Help needed!..3.2Q DSG Hesitant engine ~ 2k rpm

well i have had a mess about this morning, and to be honest I havent a clue what i am looking re teh lambda probes, but I am in agreement with paddy, the two sensors agree with each other more or less. bank 1 seemed to have ever so slightly less voltage then the 2. but like .1 of a volt of something.

Did notice this though -
voltage.jpg


knock voltage. Notice how it says a max of 2 volts! and this was at 1920rpm.

would love to see what other people are getting, and also a known good car.

that cant be right. and it makes sense if the knock sensors are kicking in and killing the ignition
 
Paddy, try logging the values of the post cat lambdas (block 36) with the car parked. I've done it both ways and while moving the values are almost identical, but while parked are very different. I logged my mates this morning while parked and his are identical! They should read around 0.6/0.7 at 1800rpm 'ish but bank 1 on mine reads only 0.1/0.2. indicating a weak mixture.
I have all the data in an excel spredsheet format if I can work out how to post it as a table!
Following on from another recent thread HERE I believe my problem IS the exhaust, the only problem is the downpipe and cats etc. retail at £1130
 
audi upgrades
Well i did a knock voltage test and at 2k revs cylinders 1-2-3 are less than 2v and 3-4-5 are up to 4v. I am guessing that the banks are numbered 123 and 456 and not 135 and 246 which means i have a problem on one bank.

I know some systems alter the ignition timing and some the cam timing ?? but not sure about the 3.2. The way to check is to set it up with VCDS on ignition timing block and tap the engine block with a copper mallet and see if the ignition ******* on the VCDS. that will tell if the knock sensor is working as well.

My lambda sensors are all steady at about 0. 5-6 volt which is good. 0.45v is optimal

http://www.picoauto.com/applications/lambda-sensor.html

Can the cam timing be checked on VCDS ??
 
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Right here's my log

LambdaH3LJU.jpg


And here's the one from the other 3.2, forgot to log block 1 though for the rpm reference!

MarcsLambda.jpg



As you can see mine are definately out of spec!
Also I did notice that even though his rev counter was rock solid at any rpm, there is a little popping through the exhaust so a little bit does appear normal
 
So is the knock sensor on bank 1 reading lean as well Ju ?
Also what are the readings like pre cat ? do they back up the post cat readings ?
 
It bothers me that the problems seem to be on banks rather than in general so common components like throttle body's and MAFs ar ruled out. i just hope that this is not pointing back too cam timing again . also seems odd that we all have the same problem but non of us are agreeing on blocks faults...we may be being mislead ?
Poping in the pipe is almost sure to be an air leak somewhere.
 
From the link above. It seems a sensor can get tired witjhout failing completely.


A lambda sensor’s normal life span is 30,000 to 50,000 miles, but the sensor may fail prematurely if it becomes clogged with carbon, or is contaminated by lead from leaded petrol or silicone from an antifreeze leak or from silicone sealer.

As the sensor ages, it becomes sluggish. Eventually it produces an unchanging signal or no signal at all. When this happens, the Check Engine Light may come on, and the engine may experience drivability problems caused by an overly rich fuel condition. Poor fuel economy, elevated CO and HC emissions, poor idle, and/or hesitation during acceleration are typical complaints.

If the average voltage from the lambda sensor is running high (more than 0.50V), it indicates a rich condition, possibly due to a bad MAP, MAF or Air Flow sensor or leaky injector. If the average voltage reading is running low (less than 0.45V), the mixture is running lean possibly due to a vacuum leak or because the sensor itself is bad.

If the lambda sensor continually reads high (rich), it will cause the engine computer to lean out the fuel mixture in an attempt to compensate for the rich reading. This can cause lean misfire, hesitation, stumbling, poor idle and high hydrocarbon emissions (from misfiring).

If the lambda sensor continually reads low (lean), it will cause the engine computer to enrich the fuel mixture. Injector pulse width will increase causing fuel consumption and carbon monoxide emissions to go up. Constant rich fuel mixture can also cause the catalytic converter to overheat and it may be damaged.

If the lambda sensor’s output is sluggish and does not change (low cross counts & long transition times), the engine computer will not be able to maintain a properly balanced fuel mixture. The engine may run too rich or too lean, depending on the operating conditions. This, in turn, may cause drivability problems such as misfiring, surging, poor idle, and high emissions.

