Using VAG-COM to make sure A4 I just picked up is running right

hutchman

Veteran Member
Joined
Sep 6, 2005
Location
Virginia
TDI
2006 Jetta TDI Pkg 1, 5 Spd, Graphite Blue / 2002 Jetta GLS, Black w/tan leather
I posted some of this information in the General Maint. thread since it half deals with a intake cleaning I did on a A4 I just picked up:
http://forums.tdiclub.com/showthread.php?t=123787

You can see VAG-COM logs of the MAF & Turbo both before and after the intake cleaning.

On WOT, I'm having difficulty feeling the turbo (probably too used to our 06 Jetta). I hear the turbo spin up and the VAG-COM graph looks like the examples on the Ross-Tech TDI page but I don't have a lot of experience with VAG-COM yet so I hope someone here can square me away.

Timing says it is sometimes too advanced too. Not sure if I should be worried about that.

Have not checked IQ yet. I'll do that as soon as I get a chance.

Anything else I should be looking at with VAG-COM to see if everything is in order with this car? I've had it about two weeks now.

Should I disconnect the negative battery cable to reset the computer?

Thanks for any advice/instruction.
 

dieseldorf

Top Post Dawg
Joined
Oct 11, 2000
Location
MA
TDI
ex- 1996 wagon, ex-2000 Jetta
hutchman said:
Timing says it is sometimes too advanced too. Not sure if I should be worried about that.
The car needs to be fully warmed up when checking the timing. You're using the TDi timing checker plug-in, right? It's pretty straightforward. It's ideal to be at the uppermost portion of the graph, IMO.

You can check the MAFS output to ensure that's OK.

You can do the auto-scan routine where it will check all controllers throughout the car.

How many miles on the car? Does it run well? How is fuel economy? hutch, if things seem right, i would not go looking for trouble ;)
 

hutchman

Veteran Member
Joined
Sep 6, 2005
Location
Virginia
TDI
2006 Jetta TDI Pkg 1, 5 Spd, Graphite Blue / 2002 Jetta GLS, Black w/tan leather
Yes, yes, how do I do that? I'm concerned about the VNT vanes maybe being stuck since it wasn't ran at high RPMs from what it appears.


compu_85 said:
You can also put the ECU into basic settings to check the VNT operation. Mine is sticking a bit...

-J
 

hutchman

Veteran Member
Joined
Sep 6, 2005
Location
Virginia
TDI
2006 Jetta TDI Pkg 1, 5 Spd, Graphite Blue / 2002 Jetta GLS, Black w/tan leather
It was cold when I checked the timing and I had just pulled into my driveway from a 200 mile trip when I checked it so if that isn't warmed up enough, I don't know what is! 103 was a high as it got!

I just want to make sure everything is working as it should. Since I think it was babied, I'm concerned there may be some things on it that aren't working right .... namely the turbo. Car was about to turn 69k when I got it.

How do I check the MAF output? Is that any different than the log of the MAF I posted in the General Maint. thread???

I did the auto scan and no faults were found. I'm wondering though since I cleaned the intake & snow screen if I should somehow reset the ECU so it re-learns since it can now get air.

Will the "every once in a while" blip into the "timing too advanced" range hurt anything?

dieseldorf said:
The car needs to be fully warmed up when checking the timing. You're using the TDi timing checker plug-in, right? It's pretty straightforward. It's ideal to be at the uppermost portion of the graph, IMO.

You can check the MAFS output to ensure that's OK.

You can do the auto-scan routine where it will check all controllers throughout the car.

How many miles on the car? Does it run well? How is fuel economy? hutch, if things seem right, i would not go looking for trouble ;)
 

dieseldorf

Top Post Dawg
Joined
Oct 11, 2000
Location
MA
TDI
ex- 1996 wagon, ex-2000 Jetta
Ugh, loads of questions.

How much of a fuel economy increase have you measured since switching to uber-Oel? ...that's what I need to know.
 

hutchman

Veteran Member
Joined
Sep 6, 2005
Location
Virginia
TDI
2006 Jetta TDI Pkg 1, 5 Spd, Graphite Blue / 2002 Jetta GLS, Black w/tan leather
dieseldorf said:
Ugh, loads of questions.

How much of a fuel economy increase have you measured since switching to uber-Oel? ...that's what I need to know.
Sorry ... I have an inquiring mind.

I've been seeing 41-45 MPG with it using D2 so far by the way. I put B20 in it the last full take after I cleaned the intake and it looks like it is still in the range I got before.
 

hutchman

Veteran Member
Joined
Sep 6, 2005
Location
Virginia
TDI
2006 Jetta TDI Pkg 1, 5 Spd, Graphite Blue / 2002 Jetta GLS, Black w/tan leather
compu_85 said:
Excellent! I've been in Group 11 logging the turbo info I posted in the General Maint. thread. I didn't know about watching the back of the turbo. I'll have to check that out.

This leads me to more questions thought ... so this movement is what makes the vanes move??? How would I know if the vanes are getting stuck some? Would it move more in one direction and not as much in the other?

This is good info. I'll try it and report back what I find.

If my vanes were sticking, wouldn't the turbo graph I posted in the other thread show a flat spot or something not being right?

The car drives great, it was taken really good care of ... just babied. Acceleration feels smooth but I just don't feel any boost from the turbo. Like I said, I may be biased by how the A5 feels.
 

dieseldorf

Top Post Dawg
Joined
Oct 11, 2000
Location
MA
TDI
ex- 1996 wagon, ex-2000 Jetta
hutch, one of the guys up in Ca has been able to source the VNT actuator should you need a new one.

Also, you're the 1st person to report no change in fuel economy when switching to 506.01.
 

hutchman

Veteran Member
Joined
Sep 6, 2005
Location
Virginia
TDI
2006 Jetta TDI Pkg 1, 5 Spd, Graphite Blue / 2002 Jetta GLS, Black w/tan leather
dieseldorf said:
hutch, one of the guys up in Ca has been able to source the VNT actuator should you need a new one.

Also, you're the 1st person to report no change in fuel economy when switching to 506.01.
Cool! Thanks for the info. Been reading the .pdf on tearing down the turbo to clean it just to learn more how it works ...

When did I say that about the 506.01? The A5 has the 506.01 and the highest I've seen in it is 47 MPG. Been driving the A5 hard and haven't really been driving for fuel economy ... has almost 9k miles on it now. My wife drives the A5 mostly now and does quite a few 8 mile short trips (kids to school). That combined with reving it beyond 3k during shifts doesn't equal exactly great fuel economy no matter what oil you are using ;)

I haven't had the A4 long enough to get good MPG data on. Only three tanks put through it so far. I dumped the Shell Rotella T for the 507.00 that I'll do a UOA on for SUNRG.

One full take on the clogged intake/snow screen got about 45 and the second tank was in the middle of the intake cleaning. I just put B20 in it today.

Back on the topic, I may be paranoid but I just don't feel any boost on the A4 even though the VAG-COM graph shows it is doing something and looks about right. It is like just a regular car. It has power ... I can pull Sandstone Mountain on I-77 in WV in 5th with cruise on and never have to downshift so that is saying something. I just feel like something isn't quite right but it might just be me. Maybe some PP520's will pep it up a notch!

I'm just trying to learn more (and have fun while doing it) from all you great minds out there! I need to read some more in my Bentley manual to see what other golden nuggets of info I can distil with VAG-COM.
 
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