Misfire on mk5 fsi

[Gticed]

I’ve been having misfires for the past month and I’ve replaced the coil pack and spark plugs and upgraded to the ngk plugs with r8 coils. When I did this the valve cover gasket was leaking because there was oil in all the coil pack and packed around the spark plugs I got a new gasket, cleaned it up, and replaced the sparks and coils. It continued to misfire I replaced the pcv valve that didn’t fix it. I’ve used fuel injector cleaner in my tank, still misfiring. My next guess is the fuel injectors I just don’t want to spend the money on them if it could be something else. I have a catless downpipe I don’t know if that’s contributing to it or not. I know this is a common problem but it seems like everyone’s is fixed by replacing the sparks and coils any help is greatly appreciated.

 

[ROH ECHT]

Are misfires confirmed in the data or has stored DTC? Or is it something you feel?
Are the coils genuine Audi R8 or Red Top R8 look alikes?
Are the plugs BKR7EIX?
Is there any oil or lube on the threads for the plugs in the head that is not Dielectric...affecting the ground?
Is your car tuned or have a bigger turbo?


I am guessing it didn't need the R8 coils. Those have a resistance of 5.31 M ohm. The OEM stock coils are 3.3 M ohm. Generally the R8 are used for higher boost when one suspects the arc is getting blown out....and they also gap the plugs to 0.024" to 0.026". OEM coils are meant to burn longer with a larger plug gap of 0.032 or 0.8mm. If Tuned, OEM coils may require a plug gap of 0.028" or 0.7mm. The NGK BKR7EIX are preset at 0.032".

 

[Gticed]

Are misfires confirmed in the data or has stored DTC? Or is it something you feel?
Are the coils genuine Audi R8 or Red Top R8 look alikes?
Are the plugs BKR7EIX?
Is there any oil or lube on the threads for the plugs in the head that is not Dielectric...affecting the ground?
Is your car tuned or have a bigger turbo?


I am guessing it didn't need the R8 coils. Those have a resistance of 5.31 M ohm. The OEM stock coils are 3.3 M ohm. Generally the R8 are used for higher boost when one suspects the arc is getting blown out....and they also gap the plugs to 0.024" to 0.026". OEM coils are meant to burn longer with a larger plug gap of 0.032 or 0.8mm. If Tuned, OEM coils may require a plug gap of 0.028" or 0.7mm. The NGK BKR7EIX are preset at 0.032".

Thank you for replying the coils are the red top r8 coils from Bosch the car has a 3” catless dp, cold air intake, and bov. It has stock turbo and is not tuned. I cleaned everything in there our best I could so I don’t think there’s any oil or lube left affecting it. I had just seen other people who said that upgrading to these coils are better and have a friend with basically the same car that has not had problems with them whatsoever. I’m not saying your wrong I’ve just never heard that before.

 

[Gticed]

Thank you for replying the coils are the red top r8 coils from Bosch the car has a 3” catless dp, cold air intake, and bov. It has stock turbo and is not tuned. I cleaned everything in there our best I could so I don’t think there’s any oil or lube left affecting it. I had just seen other people who said that upgrading to these coils are better and have a friend with basically the same car that has not had problems with them whatsoever. I’m not saying your wrong I’ve just never heard that before.

I’m also thinking I’m going to try to do carbon cleaning on it this weekend and see if that helps but I’ll definitely look into what you’re saying thank you.

 

[doc280]

Make sure to check all your vacuum lines, a vacuum leak will cause all kinds of misfire conditions. The age of these cars are making the vacuum lines fragile, I had the brake booster vacuum line fall apart when I touched it last week.

 

[ROH ECHT]

"I’ve been having misfires for the past month...."

Again...are you seeing the misfires in data, stored fault codes, or are you feeling them?
Here's my point; On a car that is over ten years old....and all of a sudden it has misfires. A different coil isn't the fix unless the coils are in need of replacing. New coils regardless of stock or R8 would've fixed it. The OEM coils do the job they are meant to. I still run oem coils on mine with a K04 at 340hp and 363 lb*ft and have only replaced one of the coils in 14 years and with 155k miles. So yes, new Red R8 coils will work, and do wonders, if it simply needs new coils. But so would stock coils. You never hear someone say they "all of a sudden have misfires on their ten year old car...and I replaced the stock coils with another set of stock coils and it still misfires. Then I tried R8 coils and it magically was fixed." No. New coils, be they stock or R8, would've fixed the issue if the original problem was coils failing.

So you have added new coils and the problem exists.

Injector cleaner doesn't really work. And yes, it may be too much build-up on the intake valves. So this is a good next step if they have never been cleaned before.

If intake valve cleaning doesn't resolve it...you may need someone to check data for fuel trim values. You can look at fuel trims and in most cases it will tell you if there is a leak;

Or do as suggested and give it a thorough visual inspection to see if anything is obviously wrong.

 

[Gticed]

Make sure to check all your vacuum lines, a vacuum leak will cause all kinds of misfire conditions. The age of these cars are making the vacuum lines fragile, I had the brake booster vacuum line fall apart when I touched it last week.

Ill be sure to check all these thank you.

 

[Gticed]

Again...are you seeing the misfires in data, stored fault codes, or are you feeling them?
Here's my point; On a car that is over ten years old....and all of a sudden it has misfires. A different coil isn't the fix unless the coils are in need of replacing. New coils regardless of stock or R8 would've fixed it. The OEM coils do the job they are meant to. I still run oem coils on mine with a K04 at 340hp and 363 lb*ft and have only replaced one of the coils in 14 years and with 155k miles. So yes, new Red R8 coils will work, and do wonders, if it simply needs new coils. But so would stock coils. You never hear someone say they "all of a sudden have misfires on their ten year old car...and I replaced the stock coils with another set of stock coils and it still misfires. Then I tried R8 coils and it magically was fixed." No. New coils, be they stock or R8, would've fixed the issue if the original problem was coils failing.

So you have added new coils and the problem exists.

Injector cleaner doesn't really work. And yes, it may be too much build-up on the intake valves. So this is a good next step if they have never been cleaned before.

If intake valve cleaning doesn't resolve it...you may need someone to check data for fuel trim values. You can look at fuel trims and in most cases it will tell you if there is a leak;

Or do as suggested and give it a thorough visual inspection to see if anything is obviously wrong.

I understand this completely and yes I am getting codes for the misfires and feeling them. I know the oem ones would work perfectly fine but i didn't think these ones would cause an issue as I know other people with the same setup. I knew it didn't actually need them. I will look more into the fuel trims thank you.

 

[BoostedMK5GTI]

Checking a tune that always worked is not gonna do the job.
Check your cam follower of your high pressure fuel pump (they tend to fail over time).
Do you have a friend with a spare lpfp? Try swapping it, parts fail overtime, tunes dont.