Valley side. In the valley there are more fuel options, I can get ethanol free in both 88 and 91 octane varieties. I'm not sure how E10 affects winter starting, but my guess is that it might make it easier, it seems like most of the mainstream gas stations around here have winter-mix fuel which has additives for cold starting.

Once I get the REx engine running, I'm home free. I can even clear the check engine light, and it will not come back on... until the next cold soak start. If you get stuck somewhere where the REx isn't wanting to start, try the emissions testing mode (http://www.mybmwi3.com/forum/viewtopic.php?t=2075). The great thing about this is you can attempt to start it multiple times with that, where as when doing normal driving with the REx, it only tries once to start.
 
We were in the SLC Avenues until 4 years ago when we moved up the hill to escape the inversion.

I got my Bluetooth OBD2 port dongle to work with my Tourqe Pro app on my phone so I can clear the codes on the fly and keep retrying the REX till it starts. The process is a little finicky and the wife is not patient enough for it. If it happens to her she is less likely to get it going for that reason.

I am going to go with low OCT ethanol fuel on my next fill up and try that out. I think it is the easiest to try before going more extreme.
 
So another update. It has been very cold with storm after storm dumping lots of snow. Having switched to low octane fuel with 10% ethanol from super ethanol free our REX start issues seem to be resolved. We have seen no difference in the charging ability of the REX with the lower octane fuel either. So it would seem this 'fix' is working for our car so far.

Hope this might help others in cold climates with REX starting issues.
 
So another update. It has been very cold with storm after storm dumping lots of snow. Having switched to low octane fuel with 10% ethanol from super ethanol free our REX start issues seem to be resolved. We have seen no difference in the charging ability of the REX with the lower octane fuel either. So it would seem this 'fix' is working for our car so far.

Hope this might help others in cold climates with REX starting issues.
 
How do you use the Tourqe Pro app to restart the REX? Do you just clear the error codes and then it automatically tries again, or is there more to it?
 
arodi3 said:
How do you use the Tourqe Pro app to restart the REX? Do you just clear the error codes and then it automatically tries again, or is there more to it?

Yes, that's it. Just clear the codes so the car will allow the REX start attempt again.
 
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