Cylinder 1 misfire since 80k service

[SLCGoth]

Hello BSE,

Long time no talk guys, I wish I could say Atlanta has been treating me well, but that isn't exactly the truth.
Ended up replacing my Mechatronics unit under (the tail end of) warranty. But now I have a new problem.

Ever since my 80K service in November I have been having a sporadic CEL. Always for Cylinder 1 misfire. My local VW/AUDI/Porche shop has been the only place working on it, and so far they have been great-ish except for finding the problem which has grown worse over the last 4 weeks.

Took it in 2 weeks after the service for the misfire code, cleared. One of the head techs thought it was a fluke from them changing my plugs at the service.

Occasionally it would come back for a day or so when it was raining outside so I figured it may have something to do with that. But then the rain stopped. Finally got a steady light and brought it back.

Shop owner saw some tape on my upper radiator hose, and one of the techs saw that a piece of hose that came off cylinder one was missing/damaged. Replaced. Light came back 4 days later.

Brought it in the next week and all 4 ignition coils, cylinder one showed some corrosion or rust on the end of it (but I have no idea how water could have got in to foul it to that extent) the NEXT day, light was back. Took it back in last week.

Last week the shop owner had me leave the car so he could look at it personally, he replaced all 4 spark plugs this time and even showed me the plugs that had been pulled out. They looked like average spark plug wear and tear to me. For the first time since the whole ordeal started the car ran the way it should. No sputtering on cold starts.

Today 2 days after the spark plug repair, I cranked my car after leaving work and she shuddered a little bit. I let the car warm up while I finished a smoke, hopped in, and backed out of my space. Before I was out of the parking lot the light came back again.

I am literally at my whits end on this one. In the last 4 weeks I have paid for 3 different sets of repairs AND changed the gas I have been putting in the car, thinking that my usual station may have got a bad batch.

The code is ALWAYS the same for Cylinder One Misfire. And it always occurs at a cold start.

Any thoughts?

-Blake

[SLCGoth]

Note "last week" for me was actually Wednesday due to my work schedule. Hope that makes a little more sense.

[Mikewire]

I'll excuse the xpost Good to hear from you

Replace the #1 injector, it's probably faulty. If that doesn't fix it then it could be carbon build up, coil harness wiring, or there is a TSB on the lash adjusters on that motor. Both cams come out on that one, and it's a fairly big job. You should probably get it to the dealer for the TSB info and warranty work on this issue.

[SLCGoth]

Even if the car is out of warranty the TSB SHOULD cover it right?

[SLCGoth]

Never mind...my google fu is stronger than that question. If it ends up not being the injector...I may be on the lookout for another car. Something tells me 5 hours (estimate given from googling) at my local dealership, plus parts, may be more than I can rightly afford on a vehicle that has had problems since purchase.

[SLCGoth]

This sounds about right:

Technical Service Bulletin Transaction No.: 2017063/2
01-08-04 - MIL ON, Misfire DTC P0301, P0302, P0303 or P0304 Stored in ECM Fault Memory after Cold Start Release date: Oct 9, 2008

Condition

01 08 04 Jan. 23, 2008 2017063

MIL ON, Misfire DTC P0301, P0302, P0303 or P0304 Stored in ECM fault Memory after Cold Start

At times engine may run slightly rough for a few seconds after cold start. MIL may illuminate with a DTC for misfire on one cylinder only (P0301, P0302, P0303, P0304) stored in the ECM fault memory. Rough running condition disappears a few seconds after cold start and DOES NOT exist with a warm engine.

Technical Background

Not applicable.

Production Solution

Not applicable.

Service

1. Follow normal Guided Fault Finding Diagnosis, for example:

• Swap spark plugs and ignition coils between affected cylinder(s) and good cylinder(s).

• Check compression and leak-down of affected cylinder(s).

• Verify fuel quality. (Also refer to Technical Bulletin 2014815 - Gasoline Quality.)

• Swap fuel injectors between affected cylinder(s) and good cylinder(s).

Note:

When swapping fuel injectors, always replace all fuel injector seals.

2. If diagnosis results are inconclusive, and above mentioned condition persists, replace all 8 Hydraulic lash adjuster (lifters) of affected exhaust side.

Warranty

Information Only.

Required Parts and Tools

For Part No. reference, see table below:

Part Number
Part Description
Quantity

022 109 423 D
Hydraulic lash adjuster
8 (if needed)


06F 103 483 D
Valve Cover Gasket
1 (if needed)

06D 998 907
Sealing Kit for Fuel Injectors
1 (if needed)

Tool Description
Tool No:
Quantity

VAS Diagnostic Tool
VAS 5051 / 5052