Loss of power under harsh acceleration

karlAtkins · 02-25-2024, 03:35 AM

On my 2012 40d Whilst driving today under harsh acceleration (foot to floor) in sport mode the car seemed to pull ok until it got to 110mph (I will just say this was on private land) and then seemed to hit a brick wall as if there was a limiter No warning lights or messages. But when under light acceleration would pull to 100mph with no problems. I’ve had a look through various forums and nothing identical my issue but similar ones with varying possibilities as to what might be causing it range from vacuum hoses, injector issues, coil packs, turbo and high pressure fuel pump. But with no end results. Has anyone else had this issue and if so what was the outcome?
Many thanks
Karl

wcs531 · 02-25-2024, 06:34 AM

I suspect that there will be shadow/pending codes stored in the ECU even though you don't have a check engine light illuminated.

We didnt get the N57 engine in the E70 here in the states so your car will be more similar to the F15 X5 when it comes to powertrain issues, you may get more helpful advice over there (with or without shadow codes if they do exist).

DialedIn · 02-25-2024, 06:58 AM

You probably want to put a gauge to your fuel line and see if you got the proper and consistent fuel pressure.

Under wide open throttle if you don't have enough flow the pressure can drop.

If you don't know when the fuel filter was changed last it would be a good idea to put a new filter on.

02-25-2024, 03:35 AM	#1
karlAtkins Registered 0 Rep 1 Posts Drives: E70 40d Join Date: Feb 2024 Location: UK iTrader: (0)	Loss of power under harsh acceleration On my 2012 40d Whilst driving today under harsh acceleration (foot to floor) in sport mode the car seemed to pull ok until it got to 110mph (I will just say this was on private land) and then seemed to hit a brick wall as if there was a limiter No warning lights or messages. But when under light acceleration would pull to 100mph with no problems. I’ve had a look through various forums and nothing identical my issue but similar ones with varying possibilities as to what might be causing it range from vacuum hoses, injector issues, coil packs, turbo and high pressure fuel pump. But with no end results. Has anyone else had this issue and if so what was the outcome? Many thanks Karl
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02-25-2024, 06:34 AM	#2
wcs531 Second Lieutenant 97 Rep 281 Posts Drives: E90 335xi / E70 X5d Join Date: Jul 2014 Location: Philadelphia iTrader: (1)	I suspect that there will be shadow/pending codes stored in the ECU even though you don't have a check engine light illuminated. We didnt get the N57 engine in the E70 here in the states so your car will be more similar to the F15 X5 when it comes to powertrain issues, you may get more helpful advice over there (with or without shadow codes if they do exist).
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02-25-2024, 06:58 AM	#3
DialedIn Private First Class 119 Rep 157 Posts Drives: E70 & E92 Join Date: Aug 2018 Location: Scandinavia iTrader: (0)	You probably want to put a gauge to your fuel line and see if you got the proper and consistent fuel pressure. Under wide open throttle if you don't have enough flow the pressure can drop. If you don't know when the fuel filter was changed last it would be a good idea to put a new filter on.
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