New Member: 2006 S4! Help, I already broke it!

[phrisco]

Hey Everyone! I just picked up my new-to-me 2006 B7 S4 on Saturday, but then I screwed up. While putting my new License Plate on, I locked my only key in the trunk. I paid a locksmith to come to my house to break in. The Locksmith went through the drivers side door, when he got through, the Immobilizer kicked in, so the trunk switch remained disabled. Insread of going through the rear seats (DUH), I figured I'd just reset the ECU via battery unplug(Disconnected the positive terminal, pressed the brake to get rid of residual charge, then reconneted the positive terminal). Obviously that didn't work for the security, and turns out, unlike Japanese cars, German cars don't like that. My car then became angry.

After that episode, I went for another drive, got a Check Engine Light blinking then static, and the car got a little rough after 3000rpm. After I got home, I researched the ECU reset, and foudn the proper steps for the Throttle Alignment. SO I did that, heard the proper noises during the process, etc. CEL remained.

I checked the Oil Dipstick, and it seemed a little low on Oil. So I put about a qurt in, and now it looks like the Oil is a tad high. Reset the ECU and went through the steps again. Went for another drive. It seemed good, but then I went into higher RPMs, the CEL blinked a bit, but then went away. I tried that a few times, and eventually the CEL became static again.

Possible Problems:

1. The car is in limp mode because it thinks it's stolen.
2. The only aftermarket mod is a Milltek Catback Exhaust. The ECU knows there's something different. The car is actually fine but I need to force off that CEL.
3. I blew a coilpack(s). I'm new to V8's, so I can't tell if it's misfiring at idle or not. Already the car idles rougher than any 4 or 6 banger I've driven in the past 20 years.
4. Something else. Keep in mind I took the car for a good drive before I bought it. The owner let me abuse it a bit and everything was cool. The previous owner also seemed very geniune and sad to see the car go. I don't beleive myself to be completely naive, but of course there's always that chance I bought a lemon.

Has anyone had a similar scenario? Any ideas?

I have purchased a VAG-COM cable and a OBD2 reader, but they don't arrive from Amazon until tomorrow or Wednesday.

Thanks!

[AudiTechS4]

ok first you need some sort of hand help scanner for any real help so when you get those post up codes. immobilizer only has to do with the starting of the car , nothing else. central locking when locked will not allow you to use the trunk button.

for the misfire most likely a coil gone bad , when the check engine light flashes thats for misfires - it went solid because you hit the misfire counter threshold of something being faulty.

[phrisco]

Could a coilpack blow due to reconnecting the battery? Feels like a crazy coincidence that this would happen minutes after I disconnected/reconnected the battery to reset the ECU.

Does the Milltek catback exhaust throw a CEL unless otherwise disabled?

Does this car have a limp mode? Could that be enabled causing the engine to misfire purposefully?

I was able to get my hands on 4 coilpacks. Should I just replace one side, and if that doesn't work, replace the other side? Will the CEL magically go away if the issue is fixed, or do I have to reset the ECU again? (I guess I should disconnect the battery before replacing Coilpacks, huh?)

Thanks again!

[AudiTechS4]

exhaust wont cause misfire or code unless you have after market cattless down pipes but the code would have been there the whole time.
not it wont cause it to misfire purposefully .
if you have the coils and want to , more power to you but while your in there might wanna replace the spark plugs if they were not done at 55k.
better to wait for the scanner so you dont waste 3 coils.

[phrisco]

Thanks for your replies! It's appreciated!

If I go ahead with the coilpack replacements. I should disconnect the battery first, correct?

Therefore, if I fix the problem, the ECU will reset and the CEL won't show from memory, it just won't occur, correct?

[phrisco]

Also, wouldn't the car also misfire at idle if a coilpack was faulty?

