Misfire and hard start

[Matthew Eckel]

Hi, I'm new to the forum. My son has a 2015 A3 2.0t premium plus. It has a random misfire under load. It's usually right after it shift into 2nd or 3rd around 2000rpm, give or take. It'll misfire a few times but go away if you continue to accelerate. I work on heavy trucks and have a heavy truck scanner. I was able to check codes with it and no active or inactive codes are set. When I look at the misfire parameters all four cylinders show 3 or 4 misfires on the last drive cycle. My son also said that intermittently he has a hard start condition (I have not experienced the hard start). It's very intermittent but seems like it only happens when the engine is warm. Has anyone had similar issues or any ideas what might be causing this?

Thanks!

Matt

[MikTip]

https://www.audizine.com/forum/showt...-unstable-idle

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https://www.audizine.com/forum/showt...rmittent-start

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https://www.audizine.com/forum/showt...-Hide-Cylinder

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https://www.audizine.com/forum/showt...-(P0300-P0304)

[MikTip]

Hi, I'm new to the forum. My son has a 2015 A3 2.0t premium plus. It has a random misfire under load. It's usually right after it shift into 2nd or 3rd around 2000rpm, give or take. It'll misfire a few times but go away if you continue to accelerate. I work on heavy trucks and have a heavy truck scanner. I was able to check codes with it and no active or inactive codes are set. When I look at the misfire parameters all four cylinders show 3 or 4 misfires on the last drive cycle. My son also said that intermittently he has a hard start condition (I have not experienced the hard start). It's very intermittent but seems like it only happens when the engine is warm. Has anyone had similar issues or any ideas what might be causing this?

Thanks!

Matt

Miles? The first thing people often do is change spark plugs and or coil packs...

[Matthew Eckel]

170,000 miles. Plugs and coils were changed about 6 months ago.

[Matthew Eckel]

https://www.audizine.com/forum/showt...-unstable-idle

- - - Updated - - -

https://www.audizine.com/forum/showt...rmittent-start

- - - Updated - - -

https://www.audizine.com/forum/showt...-Hide-Cylinder

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https://www.audizine.com/forum/showt...-(P0300-P0304)

Thanks for that MikTip. Very useful information!

[MikTip]

Has the engine been carbon cleaned?

[Matthew Eckel]

It has not. I'm debating whether to buy a fuel pump, an OBD11, or take it to a shop that I don't trust to have the carbon cleaning done.

[WtA4WtQ5]

I would do a compression check and look around with a bore scope before spending time or money on a carbon cleaning.