Misfire on cylinders 1,2, and 3 NEED HELP

[stoeger92]

I am having a ton of trouble trying to diagnose my misfire problem on my 2001 Passat VR6. It is putting out codes for random multiple misfire, misfire on cylinder 1, misfire on cylinder 2, misfire on cylinder 3. I replaced the coil pack, spark plugs, spark plug wires, fuel filter, checked the compression, checked the timing, and added fuel system cleaner and so far no results. I would appreciate any input on this matter VARY VARY much. Thank you

[jonrp]

have you checked the oil level, if its overfull i can cause misfire codes because the crankshaft hits the oil and slows down for a second....

[DavidVR6477]

Definitely sounds like Bank 1 Cam Adjuster. That my friend is not a fun DIY!

[john prusinski]

I've had a misfire cylinder1 then multipule random misfire. It turned out to be my downstream o2 sensor.

[silverd2]

Definitely sounds like Bank 1 Cam Adjuster. That my friend is not a fun DIY!

I dunno...cam adjuster problem should throw an over retard or over advance code...not a misfire code.

[silverd2]

I've had a misfire cylinder1 then multipule random misfire. It turned out to be my downstream o2 sensor.

That doesn't make any sense...the downstream O2 sensor only checks and reports how the upstream is performing. It does not make adjustments or have anything to do with a cylinder firing.
Did you do the swap yourself or did a mechanic do the work and tell you this?
I'd say he found a simple fix and then milked it for something that was throwing a code.

[stoeger92]

sorry guys i was out of the country for a while and didnt check up on my tread. But in regards to the cam shaft adjuster, i saw a post about someone having a misfire on the same cylinders and that was his problem but he also had a code for a camshaft position sensor while mine only comes up the the misfire codes for cylinders 1,2, and 3 plus the mechanic i spoke to said it would make a distinct noise which he didnt hear. As you can tell I am no expert on Volkswagens but apparently none of the technicians i brought it to are either seeing as they cant find the problem. Im just spitballing here but could it have something to do with the fuel system??

[john prusinski]

That doesn't make any sense...the downstream O2 sensor only checks and reports how the upstream is performing. It does not make adjustments or have anything to do with a cylinder firing.
Did you do the swap yourself or did a mechanic do the work and tell you this?
I'd say he found a simple fix and then milked it for something that was throwing a code.

Family friend mechanic. There was no simple fix I checked everything. Took it to him he checked the codes next day he said I owed him like 70 bucks for an o2 sensor. I don't see why he would lie. He doesn't charge me for labor.

[jonrp]

sorry guys i was out of the country for a while and didnt check up on my tread. But in regards to the cam shaft adjuster, i saw a post about someone having a misfire on the same cylinders and that was his problem but he also had a code for a camshaft position sensor while mine only comes up the the misfire codes for cylinders 1,2, and 3 plus the mechanic i spoke to said it would make a distinct noise which he didnt hear. As you can tell I am no expert on Volkswagens but apparently none of the technicians i brought it to are either seeing as they cant find the problem. Im just spitballing here but could it have something to do with the fuel system??

i take it that the car isnt skipping all the time.. Does it seem to idle rough? especially in park? I doubt it is a fuel problem, but i have seen a few plugged injectors.. but they were always just 1, never 3... If you had an electrical problem with the injectors, you would get a code. What kind of scanner are you using? The generic scanners will ignore some vw only codes... ps.. did you check the oil level? And how long after you clear the codes does it take for them to come back?

[jonrp]

actually, i have also seen plugged cat converters generate this issue.... misfire on only one bank.. ESPECIALLY the cheapy aftermarket weld in kind.. What kind of cats do you have, and how many miles on your whip?

[Mxkmster]

Misfires can be caused by many different things. Normally plugs, and ignition coils are the cause. If you put the wrong plugs in it can do the same thing. Make sure the plugs you put in are laser tip plat. Any other type will cause misfires. Replacement coils should be factory if not same problem. Now on more rare cases catalytic converters have a problem were the inside comes apart inside. The cat willnt fail the basic settings for the rear o2 sensor. When they get really bad a fault for incorrect air flow generally will be thrown. A simple check is pull out the front o2 and run the car and see if the misfires go away. One thing that also does happen is carbon build up inside the engine. If the old plugs were covered with build up you may need to just do an induction cleaning. It works wonders for 1.8t engines.

[stoeger92]

thanks so much for the replies. Im not sure what kind of diagnostic machine was used but i had it diagnosed at Nemer VW and another garage that specializes in vws, Hackels VW, so im sure they were adequate. The car runs great besides the light being on. I dont notice any loss in power or performance. I did check the oil level too and that was right where it should be. Its hard to say how long it takes for the light to come on. If I dont drive it rough, not like to do anyway, it will sometimes take up to 2 days, around 40 or 50 miles. But every time it does come on it will it will flash emissions work shop, the light will blink a few times, and then it will shut off again. This process will repeat many times. I think the most i counted was like 15 or 16 times. There is about 108,000 miles on the car right now. As for the cat, did you say that it was possible for it to not trigger the o2 sensor if it was malfunctioning? I think i answered all your questions but let me know if i left anything out. thanks again

[jonrp]

thanks so much for the replies. Im not sure what kind of diagnostic machine was used but i had it diagnosed at Nemer VW and another garage that specializes in vws, Hackels VW, so im sure they were adequate. The car runs great besides the light being on. I dont notice any loss in power or performance. I did check the oil level too and that was right where it should be. Its hard to say how long it takes for the light to come on. If I dont drive it rough, not like to do anyway, it will sometimes take up to 2 days, around 40 or 50 miles. But every time it does come on it will it will flash emissions work shop, the light will blink a few times, and then it will shut off again. This process will repeat many times. I think the most i counted was like 15 or 16 times. There is about 108,000 miles on the car right now. As for the cat, did you say that it was possible for it to not trigger the o2 sensor if it was malfunctioning? I think i answered all your questions but let me know if i left anything out. thanks again

id say you definately have an ignition skip... where did you get the wires, plugs, and coil pack?? when the CEL blinks, the ecm is registering misfires by watching the crankshaft speed..

[stoeger92]

well the original wires i replaced were autopart international brand...and ngk plugs, but they were replaced at Nemer with stock plugs and wires. The coil pack i got at autozone, but when i went to try to get it diagnosed at Hackels the guy tested the old coil pack and said it was fine so he put it back in.

[jonrp]

well the original wires i replaced were autopart international brand...and ngk plugs, but they were replaced at Nemer with stock plugs and wires. The coil pack i got at autozone, but when i went to try to get it diagnosed at Hackels the guy tested the old coil pack and said it was fine so he put it back in.

definately keep it stock, stock, stock vw parts... they HATE aftermarket parts... especially cheapy autozone advance pepboys crap

[the tech 71]

Considering it's only on one bank of cylinders, it's probably an issues with something they all have in common, such as a plugged cat, or incorrect cam timing on that bank.