Misfires on 2014 Audi A4, Critical Flashing Engine Light

[jbera1997]

I bought this audi a couple of weeks ago from a dealer in town. It originally had some misfiring at idle on the lot. I told them about it before buying it and they said they had fixed it, and for the second test drive it seemed fine. I purchased the car and left the dealership and the very next morning it was misfiring again and a check engine light came on. I took it back and they said it was the spark plugs (which is what they said the first time) so they replaced them again and it seemed fine. I had flushed the coolant because they had the wrong kind in and the next day it was misfiring really bad again at idle so I got some codes from an obd2 and it didn't reveal much info, only misfire codes. My roommate and I checked the spark plugs again and revealed that the dealer had put cheap autolite spark plugs in, so we replaced them with Bosch double platinum and everything was running smoothly. Today I went to start the car and warm it up to head to a business meeting and it started misfiring badly again and shot me a blinking check engine light, which I understand is not good. This is what it was doing around the time I replaced the coolant as well, I'm aware that it has nothing to do with the coolant flush but I'm not getting any specific codes. It only misfires on idle and is a lot worse in the cold. Engine vibrates and shakes the car at times. At operating temp, the car is fine. I can attempt to find a more in depth diagnostic tool to see if I can figure anything out but I decided I would check here first. Afraid to start it up, let alone drive it at this point. Starting to feel like I got ripped off 😅. Any suggestions?

[jbera1997]

Edit: engine vibrates/shakes at idle, only when cold. No misfires while driving, or shaking while driving, only at idle. When at operating temp, can't notice anything at all. When idling engine ticks or riddles some, softly. Can hear it better when you pop the hood. Timing chain maybe? I bought it at 98k miles and doubt it's been changed even though I expressed my concern with the dealer I bought it from. Ignition coils look good. Very minor corrosion, probably built on old spark plugs from before the dealer even got it. A clip on one of my fuel injectors is broken, might replace fuel injectors as well. Seems like it's rare to find anyone in my area who knows anything about audi/VW. Just want some input on what I should be looking for to replace before I spend buckoo bucks on things the engine didn't exactly need replaced

[JLAllroad]

Edit: engine vibrates/shakes at idle, only when cold. No misfires while driving, or shaking while driving, only at idle. When at operating temp, can't notice anything at all. When idling engine ticks or riddles some, softly. Can hear it better when you pop the hood. Timing chain maybe? I bought it at 98k miles and doubt it's been changed even though I expressed my concern with the dealer I bought it from. Ignition coils look good. Very minor corrosion, probably built on old spark plugs from before the dealer even got it. A clip on one of my fuel injectors is broken, might replace fuel injectors as well. Seems like it's rare to find anyone in my area who knows anything about audi/VW. Just want some input on what I should be looking for to replace before I spend buckoo bucks on things the engine didn't exactly need replaced

Are the codes for random misfires or just mostly one cylinder?

Are you running E85?

What make and part# PCV?


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[jbera1997]

Are the codes for random misfires or just mostly one cylinder?

Are you running E85?

What make and part# PCV?


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I'll have to take a look at the pcv tomorrow and get back to you. I've been replacing small parts and chasing this since I bought the car. The dealer I bought it from continues to say it's the spark plugs. They've replaced them twice and I've replaced them once. Each time the misfires stopped and then started again a few days later. The dealer keeps telling me to bring it back in but something tells me they don't have any idea what they are talking about or doing.

I've pulled codes after each misfire and it seems to be just misfiring at random. I believe the first time was 1, 2 and 4. The second time was all cylinders. This most recent time (today, 2/14) I pulled:

P0506
Idle control rpm low

P0300
Random/multiple cylinder misfire

P0303
Cylinder 3 misfire

P0304
Cylinder 4 misfire

P0302
Cylinder 2 misfire

P0506
Idle control system rpm low

It's only misfiring in idle? And not always? But when it does I refuse to drive and it just sits. The engine is also a little noisy, almost sounds as if tension on the belt or timing chain is loose? Or the engine running is rattling something with broken clips? Unsure. The guy I've been constantly talking to about it has owned an audi before and worked on them. Said he can't help me though because he doesn't have time. He told me today it sounds like a timing belt issue and I should probably replace it. Gonna be pretty costly in my area, if I can even find anyone who will do it correctly. Doing it myself is going to be a hassle as it's starting to snow again here and I don't have a garage I can push it into. Nor do I have the proper tools for the job. I'll take a look at the pcv and get back to you asap.

[jbera1997]

Are the codes for random misfires or just mostly one cylinder?

Are you running E85?

What make and part# PCV?


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Add: I'm running 91 premium

[jbera1997]

Pcv is audi OEM

PA6-GF30
06H 103 495 AE

Kind of hard to read, looks like the original part and it's kind of worn in

[jbera1997]

Would it be wise to grab a new oil separator with the part number 06H 103 495 AK, or should I dip into audi oem and empty my pockets

[JLAllroad]

Would it be wise to grab a new oil separator with the part number 06H 103 495 AK, or should I dip into audi oem and empty my pockets

Ideally use OE Audi, although FCPeuro has the Hengst (OE manufacture) at a significant discount.

https://www.fcpeuro.com/Audi-parts/A...=&keywords=Pcv

This is a 15min job, if you can do plugs you can do this, 9-10mn torque in the sequence below, do check the hoses that go to the PCV as they can crack/leak and become the cause of idle issues.
IMG_8615.jpg

A way to test for a completely failed PCV, pull the oil cap while idling, there should be significant suction and the engine should stutter a bit, if either aren’t the case it is probably mostly working.

That said, I do consider the PCV a maintenance item above 80k miles.

P0506 causes
Dirty throttle body
Intake air leak
Electric throttle control actuator misadjusted or damaged
Faulty Electric throttle control actuator
Poor electrical connection to the Intake Air Control (IAC) valve


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[jbera1997]

Pulling the oil cap, there was definitely a crazy amount of suction. Any experience with UroParts? Cause I've already ordered the 06H 103 495 AK
https://www.urotuning.com/products/o...32052886634551

If it doesn't help, I'll return it and spend some more money. Haven't been able to find any noticeable leaks in hoses, no oil leaks. Oil is full but looks like it needs changed, that'll be next on the list

[JLAllroad]

Not only do I not recommend non OE PCV’s, I’m absolutely against using them.


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[canonball]

How many miles on the car? Is this the 2.0? Possible carbon build up issue?

[jbera1997]

I bought it with 98k, been having the issues since 24hrs after buying it.

[canonball]

I bought it with 98k, been having the issues since 24hrs after buying it.

Ah, yeah just saw in your second response where you listed the mileage and that the post is in the 2.0 tech thread, sorry about that oversight.

You've already checked spark plugs, I think you mentioned checking the coil packs, right?

A clip on one of my fuel injectors is broken, might replace fuel injectors as well.

This is a big job on the 2.0s, if you're going to do this I'd count on doing a carbon cleaning as well while you're in there and don't forget to pick up an IM gasket. You can try running a fuel additive (G001780M3) to a full tank and doing some spirited driving. I did this about once a month and it helped for a bit on my '10 VW CC 2.0t but after a while I ended up doing the cabon cleaning. Runners and valves were gunked up with carbon. After the cleaning it ran SO much better, no more misfires, CEL cleared itself, and it was a happy camper.

Not sure if this is the culprit for you but something to consider. Direct injection engines are known for this issue so something to be aware of. I wouldn't be surprised if the dealership knew this when they sold it to you