Put 110 octane race fuel in my M, started misfiring BADLY!!

[chris604]

I had some race fuel in my race car, and was going to put in fresh fuel for this season. So, I drained it, and just tried it in my X5M. Ran very well for the first 1/2 hour or so. Seemed like more power, than just 91 octane fuel. After the tank was almost empty, started misfiring like CRAZY!!! Just misfire on cylinder 6 only. Kept doing it over and over, and got the reduced power, warning, etc. etc. The thing then didn't go over 30 km/h , LOL. Filled it with 91 octane, did the same thing for a few miles, now drives fine. Bottom line: Don't put race fuel in your street car! hahah.

But also making some weird weird noses, when I shut it off. Will post some vids of it soon. And, the water pump or something was making some awful gurgling noises, I've never heard that before as well.

[chris604]

[chris604]

[chris604]

[Sophisticated Redneck]

Originally Posted by chris604

I had some race fuel in my race car, and was going to put in fresh fuel for this season. So, I drained it, and just tried it in my X5M. Ran very well for the first 1/2 hour or so. Seemed like more power, than just 91 octane fuel. After the tank was almost empty, started misfiring like CRAZY!!! Just misfire on cylinder 6 only. Kept doing it over and over, and got the reduced power, warning, etc. etc. The thing then didn't go over 30 km/h , LOL. Filled it with 91 octane, did the same thing for a few miles, now drives fine. Bottom line: Don't put race fuel in your street car! hahah.

But also making some weird weird noses, when I shut it off. Will post some vids of it soon. And, the water pump or something was making some awful gurgling noises, I've never heard that before as well.

What brand of 110 did you use?

That noise sounds like your turbo water pump, there is a recall on them, check your VIN against the BMW recall to see if it has been replaced yet. It can also make that noise if it gets air in the system, check your coolant lines to the turbos for leaks and your coolant level.

[chris604]

Originally Posted by Sophisticated Redneck

What brand of 110 did you use?

That noise sounds like your turbo water pump, there is a recall on them, check your VIN against the BMW recall to see if it has been replaced yet. It can also make that noise if it gets air in the system, check your coolant lines to the turbos for leaks and your coolant level.

Ok, cool. I used Sunoco. I was assuming theyre all the same. Not cheap stuff tho. Where can I see the recall listings?

Thanks

[chris604]

Originally Posted by Sophisticated Redneck

What brand of 110 did you use?

That noise sounds like your turbo water pump, there is a recall on them, check your VIN against the BMW recall to see if it has been replaced yet. It can also make that noise if it gets air in the system, check your coolant lines to the turbos for leaks and your coolant level.

Found this info: https://www.cars.com/research/bmw-x5...alls/?zc=98230

Do you think calling the dealer will get them to replace it?

[Thecastle]

It looks like your problems maybe just incidental. One problem besides the water pump, is looks likely you used leaded fuel. Most sunoco 110+ octane, is leaded. Running leaded in an unleaded car is bad if you still have your catalytic converters. Lead clogs the cats, and can coat plugs and etc.

Stick with 100-107 octane. Don't use AV gas, as its leaded often times as well.

On that note I've run 100+ octane fuels with no issues. As long as they were not leaded. https://petroleumservicecompany.com/...5-gallon-pail/

[chris604]

Originally Posted by Thecastle

It looks like your problems maybe just incidental. One problem besides the water pump, is looks likely you used leaded fuel. Most sunoco 110+ octane, is leaded. Running leaded in an unleaded car is bad if you still have your catalytic converters. Lead clogs the cats, and can coat plugs and etc.

Stick with 100-107 octane. Don't use AV gas, as its leaded often times as well.

On that note I've run 100+ octane fuels with no issues. As long as they were not leaded. https://petroleumservicecompany.com/...5-gallon-pail/

Oh oh. Seems OK now tho. Still got the extended warranty on it just in case. But, I definitely did notice a power difference. I ran it as hard as I could, and no misfire. I'm kind of used to the random noises in it now tho. Something's bound to die on it soon, LOL. Also, the thing is just gulping oil, and has been getting much worse recently. Is there a safety check on the computer, that won't let you start the car if the oil is too low? I saw a message on the screen saying something like 'Oil level sufficient to start the car, but level won't be determined until after driving the vehicle'. But, will it just refuse to start if it's below a certain point? I just filled it up with 2L of oil, and it's in the red again, after a week.

[chris604]

Originally Posted by Sophisticated Redneck

What brand of 110 did you use?

That noise sounds like your turbo water pump, there is a recall on them, check your VIN against the BMW recall to see if it has been replaced yet. It can also make that noise if it gets air in the system, check your coolant lines to the turbos for leaks and your coolant level.

Turbo pump seems good, had it changed about two years ago, the fluid and hoses, I mean.

[Thecastle]

If your burning that much oil your misfires are probably from having clogged cats. The leaded gas didn’t help the cats. You need to find the source of your oil consumption, before replacing the cats (temp fix would be to remove them)

Typically oil loss sources are
Big leak
Bad valve stem seals
Bad ccv system
Bad turbos
Bad cylinders aka scored bores from carbon build up or broken piston rings.
Blown head gasket (not common)

p.s. we had a ford years ago that was a 2-stroke lol (they all start as 4 strokes). It burned a quart of oil every 10 gallons of gas. The cat totally plugged so we had to gut it to get it to run right. That was a fine car, the only difference between 1/4 throttle and full throttle was the amount of smoke...

[MarcusNergaard]

Is there any way to program the car to run race fuel?

[Thecastle]

Sure, a tune.

Lots of people tune for e85 here because it has much higher octane and is low cost in the us.

What I read suggest the x5m standard mapping adapts well even to 100 octane.