[LastBastion1005]

I was not paying attention and accidentally filled up my F87 with 87 fuel. Should I siphon it out, or will I be fine with just one tank?

[PHX102]

Originally Posted by LastBastion1005

I was not paying attention and accidentally filled up my F87 with 87 fuel. Should I siphon it out, or will I be fine with just one tank?

Personally I would just take it easy driving out half a tank or so, and top off with the good stuff.


Edit: Even better if you have access to high octane race gas…couple gallons will get you back to premium levels.

[OGM2]

I just did the exact same thing. This car does not like 87 that’s for sure. I just left it in and topped it off when it got down to 3/4. I’ve done this twice now and still had a 1/4 when I had the brain fart so I will top it off once more at 3/4 before running it down. It’s already not noticeable but prior to the first top off it was noticeably coarse and less power/responsiveness.

[F87source]

The cars smart enough to adapt by pulling timing, but you must baby it like crazy to ensure no major knock events damage the engine. Also make sure you don't have low rpm, high gear, high load events because LSPI with low octane fuels would be devestating.


A can of octane booster would help if you had some available locally, just make sure the octane booster is good and not a bad brand.

[Tag]

If you have a full tank just pour in some octane booster and go easy on it. Top it off as soon as your burn off a couple of gallons with high octane gas and you'll be fine.

[///M TOWN]

😳

I'd siphon that gas into somebody else's car

And then I would follow up with some BMW fuel system cleaner prior to properly filling up again

[F87source]

Originally Posted by ///M TOWN

😳

I'd siphon that gas into somebody else's car

And then I would follow up with some BMW fuel system cleaner prior to properly filling up again

You can't siphon these cars anymore, bmw put something in the fuel filler neck that prevents tubes from going down into the tank.

[///M TOWN]

Originally Posted by F87source

You can't siphon these cars anymore, bmw put something in the fuel filler neck that prevents tubes from going down into the tank.

Good to know dude

Can you drain the tanks content from below ⁉️

[F87source]

Originally Posted by ///M TOWN

Good to know dude

Can you drain the tanks content from below ⁉️

No I do not believe there is a hole to drain from below either. So if you are really in a pinch to drain the tank these are the options:

1. Take off the lpfp hat and you have access directly into the tank from inside of the car.

2. Disconnect the lpfp line and turn the car on into accessory mode and let the lpfp pressurize itself and that will cause fuel to drain. I am not sure if the pump cuts off eventually so you might have to cycle the ignition alot.

3. if you have an inline fuel filter like the one bend calibration sells there is a bung on it that allows you to depressurize the fuel line and that will allow you to empty the tank like method 2 but you don't have to disconnect anything.

[KevinC]

Just take it easy on this tank, and/or add some octane booster if you're really paranoid. Complete waste of time/money to drain the 87. IMHO.

[Anonymoose]

Take it easy like others have said. If you're really concerned baby it till you're down about 4 gallons and find 100 octane to replace it with.

[///M TOWN]

Originally Posted by KevinC

Just take it easy on this tank, and/or add some octane booster if you're really paranoid. Complete waste of time/money to drain the 87. IMHO.

Oh absolutely not if it's not easily done I'm clearly it's not

But I'd definitely stick a small bottle of BMW fuel system cleaner in before I refill the tank just to make myself feel better

[(K)]

Run it to near empty, pop a bottle of octane booster, fill up with premium, and you'll be fine. Do this for the next 2 or so fills if you're still concerned.

These tanks are small so you'll be back to the gas station before the end of the week.

[Zeese]

Not to worry. Don't flog the beast (the car) and, as mentioned previously, the gas tank is so darn small that topping off with "Supreme" and you will be fine in no time all. So will the engine.

For sh*ts and giggles:
87 octane on bimmerpost.com

Click and Clack

[Poochie]

Originally Posted by F87source

You can't siphon these cars anymore, bmw put something in the fuel filler neck that prevents tubes from going down into the tank.

Damn, when I was a like 8 years old and poor, my dad use to have me siphon gas from his company vehicle (free gas), to throw into the family car.. All you needed was a hose, a lung and some mint. 😁

It sucks BMW took that away from future generations.. 😂

[F87source]

Originally Posted by Poochie

Damn, when I was a like 8 years old and poor, my dad use to have me siphon gas from his company vehicle (free gas), to throw into the family car.. All you needed was a hose, a lung and some mint. ��

It sucks BMW took that away from future generations.. ��

Yeah it really does suck, I want to siphon out the old gas after winter storage and put it into my daily. But nope bmw blocked off the fuel filler. I actually think it might be some government regulation though, but I am not sure.

