rough idle and multiple codes

2010 AUDI A5
186,000 MILES • 4 CYL • TURBO • 4WD • MANUAL
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
Has several codes and misfiring:

P2279/
p050700/
p30100/
p30200/p
30200/p
30400

Is it possible carbon build up?
Nov 7, 2021 at 2:53 PM
Advertisement
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
Hello, can you be clear on the codes again, are you saying, P2279, P0507, P0301, P0302 and P0304? Any Codes P0301-P0304 are cylinder misfire codes per cylinder, i.e. P0301 Cylinder #1 Misfire etc.
Also, do you have access to your own scan tool?
Nov 8, 2021 at 8:51 AM
Avatar
KASEKENNY
  • CERTIFIED EXPERT
  • 18,907 POSTS
Just to add to this, if you have misfire codes on multiple cylinders and the P2279 which is an air intake temperature code which is most likely caused by an air leak then we need to start with this.

More than likely you have a leak on the charged air side of the turbo. Basically, if you are losing pressure from the turbo to the intake it will cause a rich condition and you can have a misfire.

Basically, it thinks there is a certain amount of air coming in and matches that with fuel but if there is a leak then you will not have that much charged air and so it be a rich condition.

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Let's monitor the o2 sensor data and see if you are on the rich side and then use soapy water on the charge tube to look for bubbles.

If this all checks out, then I am attaching the testing for this code which is what we need to run through.

Lastly due to the rough idle, we should check for a vacuum leak. This is a similar test but here is a guide for checking for a leak:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Let us know what questions you have.

Thanks
Nov 8, 2021 at 12:22 PM
Advertisement
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
Makes sense. Thanks to you guys.
Nov 8, 2021 at 12:28 PM
Avatar
KASEKENNY
  • CERTIFIED EXPERT
  • 18,907 POSTS
No problem. Let us know how it works out. Thanks
Nov 8, 2021 at 12:49 PM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
First thing i did was wash the motor, there is so much oil/dirt around the coils, there may be oil in the wells due to cover gasket, have not checked yet. Deleted all codes, first one's came back as misfire coil 4 and p0070 ambient air temperature circuit.
Nov 10, 2021 at 1:11 PM
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
Ambient Air Temperature Sensor is labeled the Outside Air Temperature Sensor. This is going to be a 5-volt sensor with ground. I'll put up the diagrams for it.


https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring
Nov 10, 2021 at 1:47 PM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
Yes, it's the only hard code i see. I switched coils and now it says 2 instead of 4, so the rough idle is definitely at least caused by this sensor, may be other things but it's a hard code.
Nov 10, 2021 at 2:42 PM
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
But this is the first time you've gotten this code, correct? It's strange those others would disappear and a completely different one show up. How is the wiring harness on this thing, you don't notice any contact points where it may have rubbed threw the harness at all? On this Outside Air Temp Sensor, you should have 5-volts on the green/white wire and the other green/brown wire is a shared ground circuit. If you unplug the sensor and just lightly touch the pins, never jam a multimeter lead into a connector, you should have 5-volts with it disconnected. Thats it 5-volt reference wire (or feed). These sensors are usually on the front of the car, most of the time in the front grille area. You'll be able to identify it by its wire colors. This code is for a circuit issue. If you're missing its 5-volts, then there may be a wiring issue, corroded connector, etc. That would explain the other random codes. And by switching the coils around you've identified that it's a bad coil causing that misfire. Smart move by the way, moving that coil.

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring
Nov 10, 2021 at 2:57 PM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
No, this code was among the ones that were there before. And for now, most of them disappeared, but they may reappear. I will check on the sensor.
Nov 10, 2021 at 3:06 PM
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
okay, it may be like Kenny said, the turbo boost pressure is leaking and you're not getting other codes because you're just not driving it right now, The P2279 is an Intake Air leak code, and definitely can be coming from the turbo leaking into the intake. We call vacuum leaks "false air" because the ECM doesn't see them, but the oxygen sensors will and the ECM will increase fuel due to that, therefore causing a rich misfire.
Nov 10, 2021 at 3:08 PM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
very possible. I only started it for few minutes, I can hear the turbo when revving the motor. hopefully, it's not carbon build up as I do not like doing blasting, but with 186,000 its possible. not sure where all the oil came from on top of the valve cover, not side where it should leak. maybe from filling oil during these years and some seeped under the cover.
Nov 10, 2021 at 3:10 PM
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
Can you post a decent picture of it? Is it near the oil supply line for the turbo? In yellow is the supply line and red is the return line.
Nov 10, 2021 at 3:13 PM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
And spark plug looks okay, not wet or dark.
Nov 10, 2021 at 3:18 PM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
I think the sensor is on the intake side above the throttle body. Checked it with my probe and got ground and 4.5 number. Also cleaned it out. Cleaned MAF as well and checked on air filter. Checked turbo boot and is ok. Used water and soap sprayed everywhere around hoses, intake, nothing changed. Lifted the oil cap to see if its maybe PCV, bit it's easy to remove. Deleted codes and only got them all back under pending code, only one that keeps coming back as stores is the air sensor. Pending codes are misfires 1-4, which is expected when engine idling this rough. The rough idle is only when left idling, once i give it a touch of gas everything smooths out.
Nov 11, 2021 at 6:57 AM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
Also found this PCV diaphragm busted but doubt it can cause all of that.
Nov 11, 2021 at 7:32 AM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
Here you go.
Nov 11, 2021 at 7:32 AM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
I changed it, made no difference. Also noticed that the fan is on and on high when A/C is off and car is cold.
Nov 11, 2021 at 8:19 AM
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
Something else I noticed that is strange, are those live data readings with the car running? Because all your fuel trims are reading 0, which is not good, either the scan tool is not able to read all the data, or the ECM doesn't have full control of the fuel system. The sensor on the Intake is the Intake Air Temperature sensor, the Outside Air Temperature sensor is ambient outside air used mostly by the A/C system. Thats what the p0070 code is for, so you had 4.5 volts with the Intake Air Temperature sensor unplugged? that's a little low for the 5-volt reference circuit,
So, what are all the codes you're getting right now? pending or not.
the fan issue may be because of that ambient air temperature sensor being out of range, since it's part of the A/C system.
Go down to the APP sensor on the gas pedal and just check to see what the 5-volt reference is down there. On that sensor, (its 6 wire) you should have two 5-volt ref feeds.
Also looking at the Front 02 sensor, which is a wideband sensor is reading 0.980mA, that's indicating a lean fuel mixture, so that's still pointing at a vacuum leak here. Usually for a vacuum leak like this that you couldn't find with soap and water, i would use a smoke machine on the intake, I'm assuming you don't have one?