[jakeoboy67]

exhaust wont cause misfire or code unless you have after market cattless down pipes but the code would have been there the whole time.
not it wont cause it to misfire purposefully .
if you have the coils and want to , more power to you but while your in there might wanna replace the spark plugs if they were not done at 55k.
better to wait for the scanner so you dont waste 3 coils.

my misfires were from my exhaust (clogged cat)

[Bonz099]

Dude, pull the codes FIRST!!! Otherwise you're shooting in the dark. If you plan on keeping the car, you MUST have some kind of vagcom cable (even a cheap one) to pull codes from the different modules, this won't be the last time you need to pull codes ;)..... Many codes wont be read by a simple odbd2 scanner and many wont through a CEL.

[phrisco]

Dude, pull the codes FIRST!!! Otherwise you're shooting in the dark. If you plan on keeping the car, you MUST have some kind of vagcom cable (even a cheap one) to pull codes from the different modules, this won't be the last time you need to pull codes ;)..... Many codes wont be read by a simple odbd2 scanner and many wont through a CEL.

I ordered this; Lemonbest Car Auto Diagnostic Scanner KKL VAG-COM 409.1 ELM327 USB AUDI OBDII OBD2 Cable Tool New
https://www.amazon.ca/gp/product/B00...?ie=UTF8&psc=1

and this; Veepeak Bluetooth OBD2 Scanner for Android, Mini OBD II Diagnostic Adapter, Car Bluetooth OBD2 Code Reader Scan Tool for Check Engine Light (MIL) Trouble Code & Live Sensor Data - Support Torque
https://www.amazon.ca/gp/product/B01...?ie=UTF8&psc=1

I hope they work. I'm not sure which software to get for the VAG-COM.

[macattac]

I have a OBD2 scanner for my droid....works great.....hope you'll sort the problem out!!

[phrisco]

So I pulled the code. Misfire on #8. I replaced the coilpack. Cleared the code. Start the car, immediate CEL, misfire on #8. I pulled the plug;

http://i.imgur.com/nBATvIP.jpg

Previous owner tells me he's never changed the plugs wtf. I pick up new plugs tomorrow, NGK 5767.

I look down the cylinder with a flashlight and it looks like quite a bit of carbon on the top of the piston. Any additive recommendations? I hope it just needs a little TLC. I swear when I test drove it, the car drove beautifully. I believe 0.01% of people out there ruin it for the remaining 99.99%. He still answers my texts, I fail to believe he's a bad guy until this proves otherwise. I think he's just car-dumb.

[IslandHydro]

You should probably do a compression / leakdown / boroscope, these things are prone to cylinder scoring

[jakeoboy67]

that sparkplug is impressive, in a bad way lol

[Bonz099]

ummm, that oil and carbon is not a very good sign at all..... do what IslandHydro said ASAP and at least do a compression test immediately. Its very clear that oil is entering the cylinder. I would ask him to take the car back if I pulled a plug like that.......seriously.... good luck man...

Heres a good tester to minimize your costs so far. https://www.amazon.com/INNOVA-3612-C...ression+tester

[phrisco]

I changed the plugs last night, cleared the codes, and all went very smoothly. I'll still do all the compression tests, rad leak tests, oil change, etc. this weekend. But, so far, so good.

[phrisco]

Update: Based on symptoms, I'm pretty convinced it's a valve stem seal in Cyl8. I'm planning on finally doing the compression test this weekend, but still pretty convinced of my diagnosis.

Anyway, if I'm right, I'll pull the heads and replace the gaskets, etc. I'll probably have a shop do it, but I'd be grateful if anyone knew of a DIY on the net somewhere. (I am capable of doing it myself.)

Also, any advice on what should be replaced if I have the heads off? The timing chain was done at 107k km and currently has 156k km, so I don't think that's an issue? I'm probably replacing the AC Compressor since my AC don't work. No leaks in the system and the AC driveshaft is turning. Should I get a valve job done? New valve guides? Anything else? Again, I'm grateful for any advice. Thanks!

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