# Bank One Misfire in Cylinders 1, 2, & 3.



## MrEd (Oct 29, 2003)

I have a 2000 V6 manual transmission ATQ engine. I am NOT getting a CEL. My VAG-Com indicates that cyclinders 1, 2, and 3 all have intermittent misfires, especially on cold starts. I don't think I would have noticed them without VagCom telling me the misfires exist. Sometimes cyl 1 will have the majority, sometimes cyl. 3. Never does cyl.2 lead the pack, but it does register misfires. The misfires disappear when I am driving. My readiness code shows everything is cool.
I have ruled out spark plugs(new), plug wires(new), coolant temperature sensor(new),ICU (90% sure), vacuum hoses(new). I have recently(5 months) replaced all four oxygen sensors.
My mother in law lost my Vag Com interface back in October so I haven't been able to run fullscale VagCom tests. I am using Shareware right now.
UPDATE******************************************** ****
I have replaced the Bank 1 combi-valve, replaced the bank 1 valve cover gasket, and cam chain tensioner seal and gasket ( I had the leak that causes the oil smell inside the car). SAIP checked out perfectly.
The Combi Valve pipe was sooted up but I didn't clean it. Could this be an issue with misfires even though the valve is new? Is there a way to clean that crap out of the pipe with some type of additive?
I still am getting the misfires at cold start and at idle after the SAIP goes through it's process. So, I am wondering: Would the ICM only cause misfires in cylinders 1-3? Since 1 is on opposite side of 6, 2 opp.of 4, and 3 opp.of 5--wouldn't the most likely scenario be that the section of the ICM that controls 1 would also show cylinder 6 with misfires?????????
I have read how to test the ICM by spraying it with water and no sparks are visible in the dark.
Would one of my oxygen sensors on bank 1 possibly cause the misfires? Maybe one of my new ones is bad?
Bank 1 cylinders 1-3 compression test show 175 psi each.
Bank 2 cylinders 4-6 show 185 psi each. 
Is this difference in psi from bank 1 to bank 2 relevant in my misfire problem??????????????

Anybody have any thoughts at what I could look at next?

_Modified by MrEd at 1:32 AM 4-12-2009_


_Modified by MrEd at 12:15 AM 4-13-2009_


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## Slimjimmn (Apr 8, 2006)

*Re: Bank One Misfire in Cylinders 1, 2, & 3. (MrEd)*

you might want to check the compression again, the spec is 90-95psi. 
I would recomend getting a VERY GOOD top engine cleaning with BG products and the fuel addative. I am sure you have lots of carbon buildup on the valves and piston tops causing cold start detonation. Make sure its a slow vacuum cleaning where it uses engine vacuum to draw in the cleaning solution. (you can use seafoam to do this yourself, just buy some vacuum hose 3/8 inch and there it is plug off the intake pipe on the driver side down low its blue, remove it and put the vacuum hose on there then a vacuum t and the other end and some more smaller say 1/4" hose into the seafoam bottle and run the engine till the can is gone. If the car starts bogging down take the vacuum hose out of the seafoam container so the engine can rev up a little.)


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## MrEd (Oct 29, 2003)

*Re: Bank One Misfire in Cylinders 1, 2, & 3. (MrEd)*

Bentley indicates the compression spec for my ATQ engine is 131-203 PSI.
I did a Seafoam couple of days ago. No noticeable difference in driveability.


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## Slimjimmn (Apr 8, 2006)

*Re: Bank One Misfire in Cylinders 1, 2, & 3. (MrEd)*

Bently is wrong on the spec psi.
you did the chain tensioner gasket, did you remove the cams or just slip the gasket in? if you pulled the cams you might have mis aligned the cams (or maybe forgot to plug the tensioner back in??)
Did you try clenaing the port on the head or the transfer pipe under the valve when you did the combi valve? You might have pushed the carbon chunks into the port and clogged it all the way.??

Edit did you seafoam the intake or put seafoam in the gas tank?



_Modified by Slimjimmn at 10:08 AM 4-18-2009_


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## redinlady (Jun 11, 2007)

When my o2 sensors were bad I had a misfire.
That may/may not help


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## nhdubber121 (Feb 24, 2009)

*Re: Bank One Misfire in Cylinders 1, 2, & 3. (MrEd)*

had the same problem. was a cat on its way out. finished it off by doin a de-carb. the weird part was that the cat had been replaced only 3k ago. to test cat, put the car up and disconnect both muffler clamps after the cats and let them hang. the exhaust stream will probably be weaker from the bank 1 cat and you should be able to feel the diff. with your hand. cats are warranteed for 8/80k good luck


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## faheemo (Apr 6, 2009)

*Re: Bank One Misfire in Cylinders 1, 2, & 3. (nhdubber121)*

Any solution to the issue of the miss on bank 1 ? 
My 2.7T does the exact same thing.
Cylinder 1 or 3 logs missfires never 2.
changed 02 sensors, ign modules , plugs etc... 
ideas ?


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## emanuel fresh kidd (May 5, 2009)

i have that problem too


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## emanuel fresh kidd (May 5, 2009)

*Re: (emanuel fresh kidd)*

any solutions ????


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## Consch-Hofman's (Feb 5, 2004)

have a similar issue on a 98 Audi a4 2.8L v6/5v,156400 miles. ECU p# 4D0 907 551 AH. this vehicle misfires at idle only on cylinder 1,2,3 There is no misfire above 1000 rpm. also if the engine is loaded below 1000 rpm (by idleing down the street in gear) the misfires disappear. Plugs and wires have been changed. injectors have been swapped bank 1 to bank 2 Coil pack has be swapped for a known good one. Plug wires have been inverted on coil pack. cranking compression is 
1 200 4 180
2 205 5 160
3 195 6 170
Fuel trims are under +- 3%
Although the ECU reports to Vag Com miss fires, seat of pants says they are firing but very inefficiently. Misfires this bad (the count in measuring block 15 climbs to more than 100) should result a lot of excess O2 which should show up in the idle fuel trim. Any ideas
thanks in advance
Conrad S.


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## Slimjimmn (Apr 8, 2006)

*Re: (Consch-Hofman's)*

i am sure the valves and piston tops are carboned to ****... its a common 30v v6 issue.


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## the_mad_bastard (Aug 22, 2001)

*Re: (Slimjimmn)*

I've seen similar codes before when the timing was off. First time was a timing belt tensioner that had failed on a car that was close to its TB interval. The next time was a guy that had had his timing belt done by a backyard mechanic that didn't have the correct tools to do the job. 
Might be worth a look...


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