Misfires

[bigbseehagen]

So I have a B6 S4 with 125k miles. It started to misfire this past Sunday. I detailed the car on Saturday so it would look nice for the weekend. It was running good till Sunday afternoon when it would shake at an idle and the CEL would start flashing. I had to drive it home and the CEL stayed on now. I got home and my buddy has a computer and he pulled up codes P0300 then P301,P302,P303. So we changed the spark plugs to iridium NGK and cleared codes. Drove it around and ran great for 30 minutes. Then the idle shake came and it felt worse. Ran the codes and now 301,302,303,305,307. What is happening and why would 2 more cylinders start misfiring after replacing plugs?? Help. I have the coils on order should be here this weekend!

[S4orgy]

i was going through the same thing man coilpacks may be a waste of money honestly. i spent money on plugs, coil packs, ecs intake gasket and though they all made my car feel better the cel like kept coming back. its either cam adjuster is on its way or Tensioner. "stop driviing it before it gets worse" i had p0300,p0305, p0307, and p0308. car just died on me one day and got codes for camshaft sensor. replaced it- and it did nothing then got cam sensor code for pass side after i replaced the driver. so i decided to do compression and my pass side came in at 155,152,150,145 and driver side was close to 0. now im hoping i dont have scored cylinders or bent valves. def time to do the timing on it

[S4orgy]

my car was shaking like a wet dog and idling like it was cammed. and would stall under load

[brooklynA42004]

I had the same problem but if I immediately shut the car off and restarted it it would run fine, changed all the plugs and coil packs no more misfires.

[0396]

i was going through the same thing man coilpacks may be a waste of money honestly. i spent money on plugs, coil packs, ecs intake gasket and though they all made my car feel better the cel like kept coming back. its either cam adjuster is on its way or Tensioner. "stop driviing it before it gets worse" i had p0300,p0305, p0307, and p0308. car just died on me one day and got codes for camshaft sensor. replaced it- and it did nothing then got cam sensor code for pass side after i replaced the driver. so i decided to do compression and my pass side came in at 155,152,150,145 and driver side was close to 0. now im hoping i dont have scored cylinders or bent valves. def time to do the timing on it

Updates?

[bigbseehagen]

I had the same problem but if I immediately shut the car off and restarted it it would run fine, changed all the plugs and coil packs no more misfires.

What plugs did you use? I used NGK Iridium could that cause an issue?

[mistral cytz]

So I have a B6 S4 with 125k miles. It started to misfire this past Sunday. I detailed the car on Saturday so it would look nice for the weekend. It was running good till Sunday afternoon when it would shake at an idle and the CEL would start flashing. I had to drive it home and the CEL stayed on now. I got home and my buddy has a computer and he pulled up codes P0300 then P301,P302,P303. So we changed the spark plugs to iridium NGK and cleared codes. Drove it around and ran great for 30 minutes. Then the idle shake came and it felt worse. Ran the codes and now 301,302,303,305,307. What is happening and why would 2 more cylinders start misfiring after replacing plugs?? Help. I have the coils on order should be here this weekend!

The idea suggested that your car needs the timing service would be worse case scenario but have you been hearing bad start up rattle cold and warm?

[brooklynA42004]

What plugs did you use? I used NGK Iridium could that cause an issue?

i used the Bosch FGR7KQE0 and updated oem coil packs.

[bigbseehagen]

The idea suggested that your car needs the timing service would be worse case scenario but have you been hearing bad start up rattle cold and warm?

Yes the rattle is pretty bad on startup and only for 1-2 seconds though. On a warm engine not so much only sometimes.

[bigbseehagen]

i used the Bosch FGR7KQE0 and updated oem coil packs.

Are those single prong or 4 prong?

[dparm]

Are those single prong or 4 prong?

FGR7KQE0 is a quad-electrode and one of the OEM plugs.

You can use NGK Iridiums if you want, won't be a problem as long as the gap and heat range are correct. I ran Denso Iridums with the 0.4mm ultra-sharp tip (sharpest sold today) and it ran perfectly, as I expected.

Related thread that explains the various OEM/OEM-equivalent plugs:
http://www.audizine.com/forum/showth...-through-12-31!

[brooklynA42004]

Are those single prong or 4 prong?

4 prong, I also had multiple misfires and the engine ran like crap making all sorts of warm start noises.

