pavarolar

I got a 2007 A6 Quattro with 4.2l FSI engine with 122k miles on the clock.
The bad news is that it is not drivable. I have been trying to diagnose it and now I need some advice of what i should check next.

Here is the symptom with my A6

It is running very rough and will not accelerate passed 50 mph.
I am seeing flashing CEL light and white smoke coming from the passenger exhaust pipe.

Got home and can tell that it is fuel that is coming out the pipe (white smoke and strong fuel smell).
Here are the codes: P0302 - Cylinder 2 misfire detected
P2293 - Fuel Pressure regulator 2 performance
I did the following diagnostic the next day:

Test 1 - Check if it is an issue with Spark Plug on #2
- Removed the Spark Plug (#2) noticed it looks brand new. I just had spark plug and coil replace about a month earlier.
- Check Spark Plug #3 just to compare and it shown sign of combustion (dark/carbon deposit).
- Just to make sure if Spark Plug #2 is bad, I swapped it with #3 (If it is a bad plug, misfire should move to #3)
- Clear code and ran the car again, it is still showing the same fault codes Misfire on #2 and Fuel regulator 2.
Conclusion = Spark Plug #2 is good but still no spark on #2

Next Test 2 - Check if coil #2 is bad.
- Removed Coil from #2 and put it in #3. If the coil is bad, the fault code should now jump to misfire on #3.
- Clear code and rant the car again. Same fault codes came up Misfire on #2 and Fuel regulator 2.
Conclusion = Coil #2 is also good.

So, I am not tested and learn that both Spark Plug #2 and Coil#2 are working but I have no ignition on cylinder 2.
Where should I go next? Is it the ECM, Relay or something else that send out the signal to ignite cylinder 2??

And what about Fuel regulator 2 fault code? This car has the high-pressure fuel pumps and I can see that it is pumping fuel (seeing it spaying out the back of the passenger exhaust pipe. This is why I was going after the missing spark route first, but is this a sign of something wrong with the high-pressure pump also?

Looking for some insights that some on the forum might have from their experience.
Again this is 2007 A6 Quattro 4.2l FSI with about 122k miles.

Thank you so much.

raj99

What's your coolant look like? Check your expansion tank and let us know what your level is.

LarryJa

Run a compression test on that bank of cylinders.

pavarolar

The coolant level looks fine, I don't see any sign of coolent lost. The smoke coming out smells like gasoline.

raj99

Sounds like your fuel injector(s) need to be changed if that's the case. Basically they aren't atomizing the fuel and your getting too much fuel spewing through and I bet your plugs smell like fuel as well and are wet. If this keeps up your going to create a fire risk in the cat convertor and could damage, if they aren't already, your O2 sensors.

pavarolar

How hard of a job is it to change fuel injector(s) on this Audi? Are there any diagnostic tasks that I should try to do to make sure it is an injector issue before doing the work?

raj99

Search is your friend, here you go: https://www.audiworld.com/forums/sea...rchid=10672790

I'd also advise you do a full VCDS log pull and post it with all the error codes.

John Crowley

Hi raj99, I have the exact same problems (and unfortunately... maybe more after you read this) as pavarolar except my coolant tank was down (abt half) last week and I am getting crazy codes now (UO100 Lost Communication with ECM/ PCM Acylinders #5,6,7 and 8 cylinder misfire. #'s 6, 7 n 8 Ignition coil F, G and H Primary/ Secondary circuit.
PO2293 Fuel Pressure Regulator. PO2015 Intake Manifold Runner Position Sensor/ Switch Circut Range/ Performace 1a. PO2020 Intake Manifold Runner Position Sensor/ Switch Circut Range/ Performace 2a. The car is now dead. Oh, and there was gas in the oil pan. I drained my (2007 A6 Quattro 4.2) oil because the smell of gas (I checked the oil and smelled it instantly) was concerning me. The drain plug was on so tight, I almost didn't get it off (I used to compete in powerlifting competitions - I am still very large and brutally strong just to emphasis how tight the drain plug was on) but when I did (didn't strip it or anything, it looks perfect) It was crazy. Long story short, after some oil/ gas, went on the ground because I couldn't get additional oil pans faster enough the car filled up a 5-gallon pal of oil/ gas!

