[MakaniX3]

I am at a loss. I recently purchased a 2011 BMW X3 (f25) and it has begun to have a seemingly undiagnosable problem.

This problem used to happen around 60 mph where there was a slight shake and the engine would all but loose all acceleration.When I pressed the gas it would rev up into 4000 rpm or higher and refuse to accelerate. This in turn would make the shaking worse and the engine sounded like it was humming and would get worse until I pulled to the side of the road.

The transmission fluid was changed twice (first shop put the wrong kind in, the second time it was changed by a bmw dealership).

Now after the the transmission fluid change the problem has started to happen at 40 mph as the title states. It does not happen during every drive and there is no error code that I can see associated with the transmission. It happened twice in one day this week and I pressed the break pedal firmly and gave it some gas and it seemed to fix the problem but has made the car unreliable and very confusing.

Here are the only error codes it is showing:

1C0102: Engine-oil pressure control, static: engine-oil pressure too low
4809AB: DSC: Undervoltage in vehicle
801A4A: Deactivation IRS and tilt sensor by customer function (I'm also trying to fix this)

The check engine light and oil sensor light have not come on.

Any help would be appreciated because I am stumped. Also please explain like I'm 5 as I am still learning terminology. Thanks

[mwat]

You don't want to mess around with low oil pressure, best case maybe it's a sensor.
I would tow it somewhere ASAP.

How many miles have you driven since this popped up?

Could also be something as silly as a battery that's on it's last leg. When's the last time you changed your battery?

[MakaniX3]

I don't plan to mess with the oil pressure and I've never charged the battery, though every shop I've been to says it's fine.

I think it is actually misfiring while I'm driving - I thought it was just loud popping noises and did not consider loss of power and shaking in that category until I looked it up. My guess at this point is spark plug as its 56,600 miles - some sources say to replace them every 30,000 - 60,000 miles.

[mwat]

Originally Posted by MakaniX3

I don't plan to mess with the oil pressure and I've never charged the battery, though every shop I've been to says it's fine.

I think it is actually misfiring while I'm driving - I thought it was just loud popping noises and did not consider loss of power and shaking in that category until I looked it up. My guess at this point is spark plug as its 56,600 miles - some sources say to replace them every 30,000 - 60,000 miles.

If the battery is the original from factory I would absolutely look into getting that changed. I DIY'd my sparkplugs and coilpacks at 55k miles and I had no misfires etc at that point. Could be sparkplugs, but in my opinion you would be getting misfire codes if that was the case.

FYI not sure where you have brought it but I'm told by BMW techs that if any undervolt codes exist they change the battery as step 1.

But seriously, I wouldn't drive it until you figure out the oil pressure issue.