If a heated sensor has a faulty heating circuit or element, the sensor can cool off at idle causing the system to go into open loop. This usually results in a fixed, rich fuel mixture that will increase emissions.

Sometimes an apparent lambda sensor problem is not really a faulty sensor. An air leak in the intake or exhaust manifold or even a fouled spark plug, for example, will cause the lambda sensor to give a false lean indication. The sensor reacts only to the presence or absence of oxygen in the exhaust. It has no way of knowing where the extra oxygen came from. So keep that in mind when diagnosing oxygen sensor problems.

The lambda sensor is also grounded through the exhaust manifold. If rust and corrosion of the manifold gaskets and bolts is creating resistance, it may affect the sensor's output. To rule out a bad ground, use a digital volt meter to check for a voltage drop between the sensor shell and the engine block. More than 0.1v can cause a problem.
 
Not too sure on the other readings paddy will have to run them again. But I DEFINATELY have a small leak on my exhaust as I can hear it, even more so now my ears are tuned to it lol!

Looks like we could all be chasing different faults but with the same symptoms after all as mentioned by John in post #501
 
Don't think I have a faulty sensor though as if I log it when driving, the 2 match up fine. I'm assuming the movement of the engine is sealing the leak up
 
Done a quick log with blocks 1,33,36. Looking at the figures in block 33 Bank1 is slightly lower than Bank2 although not by a great amount, how do these compare to yours?

Lambda.jpg
 
sorry ju but the lap top is vista and everything else i have is XP and i cant get the log from vista office to office 2000 XP....lol

All i can say is the readings for bank 1 and 2 pre and post cat are very similar , its my knock sensor readings that are out of range on bank 2. at about 4v instead of 2v max
 
Lol! tell me about it, my heads spinning!!
I use an xp laptop for vcds and had to bluetooth it to my windows 7 lappy and into excel, getting it to a forum post is easy once you realise you can copy and paste into paint!

I'll log the knock sensors tomorrow
 
oh the bit about earthing through the exhaust is interesting?

on my exhuast there was a small metal link onto the gearbox, which had snapped before I got it, I wonder if that is there for earthing reasons????

I always thought it was a bit **** poor as mount, thats why i never bothered to fix it up.
 
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That strap is missing on mine too, used to be there but was never put back on by the Audi dealer that did the chain. Oh and they also left 3 bolts out of the gearbox to the engine!!
I'd say it was just there as a support strap for the downpipe.
 
audi upgrades
whats the point of it though?
I will be making a meaty earth strap for the exhaust tomorrow to see what effect that has

the fact that its bank related, and not individual cylinder related points toward a knackered lambda, or maybe even a blocked cat or something.
 
If they really have a life span of 50k then mine are running out of time ..:)
 
In my case I would say it's a leak after the first lambda on bank 1
 
Just to hijack thread for a min. What type of fuel delivery does our 3.2 have? Parkers list it as direct injection (FSi?) and my logbook shows a CO2 output of 230. Strangely my old 3.2 never had any problems and had an CO2 of 247. Thats also listed as having direct injection.

The strange bit though, the new shape TT, fitted with a 3.2 engine is shown as MPFI, not direct and the CO2 has risen to 247 again? Could this all be an issue to try and meet emissions? One that Audi realised they couldn't solve by leaning of the mixture at 1800rpm and thus reverted back to the previous map?

Just a thought.

Regards

Rob
 
Two things Rob, mine is 04 and 247Co and it does it. and.....its only done it since the day after it long life service 7k miles ago. so it was fine for 35k miles.
It did however have a new lambds sensor fitted at the same time but then it had a permanant light on the dash to say it had gone. I think the lambda's are prob ok and are just picking up a fault elsewhere.
 
One thing i noticed yesterday with VCDS is the lambda heating. It lists bank1 sensor 2 but not bank2 sensor2 and my B1 S2 had the heating on even though it was hot enough for the fan to be running.
 
Ok so here's the result of the ignition voltages

knocksensorlog.jpg


So which is bank 1........... 1-3 or 4-6?
 
What are the Lambda reading there ? Bank 2 is half that of bank 1 ? and i would say your bank 2 ignition voltages were correspondingly up as well.
 
so, either we have a problem with a lambda probe reading incorrectly, or the only other possiblity, if the knock sensors are by bank instead of 1 per cylinder, then we could have a knock sensor misreading. got to be one of the two now.