Backstory. I literally bought this car Dec. 1 of 2019 (as in 2 months ago). The car has 108k miles on it. The engine was spotless (too clean now that I think of it)- interior and exterior were/ are immaculate. I did the carfax on it, it looks like it has had all the routine and schedule services and he told me (he is a 1 man show, but incorporated) that he just did the 100K mile service (That was the only reason I bought the car) on it. The first night I brought it home, I noticed a little oil drip on the right side of the passenger side, so I called him up and told him... he said: "Oh, Audi's burn oil, just keep an eye on it for a couple of weeks." I have heard Audi's burn oil, but an oil drip is different, but I said OK let's see what happens (Should've driven the car back then and there... Coulda-Shoulda-Woulda). about 3 weeks later I'm on the highway and the car starts acting up (yep, obviously, it ran out of oil... no warning, no nothing), it wouldn't accelerate, seemed to be starving for fuel, all the "I'm outta oil pull the F over as soon as you can n get oil" signs. So I fill the oil reservoir (made sure I didn't overfill it either) and call the guy up...

I went to his mechanic Jan. 2 on He says: "oh, that's strange, bring it to my mechanic and have him take a look at it". So I did it... I don't think this guy was an Audi Certified Mechanic mind you. I told the mechanic what happened and he throws it on the lift (I stay in the bay so I can see what's going on) and takes the skid plate (that's what I call it-the undercarriage cover in the front?) off and there are oil stains (still is... wet stains) all over it... Mechanic diagnoses the problem as an oil separator (tells me to come back on the 6th)...

Jan 6th shows up, and so did I... at the mechanic's shop. I had to wait outside for 10-15 as both his bays were occupied... Then it's my turn, I start the car and instantly the check engine light comes on, so he checks it, it came up as misfire #8 cylinder- Ignition Coil. He said: "You should be fine if the car is acting up bring it back" and clears the code. He fixes the Oil Separator and sends me on my way.

Between Jan 6th and 25th, this is where I notice the engine coolant is low (took half a bottle of the Audi recommended antifreeze) and I fill it up with the correct antifreeze.

Jan 25th it all goes bad... Gas in the oil (I think antifreeze too because of the pics below - Leak looks like Ice Coffee under the car, from the oil pan). Now my car won't start, batteries dead... I think I know what you are going to say, but I need to hear it from a mechanic.

the coffee milk leak 1

the coffee milk leak 2

This is the original leak when I brought the car home.

raj99

Hi @John Crowley I just looked at the pics and hate to be the bearer of bad news, but that looks like the tell-tale signs of a blown head gasket. That also explains where your anti-freeze is going. Get that car on a lift at a place that specializes in German vehicles (VW/Audi) and they should be able to diagnose very quickly. BTW, never trust a very clean engine...I've owned my car for I don't know how long and I've never "washed" my engine...any dealer doing as such is hiding something.

John Crowley

@raj99 Yep. That’s what I figured, just needed to hear it from someone who knows a helluva lot more than I do. Ah, I think I’m going to have a very direct discussion with the *** clown who sold me the car. I have just had it 2 months, and everything is documented (problems starting night 1)... I want my $ back. He can do what he wants with the expensive paper weight.

I was planning on putting the oil I drained out of it this weekend (if you remember, the oil drain filled up a 5 gallon bucket plus the oil that got on the ground- it is now only a half full, I’m figuring most the gas dissipated), and dropping the car off at his mechanic.

I think I should be able to jump it (it’ll smoke like James Bond’s Jag but it should run ... like crap... but run) and get it going. Or do you think it could cause a bonfire with all the gunk that’s on/ in the engine, etc.?

Question for you, what causes the head gasket to blow? Here’s the add the kid posted for the car... I kind of feel like he and the mechanic knew... which makes me angry... very angry.




UOTE=raj99;25416423]Hi @John Crowley I just looked at the pics and hate to be the bearer of bad news, but that looks like the tell-tale signs of a blown head gasket. That also explains where your anti-freeze is going. Get that car on a lift at a place that specializes in German vehicles (VW/Audi) and they should be able to diagnose very quickly. BTW, never trust a very clean engine...I've owned my car for I don't know how long and I've never "washed" my engine...any dealer doing as such is hiding something.[/QUOTE]