need help with VCDS codes

need help with VCDS codes SOLVED

need some basic help on what to do next.
symptoms:
much reduced power (especially up an incline)
ALOT of smoke with acceleration
2 Faults Found:
005661 - Glowplug for Cylinder 4 (Q13): Open Circuit
P161D - 000 - -
Freeze Frame:
Fault Status: 01110000
Fault Priority: 0
Fault Frequency: 8
Mileage: 267542 km
Time Indication: 0
Date: 2000.00.00
Time: 00:38:31
Freeze Frame:
RPM: 798 /min
Speed: 0.0 km/h
Load: 0.0 %
Voltage: 14.06 V
Bin. Bits: 00001100
Temperature: 23.4�C
Bin. Bits: 10110000
000257 - Mass Air Flow Sensor (G70): Implausible Signal
P0101 - 000 - -
Freeze Frame:
Fault Status: 01110000
Fault Priority: 0
Fault Frequency: 1
Mileage: 270307 km
Time Indication: 0
Date: 2000.00.00
Time: 23:43:50
Freeze Frame:
RPM: 2310 /min
Speed: 84.0 km/h
Temperature: 27.9�C
Absolute Pres.: 999.6 mbar
Mass Flow: 24.18 g/s
(no units): 2.59
Temperature: 82.8�C
Readiness: 1 2 0 0 0
I am not a mechanic by any means but would like to fix it myself if possible.
any help would be appreciated
Doug

I think the maf one is the one you want to look into, it's the one thing that could cause your problems, try unplugging it and see if there's any improvement. You could also try cleaning it, there's various stuff around here about that but I don't have any pages bookmarked, a search should bring something up though. You could also try testing the maf with vcds/vagcom if you have it.

http://www.myturbodiesel.com/1000q/a4/MAF-sensor-testing-VW-cleaner.htm

reset error codes and....

reset codes and thru CEL again. now only shows glow-plug#4 error again.

using 10.6.0 vcds... don't see MAF under any of my groups. EGR is #3

any suggestions?

I guess putting in a glow-plug is probably a start.

-doug

Dead GP will not affect power or smoke. Worst I ever experienced was having to restart the car once due to a bad GP that did not light one cylinder right away. This time of year, don't think even that would happen.

The MAF can fail gradually and not throw a code, try the unplug and drive diagnostic. Should make ECU use default value and run better if it is dead. Using a stock airfilter? Aftermarket oiled (K&N for one) have been known to kill the MAF sensor in short order.

MAF sensor data can be found in Group 10, field 1 in VCDS.

I just noticed that the fault frequency for the MAF code is only 1. This may indicate that it is not so likely the problem (but don't rule it out either). Based on your symptoms I would pull the EGR valve and make sure it is closing completely. Would also consider pulling the valve cover and taking a peak at the cam.

I would say to check your turbo actuator in Basic Settings group 11 to make sure it is moving freely across the whole range, but I think you would have seen a boost pressure regulation code if that were the issue.

Dumb question: have you checked your airfilter? Gotten a new fuel filter in there anytime recently?

no stupid questions here

replaced fuel filter after first CEL and air-filter is fairly new andnot oiled-type looks pretty stock...

I will post some EGR data and try to find MAF blocks.

Thanks-

doug

Group 10 field 1 for MAF.

Also want to add that I have read of throttle valve (mounted to EGR/intake manifold) have been known to fail. On our cars that valve is more than just anti-shudder on shutdown, it is also used by the EGR system.

The throttle valve can block airflow and the EGR can leak boost pressure, either will cause your issue.

Sent from my POSberry using Tapatalk

drove with MAF unplugged and it drove basically the same.

the spec/actual values of the EGR are very similar even with high revs.

the MAF actual never really gets over 300 - not good right?

air-filter was a little dirty on end close to intake... flipped it 180 but no difference noted.

what you think?

-doug

MAF not reading higher than 300 is definitely not good. It should be getting to around 1000 (give or take)at WOT.

It may be simple as a MAF sensor failure. But it might be a restriction in the intake path after the turbo too, actually limiting flow.

I would think a stuck (failed) throttle valve could do that if it failed just slightly open. IIRC that valve should default to full open if it is OK. You might unplug it (it is what the soft intake hose plugs into on the intake manifold assy) and drive it again and see if power returns. If it doesn't I would pop the hose off and see if it is full open. IIRC it should cycle fully with key on to check it. If no change and it is in fact open then MAF failure is likely.

I doubt a failed cam could be choking the engine enough to limit MAF to 300, nor would a boost leak or malfunctioning turbo/actuator. Though if it were me I would graph group 11 while driving to see if boost actual is following requested before I replaced the MAF. It would be good to know the car is not in perpetual limp mode causing low boost request.

Sent from my POSberry using Tapatalk

throttle valve looks good. seems well actuated. open /close cycles with key on/off.
here is graph of 0 --> ~50 mph 1 --> 4 th gears group ll
http://farm7.static.flickr.com/6162/6166992685_53c1dc73f5_z.jpg
what does it mean? no clue here

Internet diagnosis is not preferred. But, based one what you have posted and checked, I would say a failed MAF sensor is the most likely cause of your low power issue.

