Automotive Industry & PricingNewsCommunity Starter

2018 BMW 340i — would a large MSRP cut make you wait before buying?

PistonHunterCommunity StarterJul 15, 20262018 BMW 340i xDriveNYC
2018 BMW 340i xDrive, about 78,000 miles. Price cuts and incentives are good for new buyers but can hit recent owners resale hard. How much do you consider potential manufacturer price moves when buying a newer EV or luxury car? I am in NYC.
permalink

23 replies

RustBeltLearnerCommunity StarterCommunity StarterJul 15, 2026permalink
I'd treat 12V warnings as a no-ignore. On the 2018 BMW 340i, I'd get the 12V/DC-DC side checked even if the traction pack looks fine. Then you'll know the next fork. On “would a large msrp cut make you,” that was the fork that mattered for me. This is from a 2018 BMW 340i in NYC with 78,000 miles. Post the numbers (or the code) and people can get more specific. Parking it somewhere I can hear it better next time.
RustBeltTraveler721Community StarterCommunity StarterJul 15, 2026permalink
Low-voltage gremlins will strand you even with a full pack. Try a second charger before blaming the 2018 BMW 340i — site sharing and pack temp change the curve a lot. Then you'll know the next fork. This is from a 2018 BMW 340i in NYC with 78,000 miles. Do that first. Next check is the cheap one I can do in a driveway.
ShiftShopper690Community StarterCommunity StarterJul 15, 2026permalink
I'd treat 12V warnings as a no-ignore. On the 2018 BMW 340i, I'd get the 12V/DC-DC side checked even if the traction pack looks fine. Then you'll know the next fork. On “would a large msrp cut make you,” that was the fork that mattered for me. Verbal 'we'll take care of it' is not a plan. Climate here is different, so treat that as a local data point. I'm keeping receipts and dates in one folder.
WrenchCollectorCommunity StarterCommunity StarterJul 15, 2026permalink
Low-voltage gremlins will strand you even with a full pack. Try a second charger before blaming the 2018 BMW 340i — site sharing and pack temp change the curve a lot. I'd do that before spending real money. No need to make it theatrical. I'll poke at it this weekend.
CleanMechanicish787Community StarterCommunity StarterJul 15, 2026permalink
Low-voltage gremlins will strand you even with a full pack. Try a second charger before blaming the 2018 BMW 340i — site sharing and pack temp change the curve a lot. I'd do that before spending real money. This is from a 2018 BMW 340i in NYC with 78,000 miles. Verbal 'we'll take care of it' is not a plan. Happens in gear, not in park, for what that's worth.
WrenchCollectorCommunity StarterCommunity StarterJul 15, 2026permalink
Don't clear the alert just to make the screen pretty. Leave the alerts on the 2018 BMW 340i so service can see what you saw. I'd do that before spending real money. This is from a 2018 BMW 340i in NYC with 78,000 miles. That's the sequence I'd use. Parking it somewhere I can hear it better next time.
PistonHunterCommunity StarterCommunity StarterJul 15, 2026permalink
It did would a large msrp cut make you twice this week, both times after sitting. No change in mileage feel. Happens in gear, not in park, for what that's worth.
WeekendNomadCommunity StarterCommunity StarterJul 16, 2026permalink
Charge curves lie if you don't match starting SOC and temp. Match starting SOC and battery temp if you're comparing 2018 BMW 340i charge sessions. I'd do that before spending real money. If you share a photo of the worksheet, easier to sanity-check. That's coming from doing this as an owner, not a shop. Wrote this up on my lunch break.
WrenchCollectorCommunity StarterCommunity StarterJul 17, 2026permalink
I hear you, though I'd still want a second check. On the 2018 BMW 340i, I'd get the 12V/DC-DC side checked even if the traction pack looks fine. I'd do that before spending real money. On “would a large msrp cut make you,” that was the fork that mattered for me. That's the sequence I'd use. Climate here is different, so treat that as a local data point. Doing the boring step first on purpose.
PistonHunterCommunity StarterCommunity StarterJul 16, 2026permalink
Cleared nothing. I want service to see the alert on the 2018 BMW 340i first. If that fails I'll eat the diagnostic fee.
PistonTuner368Community StarterCommunity StarterJul 16, 2026permalink
Charge curves lie if you don't match starting SOC and temp. Match starting SOC and battery temp if you're comparing 2018 BMW 340i charge sessions. That's where I'd start. Do that first. I'd rather pay for diagnosis than a second guess-repair.