The other methods to access the fuel tank (remove lpfp) while the tank is full is pretty dangerous so yeah no real means to empty the tank except driving it. So I use some good fuel stabilizer to help mitigate the effects of winter storage on the fuel.

[Poochie]

Originally Posted by F87source

Yeah it really does suck, I want to siphon out the old gas after winter storage and put it into my daily. But nope bmw blocked off the fuel filler. I actually think it might be some government regulation though, but I am not sure.

The other methods to access the fuel tank (remove lpfp) while the tank is full is pretty dangerous so yeah no real means to empty the tank except driving it. So I use some good fuel stabilizer to help mitigate the effects of winter storage on the fuel.

Thanks for the info, always informative!

Unrelated question, can you still "push/kick start" a modern manual BMW? Where when the battery or starter is dead, you can still power up the engine, by letting the car roll, shift into second gear and pop the clutch - thus, starting the vehicle without using the ignition..

https://en.wikipedia.org/wiki/Push_start

[F87source]

Originally Posted by Poochie

Thanks for the info, always informative!

Unrelated question, can you still "push/kick start" a modern manual BMW? Where when the battery or starter is dead, you can still power up the engine, by letting the car roll, shift into second gear and pop the clutch - thus, starting the vehicle without using the ignition..

https://en.wikipedia.org/wiki/Push_start

I have no idea tbh, but I don't know if BMW's ignition system works that way since it's a push button start that relies on a clutch position sensor. So there's no ignition switch that is in the "engine start mode" like the civic had in that video.

So what I think would happen on a BMW is that you'll have it in accessory mode because you can't start It and a failed start would resort back to accessory mode not that start position the Honda was in (this is the part it should hinge on), you'll roll it in a gear then when you let out the clutch the car will slow down and stop. It will not start because you were in accessory mode to begin with and you have to click the button again to start, but you can do that with the clutch pedal pulled out a bit. So I don't think it will work on a BMW, but I've yet to try and probably will never try, as if the battery is dead I have equipment to jump start it and get it in my garage while I prepare to install a new battery.

[Laguna Seca Blue]

Originally Posted by F87source

I have no idea tbh, but I don't know if BMW's ignition system works that way since it's a push button start that relies on a clutch position sensor. So there's no ignition switch that is in the "engine start mode" like the civic had in that video.

So what I think would happen on a BMW is that you'll have it in accessory mode because you can't start It and a failed start would resort back to accessory mode not that start position the Honda was in (this is the part it should hinge on), you'll roll it in a gear then when you let out the clutch the car will slow down and stop. It will not start because you were in accessory mode to begin with and you have to click the button again to start, but you can do that with the clutch pedal pulled out a bit. So I don't think it will work on a BMW, but I've yet to try and probably will never try, as if the battery is dead I have equipment to jump start it and get it in my garage while I prepare to install a new battery.

Unless something has changed dramatically since the E9x generation, you can indeed pop the clutch while in gear on a rolling bmw to get it it running. With your foot off the clutch, pressing the start button twice will put it in ignition on mode. Pressing the clutch in after this will not put it back into ACC mode. Same as an automatic (but with brake instead of clutch).

[F87source]

Originally Posted by Laguna Seca Blue

Unless something has changed dramatically since the E9x generation, you can indeed pop the clutch while in gear on a rolling bmw to get it it running. With your foot off the clutch, pressing the start button twice will put it in ignition on mode. Pressing the clutch in after this will not put it back into ACC mode. Same as an automatic (but with brake instead of clutch).

Wait so with my foot off the clutch press the start button twice? Everytime I do that it just turns the car on and immediately shuts it right off. Is that because the e9x cars had a key slot?

[Fred Conoway]

Originally Posted by Poochie

Thanks for the info, always informative!

Unrelated question, can you still "push/kick start" a modern manual BMW? Where when the battery or starter is dead, you can still power up the engine, by letting the car roll, shift into second gear and pop the clutch - thus, starting the vehicle without using the ignition..

https://en.wikipedia.org/wiki/Push_start

Surprisingly, it is possible; BMW even lists the procedure in the owner's manual under "tow-starting":

[F87source]

Originally Posted by Fred Conoway

Surprisingly, it is possible; BMW even lists the procedure in the owner's manual under "tow-starting":

I guess it is possible lol! That is good to know.