I recently had mine fail at 207K miles and it passed all the diagnostics I could find here, but it was the cause of my low boost/power issue. Don't know how many miles on your car but at 6 years old, it has likely done pretty well to last this long.

Member DanG144 is extremely sharp with this sort of stuff. If you want a good second opinion before buying parts you could PM him asking to review this thread. He might see something I have missed.

On the glow plug, they fail. You can verify that it is the plug by using a mutimeter to check resistance between the contact on the end of the plug and the block. Just unclip the harness from all 4 and you can check it in place. If it is dead it will be open. Number 4 is the one closest to the drivers side. I keep a spare or two in my garage.

Good luck.

ping'd danG like you suggested - thanks for your time and help. much appreciated- doug

Doug,
Perhaps you could do a pull from 2000 rpm in 3rd gear to 4500 rpm, then shift to 4th and pull again, logging the data from groups 3 and 11 to a .csv file? Have the throttle to the floor or none - no partial throttle. Group 003 says it is EGR, but it is really the reading from the MAF sensor. When you go to full throttle the EGR should close and you should get over 850 mg/stroke of air from the MAF. When you unplug the MAF then it should insert a value of 550 mg per stroke or so, and give you about 60% power with no smoke. So the MAF seems doubtful as the culprit.

It is hard to tell what is going on from the data presented. You are 2.5 hours away, any chance you could come to my place Friday, Saturday or Sunday?

One potential issue is the turbo actuator vane stop setting. Another is the cam, then the EGR and MAF sensor as already mentioned. If it is the cam, then driving it is a bad idea - the other failures - it will not hurt to drive it.

dan, did a round trip to chicago in late august/ that is when problems with power became VERY evident. could not climb the hills in NC without down shifting ALOT. hope i did not toast my engine (if it is the cam). i have this week off so i could bring car down to you. i will try to do the logging suggested and post for you to see. -tia -doug

Doug,
I just got volunteered to do something on Friday, so that day is up in the air.
Dan

lil-smokie

car would not quite get to 4500 in 3rd gear ... topped out at about 4200. alot of smoke... expecting a call from EPA .
here is link to csv file on dropbox
http://db.tt/vHzF6lp
let me know about friday or sat-
thanks -doug

edit: first file looks clipped maybe this one is better:

http://db.tt/2yvo5cbt

also thru these fault codes (CEL were cleared ... I think)

http://db.tt/4AOXMXna

I am yielding to Dan's greater knowledge on this one. I will be following it though, just for my edification.

That log is throttle off, coasting for a very short time. Seems like a log also needs done at 2-4K WOT (full throttle) in 3rd or 4th too to learn much. *above post was edited while I was posting to show whole log. Still it is at part throttle and would think FULL throttle log is still in order*

Dan mentioned a VNT stop screw setting issue, which I think I am seeing in the previously posted log. However, that should result in a boost spike that could also show as a hesitation to the driver, but should not create that high amount of smoke or the very low MAF value. An EGR issue could cause extreme smoke and low power from what would essentially be a boost leak, but again - the low MAF value?

The cam issue seems like it would have to get really really bad to cause these levels of running problems. I doubt the cam is fully OK considering it is a BRM of that age, but I hope it did not get bad enough to choke the motor enough to limit MAF that much. Seems like you would be looking at multiple 'holed' cam followers and possible major head work ($$$) . If it could be that bad, I would be looking under the valve cover ASAP.

Again, not trying to confuse the effort - just interested . Hope you get it sorted.

fresh (real) data

realized i was hitting (start) to stop the logging process. -oops
here is log file of 3rd and 4th gears from 2k rpms--> to all she has @full throttle.
end of log in 4 gear was up a grade so you can see i could not get any more rpms.
hope this will show something of use.
http://db.tt/dTKSgWwg
-TIA
-doug

Doug,
Are you getting my Private Messages?
Dan

just got back from vw dealer

had them do diagnostics on my engine this morning. they said cam needed to be replaced (no surprise). i could not see the wear myself -maybe because i have never seen a new one. got an estimate for ~2K for cam replace and an additional 800 for TB with the works if done at same time as cam- also said that O2 sensor may need to be replaced -but was not included in price.
I called my new IBF---internet best friend--- danG and he gave me his thoughts on the matter. I am going to drive it to his place tomorrow -open it up and let him take a look see.
I drove it very 'softly' home with no issues... runs like it has for a couple of weeks --got 46+MPG driving home-- not bad for a sick baby

RESOLVED with new cam

Spent the day at DanG's shop and he graciously installed a new cam for me ( I helped a little but I think Dan wanted to finish before 2012 . I was more than just lucky to make it this long with such a 'toasted' cam. Holes/bits of this and that everywhere- It was not good . He put in a BEW cam - did a 30 min break-in. - long story short got me home before 8:30pm.... and i can't remember the car ever running any better. Thankyou Capt.Dan!
Pulled another log of the same tests that Dan originally suggested to compare.
This log is with a really bad cam... if your numbers are better don't think your cam is OK- as mine was really really bad: http://db.tt/dTKSgWwg
And this is after cam replacement: http://db.tt/XvKNVg5b
ps-looks like group 11 did not record. guess I will rerun if anyone is interested.
but group 3 values look much better.