[pagrosse]

In my opinion, spark plugs would not cause this issue nor correct this issue. I'd look at them as more of a 'wear' item and typically will only effect MPG and maybe some form of performance difference (either between worn plugs or different types and styles of plugs, i.e. NGK, Bosch) Unless the electrode is completely blocked or shorted will there be intermittent issues causing misfires which is Extremely rare and would only occur on 1 cylinder, not multiple. The chances of multiple spark plugs and/or multiple coil packs being defective all at once is 1 in a 1,000,000.

Additionally, when multiple misfires exist, across a bank or the entire engine, this points to something that is:
Common to the bank - timing is all I can think of OR
Entire engine - both bank timing, MAF, vacuum leak, fuel pressure, etc.

NET: most likely your timing has skipped a tooth = engine removal and timing chain service and possibly head rebuild if contact was made

I think everyone tries the easy things, spark plugs/coils because its easy and relatively cheap but ends up disappointing and has to face the unfortunate truth of the design flaw with these engines...

[pagrosse]

BTW, bigb, did the misfire/CEL/shake all happen just after a start? Or did it happen while it was already running?

I'm trying to build the case that the oil check valves can significantly reduce the likelyhood of this event (cam timing skipping a tooth) from ever occurring.

[brooklynA42004]

In my opinion, spark plugs would not cause this issue nor correct this issue. I'd look at them as more of a 'wear' item and typically will only effect MPG and maybe some form of performance difference (either between worn plugs or different types and styles of plugs, i.e. NGK, Bosch) Unless the electrode is completely blocked or shorted will there be intermittent issues causing misfires which is Extremely rare and would only occur on 1 cylinder, not multiple. The chances of multiple spark plugs and/or multiple coil packs being defective all at once is 1 in a 1,000,000.

Additionally, when multiple misfires exist, across a bank or the entire engine, this points to something that is:
Common to the bank - timing is all I can think of OR
Entire engine - both bank timing, MAF, vacuum leak, fuel pressure, etc.

NET: most likely your timing has skipped a tooth = engine removal and timing chain service and possibly head rebuild if contact was made

I think everyone tries the easy things, spark plugs/coils because its easy and relatively cheap but ends up disappointing and has to face the unfortunate truth of the design flaw with these engines...

I guess i was one of the lucky ones!!

[pagrosse]

I guess i was one of the lucky ones!!

Interesting... Were you still on the original coilpacks? If so, did you replace all of them with the updated coil pack and new plugs for the issue to go away?

[brooklynA42004]

Interesting... Were you still on the original coilpacks? If so, did you replace all of them with the updated coil pack and new plugs for the issue to go away?

I'm not sure but looking at the carfax some coils were replaced so i just went and replaced them all with the updated red coils from europaparts since the were only $20 ea but the plugs looked original and looked pretty bad so i replaced them too.

[bigbseehagen]

BTW, bigb, did the misfire/CEL/shake all happen just after a start? Or did it happen while it was already running?

I'm trying to build the case that the oil check valves can significantly reduce the likelyhood of this event (cam timing skipping a tooth) from ever occurring.

No not after start. The misfire happens when the engine warms up and then is at an idle in gear. If I put it in neutral it is not as bad. I have the automatic tiptronic version. So if I shift to neutral at a stop light and keep my RPM's above 800 then I'm good.

I get my new coils tomorrow and I'm going to replace the valve cover gaskets and coils. I am going to clean everything when I have it apart. Is seafoam ok to use to clean the plug wholes? Or what should I use. I am also going to clean the injectors as well. I am just wanting to get it up and running again. I haven't even been able to drive it more than 3 times. There is a pretty strong smell after a drive as well I am guessing the cause of the misfires? Gas smell.

[pagrosse]

No not after start. The misfire happens when the engine warms up and then is at an idle in gear. If I put it in neutral it is not as bad. I have the automatic tiptronic version. So if I shift to neutral at a stop light and keep my RPM's above 800 then I'm good.

The question was more directed to when the initial misfire issue occurred. Was it running great one day then the next day you started it up and it ran rough with the issue and misfires? Or did this happen while it was running?

[bigbseehagen]

The first time I noticed it was when I got home from going to the store about 10 minutes away. I was in my driveway in park then it started to have rough idle and CEL started to flash. I turned it off and it went away.

I drove it the next day into town, around town, and back about 100 miles or so. And that is when the light stayed on.