I am excited about this!
 
We do seem to be getting somewhere with the figures but we now need to understand them.
I've been looking over my figures and the low reading on my post cat Lambda was on bank 1 whereas the voltages on the cylinders are out on bank 2, now this I found confusing. According to a previous post, the black connector is for bank 1 and the brown is bank 2. This I have confirmed by looking at the connectors under the bonnet for the pre cat lambdas. I've also been under the car to check the post cat ones and low and behold the black connector goes to bank 2 and not bank 1! if the colour scheme is carried through then my post cat lambdas are screwed in the opposite way round, I'll have to get back under and disconnect one to check, but if that's the case then all the out of spec data is on bank 2 i.e high voltages on cylinders 4-6 and the very low reading on the post cat lambda. The downpipe on bank 2 is also the one that I noticed the carbonation on the flexi joint as well!

Interesting!
 
What i dont understand is if you have a set of bad figures from a Lambda, why are those figures not acted on with an ignition advance or similar, correcting the figures. In that case the figure should not stay consistently bad. They should be corrected further up the chain....??? to me, the fact that the lambda figure remain bad means that something is not doing its job further up the line.....like a cam not advancing....or ignition not advancing, ie: the lambda sends out a signal but its not being acted on....Does that make sense ?
Also, why does the car not register a fault code if the lambda/knock sensors are out of range ?
 
Paddy, and anyone else with this issue,

Mates car came back from Audi Specialist and Audi Dealer with the following:

Tiny hole in the flexi pipe but specialist claims that the Lambda sensor is before the hole so should not cause this issue. The Now be sure that the car does have the same as you are posing but also sometimes stalls. It idles at between 600 and 640 which is below the man spec. Most of the time it sits at 600 post the choke. Man spec is 650. This may be causing it to stall ? Thats with the air con off !!

So first question and suggestion:

DO all of you that have this issue, also have a small hole in the flexi pipe ? If so have you had it replaced with an Audi or performance version exhaust from the manifold to the end pipe ?

Audi and Specialist have a tech fix for this that requires the inlet manifold seal and injector seals to be replaced. My only concerns with this suggestion is 1) its expensive and 2) the issue is very random and sporadic on the cars. The specialist states they would expect an air leak to cause consistently bad running issues ?

Checkout the strange Lambda values on Bank 1 below. Do you all have this ?

Summary:

Ok, many of us have had lost of kit changed but no one has said if they have had the etch fix I was advised carried out ?

The precise issue it fixes is "Sporadic MAF behaviour" faults in the log. Audi found that when the MAF was replaced and returned to them, most of the suspected faulty MAFs were fine, so they suggested this fix for the inlet manifold seal and injectors.


Does anyone know a good after market exhaust from the Manifold to the end pipe ?

Lambda is all over the shop on this car :crying: on one bank but that may be the hole in the exhaust?

At Idle: Bank 1 is broken. Note sure if this is the flexi pipe tiny hole?

RPM Lambda Bank 1 Lambda Bank 2
600 -0.8 0.8
600 -1.6 0.8
600 0 0.8
640 2.3 0.8
600 2.3 0.8
640 1.6 0.8
640 5.5 0.8
640 8.6 0.8
640 7 0.8
600 6.3 0.8
600 7 0.8
680 7 0.8
640 5.5 0.8
640 0 0.8
600 2.3 0.8
600 6.3 0.9
600 4.7 0.9
 
All my figures are posted above if you want to compare but I've never had any MAF faults and mine runs fine at idle (600 rpm as well). I do have a flexi pipe leak and have looked into front pipe replacement but it's the whole front end that is in one piece i.e downpipes, cats and front silencers! Audi retail this at £1130 ouch! and after much internet searching have found no aftermarket replacement as yet, all the available exhausts start from the middle section back
 
Hi Ju,

Just had confirmation back from Master Tec that range of Lambda is -5 to + 5 to be in spec.

I have a few 7's at only 600rpm which must be out of spec. Worth checking the engine speed when you log Bank 1 and Bank 2 at idle. I noticed somone posted their values and theirs had a few 10.6 in the log; twice what it should be but that was at ober 1000 rpm with part throttle.
 
marmite said:
Hi Ju,

Just had confirmation back from Master Tec that range of Lambda is -5 to + 5 to be in spec.

