[amartya_bhp]

I have been a proud owner of an Audi A4 PP+variant since Sep 2022 - a brand new car in Terra Grey Exterior and Beige interior. I have been loving this experience since I parted with my Vento TSi which served me well for about 65000 km and 6 yrs (had bought it new in 2016). Even I have got some mods done by BHPian Agam Bhandari and he helped me get rid of the speed chimes, turned on needle sweep and rear light DRLs. I have already traveled with this GEM of a machine to Kolkata, Vadodara and have already clocked about 8000 km since my purchase and loved the drives (experiences are upcoming soon in a future post, so stay tuned, please)

Off late though, my steed is in the garage with a strange fault that is still undiagnosed by Audi (they are trying various things) and that is why I am putting this up here for your comments/feedback/suggestions. Hopefully, the experience in this forum will help in getting the problem resolved. So, here goes:

The problem shows up during COLD START ONLY in the morning as of now(first observed on Nov 20). Note that I have always used XP95 fuel since Day 1.

1. The first issue is of the engine malfunction indicator light (MIL) flashing and the car slightly shaking at the same time - had already visited the Service Center once on this issue the day on Nov 21, when some tests were run and faults were cleared by SA (Scanning showed random/sporadic cylinder misfire P0300 CODE - was advised that this is a random error and there should not be any issues)
2. The issue was not resolved and the fault continued to show with considerable water coming out of the exhaust at the same time next morning onwards (note the AUTO START STOP function does not work even after the flashing stops and I start to drive)
3. The above problems showed up every time at cold start till the Service Center picked up the car on Nov 28th afternoon.
4. However, on Nov 28th, the drivetrain fault showed up on the MID and the car refused to start in the morning; after three tries, it did start but the same MIL light was flashing with water coming out of the exhaust.

As usual, service center guys at Audi Gurugram, first said that there are fuel contaminants, so they drained the fuel, cleaned the tank and changed related O-rings. But still the problem persists and the car is still with the workshop. They say that they have done engine endoscopy, compression tests and all related tests and the engine is fine. They have then tested the fuel pressure and are currently waiting for feedback from Audi India Technical Team for the way forward.

You can see the related videos at the following links:

1.

http://youtu.be/u6z2vQRPXAg

2.

http://youtu.be/1I8532Q2EiY

This is really not expected in a 40L+ car, and my experience has been dampened a bit, any suggestions to resolve this or what could be the issue would be appreciated.

[ajmat]

Sounds like a coil pack misfire but this would have been picked up by the VCDS. Did the workshop share the error codes that were logged?

[amartya_bhp]

Originally Posted by ajmat

Sounds like a coil pack misfire but this would have been picked up by the VCDS. Did the workshop share the error codes that were logged?

Yes, they were of P0300 type, Random/Sporadic cylinder misfire and they said some fuel issues, did not share the code for the latter, though

[ajmat]

Originally Posted by amartya_bhp

Yes, they were of P0300 type, Random/Sporadic cylinder misfire and they said some fuel issues, did not share the code for the latter, though

So it’s a misfire due to one or more of following

Fuel - Fill up with good quality fuel. It could also be a fuel filter block
Coil pack - check connections , I have forgotten whether VCDS tells you the exact cylinder, if it does, try rotating the coil packs to see if the problem is that
Cylinder head- Check coolant for contamination
Injector Malfunctioning
Duff sparkplug

My bet is that it is a coil pack. Had a similar issue with my vRS

[reppy]

Misfires can also be due to faulty or low fuel pump pressure. Have they checked the fuel pump?

[manson]

In 20000 Kms with my 2021 A4 I've experienced jerky power delivery on one instance when I tanked up from a dodgy petrol pump. It did go away immediately with the next tankful though following which I've almost always stuck to COCO bunks ever since.

As Ajmat suggested its mostly the coil pack, plugs or fuel pump. I've had my Fireblade sound like a Bullet in the past and it was diagnosed to a bad coil.

Regarding the Auto On/Off: Can you check if it hasn't been disabled out of habit when you disconnected the speed warning chimes. Both of these are two or the first features to be disabled by most folks.

