Do I need to reset ECU after spark plug change?

tm6030 · 04-16-2014, 03:13 PM

Hey,

I recently got a check engine sign which was due to misfire. I changed all my spark plugs with the Bosch ones and one bad coil. Car is smooth and does not give any more symptoms of a misfire. But only while idling in park, i feel a slight hiccup once in a while. I was reading around that you need a BT tool to reset the misfire code (no check engine sign), or I can unplug my battery for an hour or so to reset the ecu to get use to the new sparks. Or will the ecu adapt by itself ?

Thank you,
Teddy

Blackhawk36 · 04-16-2014, 04:26 PM

No reset. You can reset adaptions but that isn't necessary. It will adapt on its own. The slightly rough idle can be carboned up intake ports if you have more than 80k KM and haven't had the walnut blast done.

tm6030 · 04-16-2014, 04:27 PM

Quote:

Originally Posted by Blackhawk36

No reset. You can reset adaptions but that isn't necessary. It will adapt on its own. The slightly rough idle can be carboned up intake ports if you have more than 80k KM and haven't had the walnut blast done.

I have 41,000kms it a 09

e92_enthusiast_1 · 04-16-2014, 04:31 PM

Can you explain the "hiccup"? What are the symptoms? Like the revs go up and down on it's own in idle? Might not be that serious. Worst case, its carbon.

tm6030 · 04-16-2014, 04:35 PM

Quote:

Originally Posted by e92_enthusiast_1

Can you explain the "hiccup"? What are the symptoms? Like the revs go up and down on it's own in idle? Might not be that serious. Worst case, its carbon.

No the rmp does not move, while idle you feel a slight hicup once in a while.

Osirisman · 04-16-2014, 05:43 PM

I doubt it's carbon build up with mileage being that low.
It runs fine under wot?

tm6030 · 04-16-2014, 06:59 PM

Quote:

Originally Posted by Osirisman

I doubt it's carbon build up with mileage being that low.
It runs fine under wot?

Wot? But as in stepping on the pedal its amazing.

Andrewah05 · 04-16-2014, 07:04 PM

Hiccups seem to be carbon, use to have them on mine until the carbon cleaning, are all your plugs torqued to spec etc?

tm6030 · 04-16-2014, 07:06 PM

Quote:

Originally Posted by Andrewah05

Hiccups seem to be carbon, use to have them on mine until the carbon cleaning, are all your plugs torqued to spec etc?

No hand tightened ... Not to much not to loose... Please don't tell me this is a concern UGH

Andrewah05 · 04-16-2014, 07:09 PM

Its a possibility, Osirisman is right, shouldn't have rough idling or hiccups at such low mileage due to carbon. I remember I had slight hiccups when wot (wide open throttle) turned out to be a loose injectors.

tm6030 · 04-16-2014, 07:11 PM

Quote:

Originally Posted by Andrewah05

Its a possibility, Osirisman is right, shouldn't have rough idling or hiccups at such low mileage due to carbon. I remember I had slight hiccups when wot (wide open throttle) turned out to be a loose injectors.

Its not rough idle, it settle bellow 600 rpm and does not move. I just feel a slight hiccup like every 5-6 mins in idle only when in park, not drive.

Andrewah05 · 04-16-2014, 07:15 PM

Rough idle doesn't necessarily mean the idles bounce around, but you feel the rough shaking or as you describe hiccups, and can't really say what it is but that sounds carbon related, hope you figure out soon, check the plugs as well if you want too.

tm6030 · 04-16-2014, 07:17 PM

Quote:

Originally Posted by Andrewah05

Rough idle doesn't necessarily mean the idles bounce around, but you feel the rough shaking or as you describe hiccups, and can't really say what it is but that sounds carbon related, hope you figure out soon, check the plugs as well if you want too.

Its not rough shaking, its like a hiccup.. Its there for 1-2 seconds max and disappears.. Can this be because my car is getting used to the new sparks and the new coil?

NICKBRUM · 04-16-2014, 08:26 PM

Quote:

Originally Posted by teddymultani

Hey,

I recently got a check engine sign which was due to misfire. I changed all my spark plugs with the Bosch ones and one bad coil. Car is smooth and does not give any more symptoms of a misfire. But only while idling in park, i feel a slight hiccup once in a while. I was reading around that you need a BT tool to reset the misfire code (no check engine sign), or I can unplug my battery for an hour or so to reset the ecu to get use to the new sparks. Or will the ecu adapt by itself ?

