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knock sensor fault code / poor acceleration

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Pickster
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Joined: Fri Jul 19, 2019 8:30 am
Location: West Yorkshire

knock sensor fault code / poor acceleration

Post by Pickster » Tue Aug 06, 2019 9:40 am

Hi all,
I'm new to the forum but have recently encountered an issue that someone maybe able to assist with.

2011 E89 23i Msport.

Recently purchased been running well and have been enjoying the car.
changed fuel from standard shell to V power ( nor sure what the previous owner was running on).

Took the car on a run to Scotland over the weekend from Leeds , firs leg obviously all motorway driving A1, A66 M6 etc. car was running great. came off the motorway outside Glasgow and car developed a hesitation when accelerating. Parked the car up at the hotel for an hour then took it out to test it. car ran fine sigh of relief. Next morning headed out to Loch Lomond bit of motorway driving then onto the A82 same issue hesitation on acceleration, also noticed oil temp was lower than normal and took a lot longer to warm up.
now in the middle of nowhere parked car up for half an hour or so and set off again to next hotel on Loch Fyn. Car ran fine, Oil temp rose to where it would normally be. Car ran fine rest of day. next morning headed south car ran fine. Ran fine all the way to next stop over and then again the next day back to Leeds.

Got back home and pal put a diagnostic reader on the car. Only fault that came up was Knock sensor fault code 2.

Any Thoughts ?

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Smartbear
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Location: a barn in Somerset

knock sensor fault code / poor acceleration

Post by Smartbear » Tue Aug 06, 2019 9:44 am

Pickster wrote: Tue Aug 06, 2019 9:40 am Hi all,
I'm new to the forum but have recently encountered an issue that someone maybe able to assist with.

2011 E89 23i Msport.

Recently purchased been running well and have been enjoying the car.
changed fuel from standard shell to V power ( nor sure what the previous owner was running on).

Took the car on a run to Scotland over the weekend from Leeds , firs leg obviously all motorway driving A1, A66 M6 etc. car was running great. came off the motorway outside Glasgow and car developed a hesitation when accelerating. Parked the car up at the hotel for an hour then took it out to test it. car ran fine sigh of relief. Next morning headed out to Loch Lomond bit of motorway driving then onto the A82 same issue hesitation on acceleration, also noticed oil temp was lower than normal and took a lot longer to warm up.
now in the middle of nowhere parked car up for half an hour or so and set off again to next hotel on Loch Fyn. Car ran fine, Oil temp rose to where it would normally be. Car ran fine rest of day. next morning headed south car ran fine. Ran fine all the way to next stop over and then again the next day back to Leeds.

Got back home and pal put a diagnostic reader on the car. Only fault that came up was Knock sensor fault code 2.

Any Thoughts ?
Hi, I’d probably change the knock sensor-a faulty one would probably take the edge off the engine performance.
Rob
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e89 Sdrive 20i, plenty of mumbo & good economy-the thinking bears z4
e89 Sdrive 30i, this ones busted, pass me another...
e85 3.0si sold

Pickster
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Posts: 205
Joined: Fri Jul 19, 2019 8:30 am
Location: West Yorkshire

knock sensor fault code / poor acceleration

Post by Pickster » Tue Aug 06, 2019 9:54 am

Thanks for the reply Rob,

Do you think the change in fuel type was just a coincidence ?

mcbutler
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Location: Plymouth

knock sensor fault code / poor acceleration

Post by mcbutler » Sat Aug 10, 2019 1:06 pm

If you have a faulty knock sensor the ECU will either retard the ignition (reducing performance) if it is sensing 'false knocks'. Or if it not sensing any knocking it will advance the ignition (increasing performance), as happens when VPower is used as it resists knocking.
However the ECU usually takes a tank full or two of pure Vpower to sort itself out.
If the ECU senses the knock sensor as 'missing' broken wire or similar it will default to a set value.

Unlikely that the fuel change is causing this, just get the sensor changed (I think there are two but not sure).
Mark
Plymouth
E89
35i
Carmine Red
Black leather

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