[DT_]

Hi all,
New to the forum, first time owning a VW (not really - had a Golf MK2 GTI 10 years ago but that's a whole different game) and not too familiar with common issues and fixes. I have a VCDS but don't know how to use it yet.

Long story short, bought a 2004 V8 a month ago from Switzerland - pretty neat, loving it all round. I have a few issues I researched to the best of my ability but haven't found a definitive solution and was hoping to get some advice from people who've been there.

Note: passenger side fuel pump went bad and I just had it replaced - was pretty sudden and took a while to figure out how the whole system works but all fixed now and the car drives.

1. Check engine light was on ever since I bought it. Code is:
17837 - Circuit for Brake Vacuum Pump
P1429 - 0040 - Open Circuit
I don't have any issues braking. I've read a bunch of threads here on the forum but I could really use some photos to help locate the pump and the hoses - I appreciate that a hose might be loose or cracked and causing the whole problem.

2. ESP light and tough gear changes + kinda weird acceleration pedal repsonse
This doesn't always happen. Sometimes if I don't push the car much it might not come on at all. Most times it does though and once the ESP goes off, gear changes become sharp and it kicks a lot. The accelerator pedal needs pressed quite a bit more too before I get a response and it's usually a pretty sporty one - finding it hard to gently accelerate especially from a stop. Interestingly, I don't have any codes for that - then again I've only done the general fault check in VCDS for all modules.

3. Timing belt last changed before 60k miles - clearly needs changed soon as but thought it might be worth doing along with the chains depending on your advice.

4. Camshaft chain tensioners
I can hear the well-known sound for around 1 second when starting the car from cold - it actually needs more than a day I think, i.e. if I only power it up after 12 hours of sitting, there's no sound. Apart from that odd 1 second of rattling, no other symptoms.

5. A tormenting buzzing sound coming from the dashboard when the lights come on at night. That is, the dashboard lights, headlights are unrelated. Dashboard off - nice V8 sound, dashboard on - slowly going mental.

Summary:
I love the car and want to make sure it's in perfect condition.
I suspect points 1 and 2 are somehow related, 3 and 4 are well-known, just looking for the best approach, 5 not truly important but essential to my mental stability.

Really appreciate any help and advice - good knowledge on these Touaregs seems pretty hard to find - mechanics think it's like any other VW or Audi but it really isn't.

Thanks very much!

 

[SaVAGeSoot]

Please post a complete autoscan as it will contain a whole bunch of clues.

 

[Viking Lady]

Hi and welcome DT-

change your belt and associated items now.

Then get codes cleared. Then drive a bit and get a new full scan done with a VCDS scanner and post issues and scan.

 

[voortreger]

The sound described under 4 is apparently caused by some sort of valve that goes bad and can be replaced but not a simple task. If you search you may find the post. My v8 does the exact same thing and I believe they all do.

 

[DT_]

Hi again,

Apologies for taking a while to come back with a scan.
I'm attaching 2 files below:
1. Auto-Scan (before clearing codes) - mind you, this includes a lot of aftermath of me removing the central console for refreshing the worn-out buttons AND a dead battery after diagnosing the failed fuel pump which included a lot of "power on the car a stare at it wondering why it stalls after 20 seconds".
2. Auto-Scan (after clearing codes) - clearing all codes through the basic function in VCDS then powering on the car, driving around for 10 minutes with a few kick-downs and redoing the scan.

To summarise again:

• Check engine light is always on - car drives ok with the exception of the occassional shake and a bit of stutter under 2k RPM
• ESP light comes on (no pattern, though if pushing the car it almost definitely comes on) - gearbox starts kicking and the stutter and shaking becomes more noticeable

As seen from the scans, the gearbox and the ABS do give out an error saying basically look at the engine errors..

Any help with diagnosing this would be really helpful, mechanics around here are useless and my brand new to VW so assume zero experience.

A (small?) footnote:
Looking at some tutorials on how to use VCDS, I tried checking measuring block 93 to see the state of the camshaft chains and tensioners. Again, I can very briefly (for less than 1 sec) hear a chain rattle only on cold mornings. Aren't the results pretty bad though? Image below.

Huge thanks to everyone for your help!

 

[SaVAGeSoot]

So start by chasing down the MAF problem.

17481 - Mass Air Flow Sensor 2 (G246)
P1073 - 002 - Signal too Low

I would suggest you log its measurement and compare it to the one on the other bank so see if any major deviations jump out.

 

[DT_]

Hi

I may not be the fastest but I'm consistent.

So as SaVAGeSoot suggested, pursuing the MAF issue is the right way to go. Many thanks for that!

Check engine light gone, ESP light gone and a much, much smoother drive. RPM deviation also gone.

However! The vibration/stuttering around 1500 - 2000 RPM persists - I've been advised by some friends that this is a typical bad spark plug indication. I'm having them changed with the next service in a week or two and I'll share the results.

Wrt brake vacuum pump - we did an individual test and it does actually not work. We don't know why but we'll diagnose this after everything else is sorted.


Thanks everyone for your help! I'll make a few more posts here to provide updates until all is fixed so people can use this as reference in the future.

 

[SaVAGeSoot]

So as SaVAGeSoot suggested, pursuing the MAF issue is the right way to go. Many thanks for that!

Check engine light gone, ESP light gone and a much, much smoother drive. RPM deviation also gone.

However! The vibration/stuttering around 1500 - 2000 RPM persists - I've been advised by some friends that this is a typical bad spark plug indication. I'm having them changed with the next service in a week or two and I'll share the results.

Well, that's a good start.
So what does the new (current) scan reveal?