[kbrenny]

I purchased a super clean 2006 Touareg a few weeks ago. While it is very clean it had high mileage (260k) and some issues that need attention. I don't want to sink a ton of money into this just to find out it is a lost cause, so I am doing things one problem at a time. VCDS pulls up 28 codes. My biggest concern at this time is "misfire cylinder 4". I know it needs front pads and rotors, and it also needs new tires. I am not concerned with these until I get the engine codes resolved and running properly. No codes on transmission or transfer case. No leaks of any kind.

What I have accomplished so far:
1. Removed intake flaps shaft "bushings" cleaned lubed and reinstalled very smooth now.
2. Installed two new intake flap control linkage rods (aluminum version)
3. Ran the pressurized BMW fuel injection cleaner through for 20 minutes
4. Flushed motor with 2 cans BG products EPR engine flush
5. Changed engine oil with Mobil 1 5w30 and Mahle oil filter.
6. Installed 2 new Mahle air filters
7. Removed cleaned and reinstalled both MAF sensors
8. Ran compression test with following results:
cylinder compression
1 170psi
2 172psi
3 165psi
4 162psi
5 162psi
6 165psi
7 167psi
8 175psi
9. Installed 8 new Denso iridium spark plugs (checked gap at .040")
10. Installed 1 new ignition coil on cyl 4 (misfire cylinder 4 code present at start)
11. Replaced cracked hard plastic line on passenger side of engine bay (vacuum I think)
12. Removed drivers front door lock module and replaced micro switch
13. Replaced sunroof motor
14. Installed new H8 battery
15. Removed a penny and a dime, had jammed the power seat mechanism on pass side
16. Replaced broken Drivers door interior pull handle.
17. Vacuumed all the leaves from the under hood fuse/relay area.
18. Installed 2 new hood lift supports


I cleared all the codes with VCDS and took it for the first drive after all the work.

I am still getting 28 codes. I want to concentrate on the major ones first.

I am still getting a misfire cylinder 4 code even with the new coil pack and spark plug.
I plan on swapping injectors between 4 and 3 next to see if the misfire moves. If it doesn't I would have to think it is a wiring or ground issue.

I also have several codes for the bank 1 sensor 2 Heated O2 sensor. I have a new Bosch O2 sensor ordered and it will arrive in the morning.

I hope (as I have already ordered the part) this is the passenger (right) side O2 sensor after the cat.

The engine runs great but the misfire has me concerned. You cant "feel" it but the code keeps coming up.

Of the 28 codes scanned with VCDS many are for modules detecting "voltage below threshold". I hoped a new battery would clear these up but it did not. Alternator is charging at 13.9 volts.

Any input, ideas or suggestions are greatly appreciated.

 

[edognight]

Well keep at it guess. I just picked up a touareg today and I am in the same boat. I have previously did a cc and it had a boatload of codes and ran terrible after new timing chain and tensioners, so I did new coils, injectors and plugs and the thing is more stable than a coffee table. I think because your compression is all pretty good, it will just be tenacity and details, and you will get it running good... I used to think coils, injectors and plugs were either good or bad, binary, now I see that it can be a shade of grey...Codes with these cars are everywhere. If you fart too loud they will set off a cabin air pollution code.

 

[17_AllTrack]

You said you installed a new ignition coil on cylinder 4 already? Ignition coil was going to be my guess for cause of the misfire. With that mileage I would throw on all new coils

 

[edognight]

You said you installed a new ignition coil on cylinder 4 already? Ignition coil was going to be my guess for cause of the misfire. With that mileage I would throw on all new coils

could be an injector, I think these injectors are semi famous for leaking/clogging

 

[edognight]

btw, answer to your question YES YOU CAN!!

 

[kbrenny]

I replaced the B1 S2 O2 sensor and while working on that I noticed the PCV valve diaphragm was shot. Clogged with gunk and the rubber was almost like a goo. Replaced that while I was in there. Now it runs even better and I do not have any check engines lights or codes. The check engine light did come on briefly while I was revving it up in the driveway tonight, but it turned off within 60 seconds or less. I will scan it tomorrow and see. Whatever was setting the misfire cyl 4 has greatly improved. If it is still #4 I will swap #4 and #3 injectors and see if it moves.

I also found 6 wire "splices" under the carpet at the drivers feet. These were factory and were just bare copper and only had the cloth electrical tape on them. It looks like the sunroof drains had a previous issue that someone fixed but not before the corrosion had already done its damage. I repaired those wires and I hope it eliminates some of the "glitches" I am pulling up with VCDS.

