Missfire

Hey guys, I bought my car just over a year ago, and the whole first winter it would spontaneously missfire on all cylinders at once, no power and sputtering but it wouldn’t die. It lasted for 10-60 seconds at a time randomly and only happened once a month or so. It seemed to stop all summer and now that its cold and maybe wet it did it 3 time this month. Ive already replaced my spark plugs and fuel filter and I’m thinking coils. Someone told me coils can intermittently do this. I want to see if anyone’s experienced this and if you recommend coils.

You sure can’t tell by feel that it is misfiring on all cylinders. Have you thrown specific codes?

The best advice I will give you is to invest in a VAGCOM cable. The. You can review all codes or misfires even if they were intermittent. Once you do that it will also be easier to get help by way of the forum, because we could all sit here and randomly guess what your problem is. Sure coils can cause a misfire…or injectors…or just a bad connector somewhere. Sometimes it is a process of elimination, but actually seeing the codes will help a lot more.

^ I can feel a 3.0 misfiring sporadically. It feels like a Fronttrak transmission jerking at part throttle. But I only had to fix almost a hundred or so of those crappy cars. Actually the first step to diagnosing a bad Fronttrak transmission was to go drive the car and look for misfires because it was such a common problem. So I also strongly recommend getting a vagcom cable and log the channel 14-16 measuring value blocks. What I would have given to be able to do that while I was still at the dealership because the factory scan tools can’t log values!

Usually sporadic misfires on a 3.0 were caused by the ignition coils. Have you had the 28F2 ignition coil recall done? If not or you can’t remember then I would call your local dealership with your VIN number handy to see if it is still open for your car.

When I had my shop pull codes every time I get 7 codes, intermittent missfire, and then intermittent missfire cyl 1, cyl 2, ect…

Once and only one we got a code for some vaccum sensor, but when I asked about it on audizine they said thats only on 1.8t.

I also have code for bad cat bank 2 but thats been there since before. Maybe thats got something to do with it?

Personally I’m pretty sure its either coils or injectors. But I think more likely coils. I’ll have to look at the records and see if the recall was done.

Its s good chance it coils. Post tbe coil part number. There was several revisions you might still be on a prone to fail version

I just stopped into a dealer and they said they were done a year ago under the recall. They suggested running some injector cleaner in the fuel and sold me some for a few bucks.

Do had a Vag cable on it at the dealer as its still missfiring, we saw that cyl 1 is missfiring even though you cant feel it all the time. So I purchased my own cable and I am going to move the coil packs and see if it follows the coil or not.

I would start by replacing your 02 sensors to get rid of the codes for your cats. If your coils were done a year ago they are likely not bad, I would check your plugs first.

Plugs changed a few months ago along with valve cover gaskets. We also saw that bank 2 (other side that the missfire) cat was the bad one and we were attempting to test the o2 sensor or another sensor. I’m not sure what he was doing but he went through like 4 screens where he pressed a button and floored the car and it gently accelerated and some numbers either changed or didn’t and he was on the 2nd to the last one when he got kicked off.