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge
Nov 11, 2021 at 8:29 AM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
It just says 4.5 didn't make a beep or a green light. All pending are misfires on all and the p0070. I will check on the pedal sensor.
Nov 11, 2021 at 8:53 AM
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
I'm not sure how accurate these numbers are but I do see a Short-Term fuel trim bank 1 sensor 2 of 99%, depending on how this ECM calculates its fuel strategy, either that's a lack of correct data, or the ECM is adding fuel to a lean mixture. The FRP (fuel rail pressure) looks within spec for idle, it should go up to 2,000PSI with higher RPMS.
Nov 11, 2021 at 9:07 AM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
I will use another scanner.
Nov 11, 2021 at 9:08 AM
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
Do you own a smoke machine? Seems you do have some diagnostic tools..
Nov 11, 2021 at 9:11 AM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
Yes, i have a smoke machine.
Nov 11, 2021 at 9:19 AM
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
Have you tried smoking the intake? block off the throttle body and any ports that will allow smoke to escape, of course you'll see those when your smoke pressure starts to build up, but that's your best tool for a vacuum leak, or disprove one..
Nov 11, 2021 at 9:26 AM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
Here are some data with ignition on. Mag code is there cause i disconnected it to clean it. Will send some data and video while running.
Nov 11, 2021 at 10:54 AM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
Also with ignition on engine off.
Nov 11, 2021 at 10:55 AM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
While running.
Nov 11, 2021 at 11:15 AM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
Am going to smoke it next.
Nov 11, 2021 at 11:25 AM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
I always have a hard time finding the right place to insert the smoke pipe. would you attach it to one of the PCV hoses?
Nov 11, 2021 at 11:33 AM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
Did a smoke test and there is a leak but i can't see where its coming from? It's on top of the catalytic on passenger side. Can't see a thing from bottom. Wondering if you can check diagrams to see what can be that the fan causes this leak. My luck. It can't just be a normal leak on top of the motor that i can see, lol.
Nov 11, 2021 at 12:11 PM
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
I couldn't see any of the data on that other scan tool, it cuts the screen in half when its sideways. as for the smoke machine, I would avoid the PCV system because you want to check that for leaks as well, they seem to leak more than anything to be honest, You can go into the throttle body as long as you're able to seal it up around the hose, or the brake booster, I don't know the exact setup of your vehicle, You can send a picture of the engine facing directly down on it, I'm having trouble locating a decent picture..

Okay, well, wow that's a huge leak, is there part of the turbo down in that location? I can't believe how much smoke you're getting. are you sure there isn't a crack in the exhaust either? It's really hard to see from that angle. I'm watching the video a few times,, see if you can shoot another from a different angle, I've been looking for vacuum line diagrams and can't find much on Pro Demand, I will keep looking though.
Nov 11, 2021 at 12:22 PM
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
It looks like the Turbo comes right off the end of the exhaust manifold, you're going to have to get under there and get a real good look, possibly turn the smoke down some so that you have a small amount, it's almost impossible for me to pinpoint it from a video. There's just so many hoses down in that area, Turbos make it tough, i fully understand the frustration, but at least you found something. Just need to ID that part.

Where did you go into with the smoke machine?
Nov 11, 2021 at 12:33 PM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
No, it isn't coming from the exhaust, if it was it would have been obvious to see, and a sound would be different.
Nov 11, 2021 at 12:39 PM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
I will try with less smoke and see. It's jacked up high but the 4wd blocks everything, you can't see a thing from down below.
Nov 11, 2021 at 12:43 PM
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
These are the type pictures I keep finding on ProDemand. Most are not even labelled components.
Nov 11, 2021 at 12:53 PM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
I dialed it down. Keeps coming from underneath a silver metal hose which i think has harness inside it which is underneath the exhaust manifold which also runs on top of the transmission as well.
Nov 11, 2021 at 1:08 PM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
There is also a ton of oil down there around engine and transmission and am thinking it maybe the rear main seal has gone really bad and created this leak. Am doomed.
Nov 11, 2021 at 1:10 PM
Avatar
AL514
  • CERTIFIED EXPERT
  • 5,463 POSTS
Well, there is also the oil feed and return lines for the turbo down there, with that much smoke, I don't think it would be the rear main seal, more like a broken oil line for the turbo, a rear main would leak that much smoke.

So, in orange is the Oil Feed line and in green above it is the oil return line, I had to grab this picture off a video.
Nov 11, 2021 at 1:22 PM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
But isn't the picture showing lines towards the front of the car? I see the crank pulley.
Nov 11, 2021 at 1:59 PM
Avatar
DIVIDES
  • MEMBER
  • 903 POSTS
Am going to pressure wash the bottom tomorrow and see.
Nov 11, 2021 at 2:15 PM