Need to pump wrong octane fuel from tank

[bmwm3s65]

Hi, I wasnt paying attention at the fuel pump, forgot to select 93 and the pump automatically defaulted to 87 and i completely filled the tank with 87.Now I want to pump out all the fuel out of the tank. I did a search and found that best way to do this is to use a tool such as a bt tool, inpa, ista, protool, etc. I cannot find anyway to prime/control the fuel pump in inpa or protool. I do not want to have to open the fuel tank to pump it from within the vehicle. Does anyone have a confirmed way to activate the pump by sending a message through the ecu?

[CamasM3e93]

If you aren’t supercharged or running a tune you should be ok. Your mileage may vary but the car with stock tune is set up to adjust for low octane fuel.

Other options:

You can add octane booster. You would need to add enough to raise your octane 60 basis points which is usually 3 small bottles for 20 gallons assuming you filled from empty.

Others have disconnected the fuel rails, removed an injector, and actuated the pump to ‘on’ by toggling the ignition to On without starting the car (keep foot off brake and clutch). What a mess though, 16.6 gallons of fuel. Yikes

Personally if I felt strongly about emptying the tank I would pull up the back seat, and open the fuel pump and fuel sender ports (you need a $20 tool or a hammer and tap and patience) and pump the gas out with whatever device you wanted to use. A $5 fluid transfer hand pump would do the job.

[Drv4fun]

How about an octane booster?

[bmwm3s65]

I understand , that if i drive easy the ecu should adjust, however, i already paid 25k to replace my engine because my mains failed on my old engine, so i cannot take any chances. I believe I would need a lot of octane booster to make any discernable difference and that it could possibly foul the plugs. based on this i rather just figure out how to pump the gas out. I am hoping to find a way to do this through software if possible.

[CamasM3e93]

Originally Posted by bmwm3s65

I understand , that if i drive easy the ecu should adjust, however, i already paid 25k to replace my engine because my mains failed on my old engine, so i cannot take any chances. I believe I would need a lot of octane booster to make any discernable difference and that it could possibly foul the plugs. based on this i rather just figure out how to pump the gas out. I am hoping to find a way to do this through software if possible.

Well, come back and let us know how it works out. For what it is worth, I intentionally filled up with 87 octane in Fossil, Oregon because it was the only option for 75 miles - adding Lucas Oil octane booster as I described. I'm harrop supercharged - it was ~80F outside which means IATs were 110-120F with spirited driving - no issues.

The fuel pump puts out 4-6 bar of pressure. That's 60-90 PSI. While that's considered 'low pressure', that's a lot of pressure for gasoline coming out of a 3/8" orifice. Whether you turn the pump on with software or some other means - you've got a potential mess on your hands. If you've seen the movie Zoolander......

[DrFerry]

Originally Posted by bmwm3s65

I understand, that if i drive easy the ecu should adjust, however, i already paid 25k to replace my engine because my mains failed on my old engine, so i cannot take any chances. I believe I would need a lot of octane booster to make any discernable difference and that it could possibly foul the plugs. based on this i rather just figure out how to pump the gas out. I am hoping to find a way to do this through software if possible.

You could also siphon the gas out of the tank. Sorry to hear about your S65 main bearings failing. Just out of interest, what does it sound like when the S65 main bearings are failing? I'm thinking it's a different noise to rod bearing knock? Or is it?
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[Redd]

Just use octane booster. Just be careful of the labels on the bottle - 1 octane point is only 0.1 octane number. Some boosters add 3 octane points (0.3 octane), some add 3 octane numbers (3 octane). You gotta know the difference.

I use Bardahl which raises 3 octane numbers per bottle for 60L. So 2 bottles of Bardahl octane booster will make your 87 into a 93. I've been using it alternate full tanks with no issues so far, but I wouldn't recommend it for long term use if you have cats.

[bmwm3s65]

Originally Posted by DrFerry

You could also siphon the gas out of the tank. Sorry to hear about your S65 main bearings failing. Just out of interest, what does it sound like when the S65 main bearings are failing? I'm thinking it's a different noise to rod bearing knock? Or is it?
.