I also found a bad Headlight leveling sensor on the left front. Bad corrosion that had destroyed not only the sensor but the plug that goes into it. Ordered one from a salvage yard out of state with wiring pigtail and should have that in next week.

Just out of curiosity I also checked all the fuses in the left, right and under cowl fuse panels. There were two fuses that were missing (removed) and 3 that were blown. I replaced all 5 and none of them has blown yet so possibly another set of issues resolved.

I did write a lengthy post about removing the B1 S2 O2 sensor if it is being difficult. I cant imagine one being much more difficult than this one was.

Replaced one of the tail lamp bulbs (left one on the rear hatch) and eliminated another status issue on the MFI.

The dash Is starting to resemble a Christmas tree less every day.

I still know I have to do front brakes and possible the rears. The fronts have very little pad left but are warped very badly. Still need to inspect the rears. After that and the Headlight Range Control issue and I should have everything cleared up.

I love the sound the 4.2 makes, one of the best sounding V8 engines I have worked on. Although I am highly surprised you can hear the engine over the sound of it slurping down the fuel. I put $25 in it the night I bought it and drove 55 miles home. Twice after repairs I have driven my 12 mile "see if its fixed" route. This makes the total driven 79 miles and I am almost at 1/4 tank already. I guess I am just used to my 1.9 ALH diesel that gets 48 to 56 MPG.

 

[kbrenny]

I never swapped injectors between #3 and #4. I ran a pressurized BMW fuel injection cleaner (awesome stuff) though the fuel rail at the beginning of this. Once I removed the fuel rail and inspected the back side of the intake valves it was obvious the #4 injector is not spraying properly. Every other cylinder has an intake valve that has a clean shiny backside. The #4 cylinder looked fairly carboned up. I've seen worse but it definitely did not get the fuel injection cleaner like the 7 other cylinders. Bad news is in the process of removing the fuel rail, on three of the injectors, the tan plastic washer on the bottom tip, that helps hold the lower O-ring in, broke off. I don't know what the consequences would be if I tried running the engine with those plastic "washers" gone from the tip of the injector. So I ordered 3 reman injectors. I am just lucky that #4 was one of the ones that broke so it was getting replaced regardless.

 

[Volkswagens-for-life]

You'll get more responses at club touareg

 

[kbrenny]

I posted this over at club touareg also. You probably wont believe it, I have gotten more responses on vortex than there.

 

[lmcgrath]

I have had the 4.2, it is an excellent engine but consumes gas like a drunken sailor on leave for the first time. 12-14mpg is what you can expect when a running normally.

There is also one big, very expensive problem that is common to these motors. Replacing the chain and all the guides is a motor out repair. If one of the plastic guides breaks the chain can fall off and can grenade the motor. Depending on where you live expect to spend 4-5K to have this done. Since you just acquired the car, ask prev owner if they have any record of having this done.
From this article


4.2 V8 Timing Chain Failure Symptoms

• Cylinder misfires
• P1340, 17748 engine codes
• Rattling from the engine
• Limp mode

 

[lmcgrath]

I posted this over at club touareg also. You probably wont believe it, I have gotten more responses on vortex than there.

That makes sense, this forum has a good mix of folks that like driving the cars and good bunch of folks with both interest in the mechanicals and years of experience solving issues.

 

[kbrenny]

Just to post the fix I found to my misfire cylinder 4:

This is probably not going to be a common problem or repair for most but it was just my luck.

I installed a set of new (reman) injectors and still had misfire cylinder 4.

Pulled out my noid light set and checked #4 (should have done this first)

No pulse signal to #4 from the ECU.

I removed the ECU, checked that there was no corrosion on the connections and that everything looked good. Then I started unravelling the insulation on the smaller ECU connector going toward the firewall. Pin 88 (Brown / Green) wire had no damage all the way to the firewall. I was just about to start uncovering the wiring from the firewall to the engine / injector and decided to actually de-pin the terminal and inspect the female pin.

I could tell someone had been in this wiring harness before from the poor quality job they did taping it back up. Sure enough when I pulled terminal 88 out of the small ECU connector it was fairly mangled. It looked as if someone was trying to probe it with something too large and damaged it pretty good.

Luckily I has some VW wiring harnesses in the shed and a terminal from a 2003 Jetta TCU was the same size. I created my own "repair wire" and low and behold I now have a firing injector #4. I verified this with the noid light but have yet to drive it until tomorrow. If this didn't fix my misfire I will re-post here but I am 99 percent sure it is resolved.

I remember an old mechanic I worked with telling me a story about chasing zebras when you should be looking for horses. This is one Zebra I should have chased but it is such an unthinkable problem my mind never went there.