So we tested it and got codes P0300, 01, 02, 03. I went and got new plugs and swapped them out. Then two more codes popped up 05 and 07.

[bigbseehagen]

After I turned it off when the CEL started to flash I turned it back on THEN it went away sorry.

[bigbseehagen]

It also shifts kinda funny in auto from 3-4 gear. In manual mode it doesn't have a problem

[Jake@JHM]

Did you happen to power wash the engine bay?

[bigbseehagen]

No but I'm pretty sure I sprayed it briefly with hose

[bigbseehagen]

Did you happen to power wash the engine bay?

No I'm pretty sure I sprayed it with the hose briefly

[brooklynA42004]

After I turned it off when the CEL started to flash I turned it back on THEN it went away sorry.

mine too hopefully its a coil pack.

[blackedoutt]

Did you happen to power wash the engine bay?

This. I got a front cylinder coil pack wet once and it didn't like it. If you hosed them all, I'm not terribly surprised you have more than one misfire fault. Try swapping coil packs hole to hole and see if the code follows the coil pack. This will be hard with more than a couple cylinder faults though. May be easier just to get a new set and keep old but good ones as spares.

Also with reading blocks 091-094 with VCDS you can diagnose the health of you electronic cam adjusters at least.

[RPMtech147]

It's motor pull time regardless for timing bits and clutch/flywheel. I swear this is the only powertrain I've seen that when 1 part fail its damn near destroys the entire powertrain. Loose a Coil, score a cyl, loose a motor. Loose a chain, loose all the valves. Lose a flywheel, loose the entire transmission. Time to get your hands dirty. Bond with the B6 I say!!!

PS, I lived in Arizona for so many yeas I knew that was good old phoenix sunshine without even seeing your location. So did they manage to put a house on top every square inch of desert yet?

[brooklynA42004]

It's motor pull time regardless for timing bits and clutch/flywheel. I swear this is the only powertrain I've seen that when 1 part fail its damn near destroys the entire powertrain. Loose a Coil, score a cyl, loose a motor. Loose a chain, loose all the valves. Lose a flywheel, loose the entire transmission. Time to get your hands dirty. Bond with the B6 I say!!!

PS, I lived in Arizona for so many yeas I knew that was good old phoenix sunshine without even seeing your location. So did they manage to put a house on top every square inch of desert yet?

wow are these motors made out off glass? next time I break a cup holder should I pull the motor?

[bigbseehagen]

wow are these motors made out off glass? next time I break a cup holder should I pull the motor?

Haha seriously though what the heck! So here is an update!

I replaced all the coils and I got rid of 3 of the misfires! Now there are only cylinder 1 and 3. So I am thinking it has to do with the connectors or something. Another issue I thought of is could it be from the injectors on those two cylinders? Maybe they are flowing through all of the holes? The car runs strong until it idles after driving it a little while. Then the cel light flashes and if you turn it off it goes away on its own. Really weird. I don't get this car!

[bigbseehagen]

Haha seriously though what the heck! So here is an update!

I replaced all the coils and I got rid of 3 of the misfires! Now there are only cylinder 1 and 3. So I am thinking it has to do with the connectors or something. Another issue I thought of is could it be from the injectors on those two cylinders? Maybe they are flowing through all of the holes? The car runs strong until it idles after driving it a little while. Then the cel light flashes and if you turn it off it goes away on its own. Really weird. I don't get this car!

Maybe they are NOT flowing through all of the wholes!

[brooklynA42004]

you can also check if the bolts on you intake manifold are loose

[Concavitor]

Coilpacks

[SlickFix]

My engine sounded off song yesterday while driving, almost like there was a hole in the exhaust system. At idle, all seemed good, so I kept driving.

When a few miles from home, I went through a round-about and accelerated, and it seemed down on power. Then the CEL popped on. My first thought was "Dear god please not the timing chain guides!"

Anyway, here are the codes I pulled:

8 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 008 - - Intermittent
16685 - Cylinder 1
P0301 - 008 - Misfire Detected - Intermittent
16689 - Cylinder 5
P0305 - 008 - Misfire Detected - Intermittent
16686 - Cylinder 2
P0302 - 008 - Misfire Detected - Intermittent
16691 - Cylinder 7
P0307 - 008 - Misfire Detected - Intermittent
16815 - Warm Up Catalyst; Bank 2
P0431 - 001 - Efficiency Below Threshold - Intermittent
17537 - Fuel Trim; Bank 2 (Mult)
P1129 - 002 - System too Rich
16559 - Fuel Trim; Bank 2
P0175 - 002 - System Too Rich - MIL ON

Ironically, the parts for the "miracle chain rattle fix" arrived two days ago, and I'm tackling that job today. I sure hope this isn't the beginning of the chain guide nachtmare.