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From my research, there appears to be an anti siphon flap so i do not think that will work. Someone correct me if i am wrong. I would only try octane booster as a last resort. I also tried Ista +, no go. It can read from the fuel pump module, but it has no way to activate it. From what i read on these forums, the best idea I've found is to remove the fuel pump and use a drill pump to pump out the tank. My worry is, i guarantee i am gunna spill some and its going to go all over the inside my the car.

[DrFerry]

Originally Posted by bmwm3s65

From my research, there appears to be an anti siphon flap so i do not think that will work. Someone correct me if i am wrong. I would only try octane booster as a last resort. I also tried Ista +, no go. It can read from the fuel pump module, but it has no way to activate it. From what i read on these forums, the best idea I've found is to remove the fuel pump and use a drill pump to pump out the tank. My worry is, i guarantee i am gunna spill some and its going to go all over the inside my the car.

Just out of interest, what does it sound like when the S65 main bearings are failing? I'm thinking it's a different noise to rod bearing knock? Or is it?

[MaximusB]

I’ve done it on a previous car, not on the m3. But you can’t siphon from the gas filler. The tank has baffles to prevent gas from sloshing around. I took out the fuel pump and siphon from there, as that will get you to the lowest point of the tank and baffles are designed to drain/let gas get to the pump quickly, if that makes sense.

[amrazM]

ista lets you run the fuel pump or you could put power on it but youll need a way to to connect to the front fuel line with the right type of connection.

[tbuck]

Ok, sorry, but this is a whole lot about nothing. 1 can of octane booster generally will bring the whole tank up several points. So long as it is within 91 and 93 it will be fine with no issues. Read the can and add as much as needed. OP, no need to over thinking this rather simple issue.

[amg6975]

Just drive moderately for this tank. Don't go crazy with the RPM or throttle and it will be 100% fine. Get to half a tank and fill back up with 93 and let it eat.

Higher octane just resists detonation which will not be a problem if you're not flogging it.

[bmwm3s65]

Originally Posted by amg6975

Just drive moderately for this tank. Don't go crazy with the RPM or throttle and it will be 100% fine. Get to half a tank and fill back up with 93 and let it eat.

Higher octane just resists detonation which will not be a problem if you're not flogging it.

That is exactly what i did and how i realized i put the wrong octane in. I gunned the throttle a few times and heard it knock only at take off. I got scared drove easy the rest of the way home so i could figure out how to pump the gas out. i am not losing a second engine because i messed up. I ordered the parts to pump out the tanks from the fuel pump and transfer pump. I'll do one side at a time, then fill it with a gallon or 2 of 93 and go to the gas station and gas it up the right way. Done.

[bmwm3s65]

Originally Posted by amrazM

ista lets you run the fuel pump or you could put power on it but youll need a way to to connect to the front fuel line with the right type of connection.

If you could provide instructions on how to do this on a 2009 lci m3 i would really appreciate it. I've spent hours looking through ista, inpa and protool and i cannot find it. I confirmed that component triggering does not have the ability to do that and i cannot find it under service functions in ista either.

[MechEngineer408]

3 bottles of octane booster and call it a day

[bmwm3s65]

finally got my car running again. I ended up pumping out the tank and refilling with the proper octane because i could not find any way to activate the fuel pump via software. I tried ista, protool and inpa. if someone knows for certain that it works through software, let me know. Some lessons learned. I would strongly recommend not using a drill pump unless you can find one designed to pump gasoline and has a ground wire. At first i tried a drill pump and the gas vapors started smoking. I ended up buying an electric pump made to pump gasoline and it had a ground wire. I believe the ground wire is there because as fuel moves through the tubes, it creates static electricity and the ground wire helps prevent that from building up. Also, i recommend getting the fuel pump lock ring removal tool to remove the fuel pump, much, much easier at least for me. I am getting ready to replace the fuel pump and sender soon so i can use the tool again for that job as well.