[shankar.balan]

Originally Posted by ajmat

So it’s a misfire due to one or more of following

Fuel - Fill up with good quality fuel. It could also be a fuel filter block
Coil pack - check connections , I have forgotten whether VCDS tells you the exact cylinder, if it does, try rotating the coil packs to see if the problem is that
Cylinder head- Check coolant for contamination
Injector Malfunctioning
Duff sparkplug

My bet is that it is a coil pack. Had a similar issue with my vRS

Absolutely right Ajmat. This is the same diagnosis that you had helped me with in May 2021 to identify the Cylinder 3 Combustion Misfire and Emission system malfunction issue in my Cooper which made it go into limp mode. The OBD scanner indicated what was happening and the cylinder as well.
Truly a friend in need is a friend indeed.

Then once the horrible lockdown ended, I swapped coils basis your advice and then it showed Combustion misfire in the cylinder to which I had swapped the coil.

Which is what then immediately prompted me to change all 4 coils to high performance ones and all 4 spark plugs to iridium ones.

And of course the Fuel filter which was desperately ill with grime and sludge and muck.

This adulterated petrol that we get in India is a real menace. Especially in these slightly out of the way semi rural and rural areas.

Best not to be indiscriminate in choosing pumps to fill petrol at. Good idea to prefer IOCL XP95 - solid advice from our fellow member and my other good friend-in-need RobiMahanta. And to be doubly sure of the Octane ratings I use those additives STP or Proctane EVO.

[FAIAAA]

Hi, maybe this has been answered earlier/ elsewhere on the forum - Given that poor / inconsistent fuel quality is a reality in our country, how is it that this problem is mostly seen on German cars while not experienced at all Or little on Japanese cars? Has it got to with quality of fuel pumps / systems on these cars? Shouldn't homologation take care of it especially on CKD/ made in India models of these cars?

[vaibhavyagnik]

Notice that the Gear indicated was D1 then D and then P when drive train malfunction came up. It may the problem with the gear selector sensor switch. It is a common problem with all volkswagens. If the car senses that you are no in "P" it even wont let you start. This is part number required to replace the faulty switch on volkswagen jetta and skoda octavia. So it might be applicable to you too 5Q0713128A
Regarding the engine warning lights, definetly seems like a problem with adulterated fuel.

[amartya_bhp]

Thanks to all for offering your suggestions/possible issues. My main concern is why is it happening only in the first start of the morning? Once the car starts and runs for some time, it is as if there is no problem. Only the AUTO START/STOP does not work, for the first couple of hours. After that, if I restart, NO issues whatsoever with anything! Quite baffling to me and the ASC.

Originally Posted by ajmat

So it’s a misfire due to one or more of following

Fuel - Fill up with good quality fuel. It could also be a fuel filter block
Coil pack - check connections , I have forgotten whether VCDS tells you the exact cylinder, if it does, try rotating the coil packs to see if the problem is that
Cylinder head- Check coolant for contamination
Injector Malfunctioning
Duff sparkplug

My bet is that it is a coil pack. Had a similar issue with my vRS

It is a brand new car, only purchased in Sep 2022 and has run only 8000 km. VCDS scan shows random misfires and ASC says it has run all engine diagnostics, checked and swapped spark plugs and they are fine. So, they suspect it is a fuel delivery/octane issue.

Originally Posted by reppy

Misfires can also be due to faulty or low fuel pump pressure. Have they checked the fuel pump?

That is what they are checking now, and will revert back with the response of Audi India TT.

Originally Posted by manson

In 20000 Kms with my 2021 A4 I've experienced jerky power delivery on one instance when I tanked up from a dodgy petrol pump. It did go away immediately with the next tankful though following which I've almost always stuck to COCO bunks ever since.

As Ajmat suggested its mostly the coil pack, plugs or fuel pump. I've had my Fireblade sound like a Bullet in the past and it was diagnosed to a bad coil.

Regarding the Auto On/Off: Can you check if it hasn't been disabled out of habit when you disconnected the speed warning chimes. Both of these are two or the first features to be disabled by most folks.

Auto ON/OFF does not work when the misfire happens and the CEL/MIL flashes. In that start, it doesn't matter if the flashes stop, and the car runs fine, it will not work. If I again start the car, after say a 20-25 km run, everything is normal and the car behaves as it should with Auto On/Off also working as it should. As I said, this only happens in the first start of the day and started once outside temps started falling due to winter in Delhi.

In fact, there is a TSB by A of A where this issue is reported when outside temps go very high, which is kind of the reverse scenario. There they needed to change the fuel pump.

Originally Posted by shankar.balan

Absolutely right Ajmat. This is the same diagnosis that you had helped me with in May 2021 to identify the Cylinder 3 Combustion Misfire and Emission system malfunction issue in my Cooper which made it go into limp mode. The OBD scanner indicated what was happening and the cylinder as well.
Truly a friend in need is a friend indeed.