Thank you,
Teddy

Did you go with with OEM plugs?? I tried Bosch im my M3 and it did the same little blurp on idle. I said screw it and ate the cost and got OEM ngk's problem solved lesson learned.

tm6030 · 04-16-2014, 09:07 PM

Quote:

Originally Posted by NICKBRUM

Did you go with with OEM plugs?? I tried Bosch im my M3 and it did the same little blurp on idle. I said screw it and ate the cost and got OEM ngk's problem solved lesson learned.

Yes oem.. Not from bmw though ..

NICKBRUM · 04-16-2014, 09:29 PM

Quote:

Originally Posted by teddymultani

Yes oem.. Not from bmw though ..

Vendor doesn't matter just MFG. Im not familiar with the N54 so hopefully someone else has a good idea.

04-16-2014, 03:13 PM	#1
tm6030 Lieutenant 54 Rep 504 Posts Drives: Bmw 335i 2009 Join Date: Sep 2013 Location: toronto iTrader: (0)	Do I need to reset ECU after spark plug change? Hey, I recently got a check engine sign which was due to misfire. I changed all my spark plugs with the Bosch ones and one bad coil. Car is smooth and does not give any more symptoms of a misfire. But only while idling in park, i feel a slight hiccup once in a while. I was reading around that you need a BT tool to reset the misfire code (no check engine sign), or I can unplug my battery for an hour or so to reset the ecu to get use to the new sparks. Or will the ecu adapt by itself ? Thank you, Teddy
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04-16-2014, 04:26 PM	#2
Blackhawk36 Captain 30 Rep 644 Posts Drives: 2007 335i 6MT No iDrive Join Date: May 2009 Location: MD iTrader: (0)	No reset. You can reset adaptions but that isn't necessary. It will adapt on its own. The slightly rough idle can be carboned up intake ports if you have more than 80k KM and haven't had the walnut blast done.
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04-16-2014, 04:31 PM	#4
e92_enthusiast_1 Lieutenant Colonel 35 Rep 1,652 Posts Drives: '10 AW/CR e92 6mt 335i Join Date: Mar 2012 Location: Chandler, AZ iTrader: (1) Garage List 2010 BMW 335i [0.00]	Can you explain the "hiccup"? What are the symptoms? Like the revs go up and down on it's own in idle? Might not be that serious. Worst case, its carbon. __________________ COBB AP Stg 2+ FMIC Aggressive \| VRSF 3" Catless DP \| COBB FMIC \| BMS DCI \| CP-e Metal Charge Pipe \| 370+ whp/435+ lb.ft torque
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04-16-2014, 05:43 PM	#6
Osirisman First Lieutenant 389 Rep 388 Posts Drives: 2011 335is, 2017 m2, 2019 m550 Join Date: Feb 2014 Location: Cape Coral, FL iTrader: (0)	I doubt it's carbon build up with mileage being that low. It runs fine under wot?
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04-16-2014, 07:04 PM	#8
Andrewah05 Captain 70 Rep 628 Posts Drives: 335i TiAg Join Date: Sep 2012 Location: Toronto, Canada iTrader: (0)	Hiccups seem to be carbon, use to have them on mine until the carbon cleaning, are all your plugs torqued to spec etc?
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04-16-2014, 07:09 PM	#10
Andrewah05 Captain 70 Rep 628 Posts Drives: 335i TiAg Join Date: Sep 2012 Location: Toronto, Canada iTrader: (0)	Its a possibility, Osirisman is right, shouldn't have rough idling or hiccups at such low mileage due to carbon. I remember I had slight hiccups when wot (wide open throttle) turned out to be a loose injectors.
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04-16-2014, 07:15 PM	#12
Andrewah05 Captain 70 Rep 628 Posts Drives: 335i TiAg Join Date: Sep 2012 Location: Toronto, Canada iTrader: (0)	Rough idle doesn't necessarily mean the idles bounce around, but you feel the rough shaking or as you describe hiccups, and can't really say what it is but that sounds carbon related, hope you figure out soon, check the plugs as well if you want too.
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