P0304
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P0304
I have a 2008 audi a6 3.2 Quattro. I’ve replaced the spark plugs and power coils this past may 2023.
This past week in September, the check engine came on and I got a P0304 code for a cylinder 4 misfire. Now the car runs smooth with no misfire or rough idle or lost of acceleration.
I thought it might be the fuel injectors but why only in cylinder 4. I also had the valve casket cover replaced this past March.
Could it be the oxygen sensors?
I’m not sure what it is at this point.
This past week in September, the check engine came on and I got a P0304 code for a cylinder 4 misfire. Now the car runs smooth with no misfire or rough idle or lost of acceleration.
I thought it might be the fuel injectors but why only in cylinder 4. I also had the valve casket cover replaced this past March.
Could it be the oxygen sensors?
I’m not sure what it is at this point.
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From: Canada
If you suspect injectors then the easiest thing to start with is add a bottle of high quality direct injection fuel cleaner to a tank of premium fuel. If the misfire continues then pull the coil pack and look for oil accumulating in the spark plug wells.
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When I replace the spark plug and power coil last may, it did have some oil in the chamber. I cleaned it out and also had the valve casket cover replaced.
I will buy the fuel injector cleaner and try that.
I’m not sure what else to do if the spark plug chamber has oil in it when I open it again.
I will buy the fuel injector cleaner and try that.
I’m not sure what else to do if the spark plug chamber has oil in it when I open it again.
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From: Canada
If oil in plug wells is present then look close after pulling the coils. If you see oil coming from and seeping below the cam girdle to cylinder head seam then the cam girdle gaskets need to be replaced, or try the temp fix to silicone in some aluminum inserts. There was a post here recently that talked about the patch approach.
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From: Aldie, VA
I have a 2008 4.2. Over the summer, I started getting a misfire in one cylinder only. Swapped coils, no change, did a carbon clean, no change. Then went back in and pulled all the injectors. Once was really bad off but still working. I cleaned them all with a pulser and fuel injector cleaner. Runs like butter nice. Super smooth and my MPG went up by almost 2 MPG (on the highway - this is a V8 after all). You definitely want to make sure oil is not getting into the spark plug holes. That will cause you all kinds of grief.
Not sure what clogged the one injector but based on what I saw, no fuel injector cleaner in a can would have unclogged it. HERe is the writeup I did on my misfire saga. https://www.audiworld.com/forums/a6-...3044007/page2/.
Not sure what clogged the one injector but based on what I saw, no fuel injector cleaner in a can would have unclogged it. HERe is the writeup I did on my misfire saga. https://www.audiworld.com/forums/a6-...3044007/page2/.
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Now even with my cylinder 4 misfire error code - I feel and see no difference in my car’s performance. There’s no rough idle or startup or rev of the rpm’s.
If it was a fuel injector problem then wouldn’t I have a rough riding engine?
If it was a fuel injector problem then wouldn’t I have a rough riding engine?
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From: Lake Tapps, WA
I installed those aluminum sleeves in my 2006 A6 Avant 3.2L V6 in June when I replaced the valve cover gaskets. The company that makes and sells these sleeves is www.audioilleak.com. There is a video on their website that shows how the sleeves are installed to prevent oil leak between the idiotic cam girdle and the head.
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From: Canada
This is all speculation until you do some checks. For example when was the last decarb service?
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I’m getting the diagnostic computer today and I’ll run some more test on it. I did the autozone test and that’s where the misfire on cylinder 4 was read.
the cylinder 4 misfire happened this past March and that’s around when I got my spark plugs and power coils replaced. Then it drove fine and still drives fine but the P0304 showed up again this week.
sorry to say but I haven’t gotten a carbon cleaning. I should but moneys tight right now.
I’m looking into the aluminum sleeve that you insert into the chamber to prevent oil leak from the cam griddle.
the cylinder 4 misfire happened this past March and that’s around when I got my spark plugs and power coils replaced. Then it drove fine and still drives fine but the P0304 showed up again this week.
sorry to say but I haven’t gotten a carbon cleaning. I should but moneys tight right now.
I’m looking into the aluminum sleeve that you insert into the chamber to prevent oil leak from the cam griddle.