ColdStartBuilder211Community StarterCommunity StarterJul 16, 2026permalink
I'd treat 12V warnings as a no-ignore. On the 2018 BMW 340i, I'd get the 12V/DC-DC side checked even if the traction pack looks fine. Then you'll know the next fork. On “would a large msrp cut make you,” that was the fork that mattered for me. That's the sequence I'd use. That's my plan before I call anyone.
PistonRoadie235Community StarterCommunity StarterJul 16, 2026permalink
Charge curves lie if you don't match starting SOC and temp. Match starting SOC and battery temp if you're comparing 2018 BMW 340i charge sessions. I'd do that before spending real money. This is from a 2018 BMW 340i in NYC with 78,000 miles. Run the total, not the monthly, before you commit. Parking it somewhere I can hear it better next time.
WeekendNomadCommunity StarterCommunity StarterJul 16, 2026permalink
I'd treat 12V warnings as a no-ignore. On the 2018 BMW 340i, I'd get the 12V/DC-DC side checked even if the traction pack looks fine. I'd do that before spending real money. On “would a large msrp cut make you,” that was the fork that mattered for me. Post the numbers (or the code) and people can get more specific. This is the filter I use when the thread starts repeating itself. I'm in no rush to be a hero on it.
ShiftShopper690Community StarterCommunity StarterJul 16, 2026permalink
Low-voltage gremlins will strand you even with a full pack. Try a second charger before blaming the 2018 BMW 340i — site sharing and pack temp change the curve a lot. I'd do that before spending real money. This is from a 2018 BMW 340i in NYC with 78,000 miles. If they can't show the line item, I assume it's hiding. I already checked the easy fluid levels.
TowTraveler350Community StarterCommunity StarterJul 16, 2026permalink
I'd treat 12V warnings as a no-ignore. On the 2018 BMW 340i, I'd get the 12V/DC-DC side checked even if the traction pack looks fine. That's where I'd start. On “would a large msrp cut make you,” that was the fork that mattered for me. That's the sequence I'd use. Climate here is different, so treat that as a local data point. If the story changes I'll post the new data.
WeekendNomadCommunity StarterCommunity StarterJul 16, 2026permalink
Low-voltage gremlins will strand you even with a full pack. Try a second charger before blaming the 2018 BMW 340i — site sharing and pack temp change the curve a lot. Then you'll know the next fork. Post the numbers (or the code) and people can get more specific. I'll update if anything new shows up.
PistonHunterCommunity StarterCommunity StarterJul 16, 2026permalink
Tried a second charger / second scan and the story on the 2018 BMW 340i didn't change. Parking it somewhere I can hear it better next time.
WeekendNomadCommunity StarterCommunity StarterJul 16, 2026permalink
Don't clear the alert just to make the screen pretty. Leave the alerts on the 2018 BMW 340i so service can see what you saw. Then you'll know the next fork. Happy to compare notes if your setup is different. That's my plan before I call anyone.
RoadTripSellerCommunity StarterCommunity StarterJul 16, 2026permalink
Don't clear the alert just to make the screen pretty. Leave the alerts on the 2018 BMW 340i so service can see what you saw. That's where I'd start. This is from a 2018 BMW 340i in NYC with 78,000 miles. Stop there until you know. I'm keeping receipts and dates in one folder.
WeekendNomadCommunity StarterCommunity StarterJul 17, 2026permalink
Quick add on that: On the 2018 BMW 340i, I'd get the 12V/DC-DC side checked even if the traction pack looks fine. That's where I'd start. On “would a large msrp cut make you,” that was the fork that mattered for me. Happy to compare notes if your setup is different. No warning lights, which is why I'm documenting it.
PistonTuner368Community StarterCommunity StarterJul 16, 2026permalink
Charge curves lie if you don't match starting SOC and temp. Match starting SOC and battery temp if you're comparing 2018 BMW 340i charge sessions. That's where I'd start. That's the whole play. I'm keeping receipts and dates in one folder.
ColdStartBuilder211Community StarterCommunity StarterJul 17, 2026permalink
Charge curves lie if you don't match starting SOC and temp. Match starting SOC and battery temp if you're comparing 2018 BMW 340i charge sessions. I'd do that before spending real money. No need to make it theatrical. That's coming from doing this as an owner, not a shop. Not driving it hard until I know more.
Sign in to reply

Similar discussions