Yes, I have both cold and intermittent warm rattle.

[mistral cytz]

My engine sounded off song yesterday while driving, almost like there was a hole in the exhaust system. At idle, all seemed good, so I kept driving.

When a few miles from home, I went through a round-about and accelerated, and it seemed down on power. Then the CEL popped on. My first thought was "Dear god please not the timing chain guides!"

Anyway, here are the codes I pulled:

8 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 008 - - Intermittent
16685 - Cylinder 1
P0301 - 008 - Misfire Detected - Intermittent
16689 - Cylinder 5
P0305 - 008 - Misfire Detected - Intermittent
16686 - Cylinder 2
P0302 - 008 - Misfire Detected - Intermittent
16691 - Cylinder 7
P0307 - 008 - Misfire Detected - Intermittent
16815 - Warm Up Catalyst; Bank 2
P0431 - 001 - Efficiency Below Threshold - Intermittent
17537 - Fuel Trim; Bank 2 (Mult)
P1129 - 002 - System too Rich
16559 - Fuel Trim; Bank 2
P0175 - 002 - System Too Rich - MIL ON

Ironically, the parts for the "miracle chain rattle fix" arrived two days ago, and I'm tackling that job today. I sure hope this isn't the beginning of the chain guide nachtmare.

Yes, I have both cold and intermittent warm rattle.

Are you referring to the oil check valves as the miracle chain rattle fix parts?

[SlickFix]

Yessir, those would be the ones. Oil valves, oil jet, o-rings, new gaskets.

[RPMtech147]

wow are these motors made out off glass? next time I break a cup holder should I pull the motor?

The going joke is place the bumper in service mode before airing up the tires. Service mode is a fancy term for pull the front clip but save 20 mins by not actually disconnecting and just putting 10inch bolts in the mounting holes and sliding it back enough to well, not really do anything, It's good for putting new blower pullys on the b8, not so much for b6 s4. I change the belt without moving the bumper. Once it's in service mode, its like 10 more minutes to just remove it all together.

[JimmyBones]

My engine sounded off song yesterday while driving, almost like there was a hole in the exhaust system. At idle, all seemed good, so I kept driving.

When a few miles from home, I went through a round-about and accelerated, and it seemed down on power. Then the CEL popped on. My first thought was "Dear god please not the timing chain guides!"

Anyway, here are the codes I pulled:

8 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 008 - - Intermittent
16685 - Cylinder 1
P0301 - 008 - Misfire Detected - Intermittent
16689 - Cylinder 5
P0305 - 008 - Misfire Detected - Intermittent
16686 - Cylinder 2
P0302 - 008 - Misfire Detected - Intermittent
16691 - Cylinder 7
P0307 - 008 - Misfire Detected - Intermittent
16815 - Warm Up Catalyst; Bank 2
P0431 - 001 - Efficiency Below Threshold - Intermittent
17537 - Fuel Trim; Bank 2 (Mult)
P1129 - 002 - System too Rich
16559 - Fuel Trim; Bank 2
P0175 - 002 - System Too Rich - MIL ON

Ironically, the parts for the "miracle chain rattle fix" arrived two days ago, and I'm tackling that job today. I sure hope this isn't the beginning of the chain guide nachtmare.

Yes, I have both cold and intermittent warm rattle.

Do you still have the stock pre-cats? With those codes I am willing to bet that the bank 2/driver's side pre-cat is clogged up, especially because of the last three and because it seemed down on power.

[JimmyBones]

you can also check if the bolts on you intake manifold are loose

This along with making sure that the MAF boot is on the throttle body fully. Sounds too easy but those MAF boots can be an intermittent PITA sometimes.

[SlickFix]

Do you still have the stock pre-cats? With those codes I am willing to bet that the bank 2/driver's side pre-cat is clogged up, especially because of the last three and because it seemed down on power.

Yes, I believe the exhaust is stock. Your explanation certainly sounds logical. Is there a way to test for a pre-cat clog?