I have a few 7's at only 600rpm which must be out of spec. Worth checking the engine speed when you log Bank 1 and Bank 2 at idle. I noticed somone posted their values and theirs had a few 10.6 in the log; twice what it should be but that was at ober 1000 rpm with part throttle.
Click to expand...

so your saying the figures should be taken at tick over ? that would explain why some of these readings are so far out but there is no fault code.
 
Going to plug my mates good 3.2 in again tonight, any special requests on what to log?
 
marmite said:
Hi Ju,

Just had confirmation back from Master Tec that range of Lambda is -5 to + 5 to be in spec.

I have a few 7's at only 600rpm which must be out of spec. Worth checking the engine speed when you log Bank 1 and Bank 2 at idle. I noticed somone posted their values and theirs had a few 10.6 in the log; twice what it should be but that was at ober 1000 rpm with part throttle.
Click to expand...

It is interesting that the figures are out of spec and will no doubt point to the cause, but it's still all double dutch to me lol!

Mine runs more or less sweet as a nut and sits solid at 600rpm, it just won't hold constant revs at 1400-2000rpm while parked. On the road though it pulls as smooth as you like at the moment.

Are we all having problems with Bank 2 then?
 
bank 2 for me, I have a consistent difference in the cat temps on bank 1 to 2 so you can check that.

the main one for me is to check channels 26 and 27 which are the cylinder knock voltages. 1, 2, and 3 were low and within spec (below 2v) where as 5 6 and 7 are well over.

One thing to note which I forgot to mention, I fitted a big earth strap on the exhaust where that crap effort from audi had snapped, and all today the car has behaved impeccably. its got a much smoother pick from 1500rpm right the way through now. All the other vag com readings appear to be unchanged tho particularly the knock sensor voltages, so its not fixed, but its certainly a lot smoother!
The car was actually enjoyable to drive for the first time in ages today - fuel economy was shocking though lol
 
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does anyone else get the error 18025 - Glow Plug Pre-Heat Indicator (K29): Open or Short to Ground
> P1617 - 001 - Upper Limit Exceeded - Intermittent
I asked VCDS about it and got this reply

Paddy,

Thanks for registering. That certainly does seem like a curious fault
for a gasser to be throwing. Does it possibly have a performance chip?
There could be a error in the ECU that causes it to report an
implausible fault.

Regards,
Andy
--------------------------------

could we have a ECU fault ??
 
Right took these readings tonight, the car is a 54 plate with 27k on the clock and runs perfect.

Marcscylindervoltages.jpg


Marcscatalysttemps.jpg


marcscamshaftadjustment.jpg
 
Anything interesting Julian? Reading it on I phone isn't so easy!
 
Coxylaad said:
bank 2 for me, I have a consistent difference in the cat temps on bank 1 to 2 so you can check that.

the main one for me is to check channels 26 and 27 which are the cylinder knock voltages. 1, 2, and 3 were low and within spec (below 2v) where as 5 6 and 7 are well over.

One thing to note which I forgot to mention, I fitted a big earth strap on the exhaust where that crap effort from audi had snapped, and all today the car has behaved impeccably. its got a much smoother pick from 1500rpm right the way through now. All the other vag com readings appear to be unchanged tho particularly the knock sensor voltages, so its not fixed, but its certainly a lot smoother!
The car was actually enjoyable to drive for the first time in ages today - fuel economy was shocking though lol
Click to expand...

Well that may explain why the heavy rain and flooding two weeks ago caused the car to become very unreliable, stalling and on one occasion an ECU dash light. Work was done to replace some earths under the bonnet but that did not help.

Can you let me know where that exhaust earth is please ? Even better, if you can do you have a photo of it ? I think its time that gets done, but I'll wait to hear back from you as no Master Tec seems to have noticed it. Then again, tow of them did not even notice the hole in the flexi pipe !!

Thanks
 
its directly below the throttle body attaching to the engine block just above the gearbox.

****** it seems the good cars show the same cylinder volage difference between the 2 banks.

truthfully since fitting that earth strap my car now behave impeccably when driving, and thats all i want really.
 
Is that strap visable without taking bits off?
 
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