 

[Volkswagens-for-life]

Holy crap, good find man!

 

[lmcgrath]

Just to post the fix I found to my misfire cylinder 4:

This is probably not going to be a common problem or repair for most but it was just my luck.

I installed a set of new (reman) injectors and still had misfire cylinder 4.

Pulled out my noid light set and checked #4 (should have done this first)

No pulse signal to #4 from the ECU.

I removed the ECU, checked that there was no corrosion on the connections and that everything looked good. Then I started unravelling the insulation on the smaller ECU connector going toward the firewall. Pin 88 (Brown / Green) wire had no damage all the way to the firewall. I was just about to start uncovering the wiring from the firewall to the engine / injector and decided to actually de-pin the terminal and inspect the female pin.

I could tell someone had been in this wiring harness before from the poor quality job they did taping it back up. Sure enough when I pulled terminal 88 out of the small ECU connector it was fairly mangled. It looked as if someone was trying to probe it with something too large and damaged it pretty good.

Luckily I has some VW wiring harnesses in the shed and a terminal from a 2003 Jetta TCU was the same size. I created my own "repair wire" and low and behold I now have a firing injector #4. I verified this with the noid light but have yet to drive it until tomorrow. If this didn't fix my misfire I will re-post here but I am 99 percent sure it is resolved.

I remember an old mechanic I worked with telling me a story about chasing zebras when you should be looking for horses. This is one Zebra I should have chased but it is such an unthinkable problem my mind never went there.

Well done, let us know if that fixed it. Your collective experience really paid off or it sounds like it did.

 

[kbrenny]

Update, I thought it was the connection at the ECU, but it started misfiring again (cyl 4). I checked for signal in the wiring harness about 2 inches from the ECU and it was dead. I believe now it is a bad ECU. From what I have been told by someone who really knows Audi / VW ECU's, there is a separate "chip" on the board for each injector. I would guess that is the problem. I mailed my old ECU and a used (known good) ECU to someone swapped their software / programming for my Touareg. The "new" ECU is sitting on my workbench waiting to be installed. I ran into some health issues 2 weeks ago and have been occupied with ER trips and Doctor visits. Starting to feel better and looking forward to getting back on fixing the Touareg. I will post again once the "new" ECU is installed with the results.

 

[qualls]

Wishing you a speedy recovery, and hoping you get the Toureg running smoothly. I have been considering buying a 1st-generation Toureg or Cayenne, but am worried about lots of minor repairs consuming a huge amount of my time and money. Reading your experience in this thread is encouraging. . . In hindsight, if you could go back in time, would you purchase another 1st-gen Toureg? Or do you think it would be better to pay a bit more for a 2nd-gen Toureg?

 

[lmcgrath]

I had 2004 with the 3.2 v6. Loved it, beautiful road car and had zero issues. Did not take it off-roaring because it was too nice. Yes I would buy one. The 3.2 was smallest engine and it did have to work pretty hard. I drove the V8 that came out in 2005. That is what I would buy. However in 2011 they put the 3.0TDI in them and it is a wonderful powerplant for this suv. You get huge power and good mileage. The gas engines are all very thirsty in this suv because it weighs around 2.5 tons when loaded.

 

[kbrenny]

I have been an avid TDI fan / owner / enthusiast for 14 years. My plan as of now is to sell the Gen 1 Touareg V8 once it is all fixed. Then I plan on purchasing a Gen 2 TDI Touareg. I have 3 friends who all own TDI specialty repair shops in Texas and from their experience and opinions I want to get a 2013 Touareg TDI. I am not saying anything against the Gen 1 but the Gen 2 has some options I really wanted and the 3.0 TDI had some changes for the 2013 model year that my friends all said was worth going after specifically.

 

[lmcgrath]

I have been an avid TDI fan / owner / enthusiast for 14 years. My plan as of now is to sell the Gen 1 Touareg V8 once it is all fixed. Then I plan on purchasing a Gen 2 TDI Touareg. I have 3 friends who all own TDI specialty repair shops in Texas and from their experience and opinions I want to get a 2013 Touareg TDI. I am not saying anything against the Gen 1 but the Gen 2 has some options I really wanted and the 3.0 TDI had some changes for the 2013 model year that my friends all said was worth going after specifically.

Yes, I have a 2014 A8 with that motor and a Malone Stg2 tune and it rocks. Almost 500ftlb torque really moves the car and still get 625-650 miles per tank.

 

[kbrenny]

I would love an A8 TDI Quattro but for my situation I need a larger rated towing capacity.