Engine running rough

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Bobeek
New
Posts: 7
Joined: Sun Feb 12, 2017 8:01 pm
Drives: MK7
Location: Bristol

Engine running rough

Post by Bobeek »

Hey guys,
So as it happened, the engine cut out one morning shortly after start, turns out no charge from alternator. After short inspection I quickly noticed that there is nothing plugged in to the 2 pin connector..I found the wires dangling under the alternator, without connector (!), only the pins insulation taped around separately.. long story short, ordered new connector, wires connected to alternator, tested and yess 14.5V on the battery.
Because I felt the engine running a bit rough I run a quick fault reading and it picked up a cylinder 1 misfiring. Cleared the fault, restarted the engine, the code never came back but it runs rough and it feels like 1 cylinder not running at all.
Where should I start? Logically thinking it’s something to do with the previous very low voltage?
Johntheo1
Bronze Member
Posts: 138
Joined: Mon Jan 11, 2021 8:52 am
Drives: 2018 MK10 AW1
Location: Cork

Re: Engine running rough

Post by Johntheo1 »

swap the coil with one of the others and see if the fault follows it.
RUM4MO
Bling Bling Diamond Member
Posts: 5859
Joined: Sat Dec 30, 2006 9:12 pm
Drives: B8 S4 & 6R/6C1 1.2TSI 110
Location: Mid Lothian

Re: Engine running rough

Post by RUM4MO »

Also make sure that the spark plugs are still okay as a duff plug can kill an old but still okay coil pack.

After getting caught out once, I made sure that I always had a spare coil pack (COP) in the car. One original make of factory fitted COPs seemed a lot worse than the other, Eldor was the brand that I preferred and especially ones NOT manufactured in Turkey!

Maybe check which brand(s) are currently fitted to this car, and their manufacturing date codes, and buy a reasonable branded new COP coil to help you out of this.

But do get all the spark plugs out and check them first to avoid damaging any or any more COP coils - doing that could save a lot of time and money.
Bobeek
New
Posts: 7
Joined: Sun Feb 12, 2017 8:01 pm
Drives: MK7
Location: Bristol

Re: Engine running rough

Post by Bobeek »

thanks I'll have a look tomorrow.. it just seems a bit suspicious that a spark plug and/or a ignition coil failed straight after that alternator issue. :roll:
CarbonChaos
Silver Member
Posts: 405
Joined: Mon Sep 03, 2018 9:43 pm
Drives: 2015 6C GTI DSG Oryx white 3 door.
Location: South west uk

Re: Engine running rough

Post by CarbonChaos »

Could you also clarify which engine we are talking about? ie is it a 3 cylinder?
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