Then once the horrible lockdown ended, I swapped coils basis your advice and then it showed Combustion misfire in the cylinder to which I had swapped the coil.

Which is what then immediately prompted me to change all 4 coils to high performance ones and all 4 spark plugs to iridium ones.

And of course the Fuel filter which was desperately ill with grime and sludge and muck.

This adulterated petrol that we get in India is a real menace. Especially in these slightly out of the way semi rural and rural areas.

Best not to be indiscriminate in choosing pumps to fill petrol at. Good idea to prefer IOCL XP95 - solid advice from our fellow member and my other good friend-in-need RobiMahanta. And to be doubly sure of the Octane ratings I use those additives STP or Proctane EVO.

Yes, I have also been filling XP95 from reputed petrol pumps in Delhi NCR, it is a new car, even then they cleaned everything and still the problem persists!

[reppy]

Originally Posted by amartya_bhp

That is what they are checking now, and will revert back with the response of Audi India TT.

Fuel pump issues and low fuel pressure can cause all of the symptoms you mentioned: unburnt fuel from tail pipes during startup, shuddering due to unburnt fuel in that particular cylinder (they should look at misfiring spark plugs too), loss of rpm on giving acceleration etc.

Hopefully should get sorted - ideally they should replace the entire fuel pump assembly and plugs and ask you for feedback after 1000kms. You should escalate with Audi India if the dealer beats around the bush.

[TorqMaster]

If its happening first thing in the morning or first thing after a cold start up check if your fuel cap is properly sealed and shut. Perhaps this could be causing a change in pressure with the fuel pump.

I have seen this similar thing happen in my 3.5 L V6 car and after changing coils, spark plugs and bunch of other stuff it was narrowed down to the fuel cap seal worn out and hence the change in pressure.

Wont hurt to check and cross this off your list.

[amartya_bhp]

Originally Posted by reppy

Fuel pump issues and low fuel pressure can cause all of the symptoms you mentioned: unburnt fuel from tail pipes during startup, shuddering due to unburnt fuel in that particular cylinder (they should look at misfiring spark plugs too), loss of rpm on giving acceleration etc.

Hopefully should get sorted - ideally they should replace the entire fuel pump assembly and plugs and ask you for feedback after 1000kms. You should escalate with Audi India if the dealer beats around the bush.

They are changing the coils and spark plugs after Audi India Technical Diagnosis, lets hope this fixes this.

Originally Posted by TorqMaster

If its happening first thing in the morning or first thing after a cold start up check if your fuel cap is properly sealed and shut. Perhaps this could be causing a change in pressure with the fuel pump.

I have seen this similar thing happen in my 3.5 L V6 car and after changing coils, spark plugs and bunch of other stuff it was narrowed down to the fuel cap seal worn out and hence the change in pressure.

Wont hurt to check and cross this off your list.

Thanks, already had checked that. the fuel cap seal is fine.

[veedub89]

So much water out of the exhaust is astonishing!

Who washes your car? Hired a chap?
Is he taking the garden hose at full pressure and shoving water inside the exhaust to clean it?

Water is seen coming out from the exhaust almost always after a good wash. But so much water makes no sense. Ties in with your other observation that all this happens in the morning only. Because after all the water has come out, there is nothing fouling with the car and it's internals.

[ajs85]

Originally Posted by amartya_bhp

They are changing the coils and spark plugs after Audi India Technical Diagnosis, lets hope this fixes this.



Thanks, already had checked that. the fuel cap seal is fine.

Lately, I'm also facing a somewhat similar issue, with hard acceleration and kick down the car giving a hard jolt. The diagnostic error shows a misfire in cylinder 2, this started after I got the spark plugs and coil changed. Tried swapping coils but still had the same issue. The fuel always used is RON 95 and try to stick to only a few of the marked COCO bunks in Delhi NCR.

Done so far:

• Checked and changed Coils and spark plugs
• Checked pressure of fuel pump via diagnostic readings
• Checked mounts (just in case to rule out any broken mounts)
• Checked and got fuel lines and throttle body cleaned

The car is C200, W204, 2014 with 55k on the clock. Would surely like to get feedback on what AUDI diagnosed with your car. The guys at Mercedes are asking me to now change the fuel pump assembly (both of them are located in the fuel tank)