16 FSI misfire and something I have noticed

[Bumblebee]

Well chaps It failed...... But there are some positives......

I learned that the garage tested it with an MOT garage literally around the corner so it went ripping down the road first, and sure enough the light popped on However the emissions were really good miles inside the max levels, even without an oil change.

I do need some bushes, that I didn't spot but at least I know what they are to do now. How big a job are they? I have pullers and all that kit so curious on bits and complexity. I dont have a press so that may be a factor?

All the new struts, mounts, springs and discs, pads etc all passed, and the garage said its a very clean and tidy example of an A2, which is worth something.

It could have been a lot worse as its not been driven for 18 months that I know of and sat outside in the weather.

 

[Bumblebee]

This is how she looked last night before the big MOT panic checking lights, brakes, wipers, horn, belts etc, etc

 

[PlasticMac]

Fingers crossed it passes, and then go for the sort of drive an FSI was made for
Mac.

The extra wire may be the one that's for the wiper motor, here's the pics.
I'm sure someone will explain the extra earth point, behind the head light, I think. Once I know, I'll add that to mine.
Mac.

 

[dj_efk]

If there's no vcds errors relating to the inlet manifold flaps etc, why think it has problems?
What make are the coil packs?
Mac.

Just from the mileage and the knowledge it has been run for a while on lower additive, lower octane fuel Mac. You'd have to agree it's likely there's some gunk in there that won't be helping.

 

[PlasticMac]

Just from the mileage and the knowledge it has been run for a while on lower additive, lower octane fuel Mac. You'd have to agree it's likely there's some gunk in there that won't be helping.

You're right, it won't be clean in there, but with no flap related errors, the flaps are moving correctly, so I think it's unlikely that the cause of the misfire is inlet related, especially as it's just cylinder 2.
Having been unused for ages, dodgy electrical connectors, earth points etc, are prime candidates for the misfire.
If not tried already, swap coil pack 2 with one of the others, even Bosch can fail.
My hesitance over the inlet manifold is that in doing that job, which entails removing lots of parts to get at the manifold, the risk of "collateral damage" is high.
If the misfire can be sorted, then @Bumblebee can get some lively miles in, and then prioritise what needs doing.
I like to find the fault, but if you do a big strip down, find little, but it's OK after, you will not know what the cause was, and so don't know if it'll return.
Mac.

 

[Bumblebee]

You're right, it won't be clean in there, but with no flap related errors, the flaps are moving correctly, so I think it's unlikely that the cause of the misfire is inlet related, especially as it's just cylinder 2.
Having been unused for ages, dodgy electrical connectors, earth points etc, are prime candidates for the misfire.
If not tried already, swap coil pack 2 with one of the others, even Bosch can fail.
My hesitance over the inlet manifold is that in doing that job, which entails removing lots of parts to get at the manifold, the risk of "collateral damage" is high.
If the misfire can be sorted, then @Bumblebee can get some lively miles in, and then prioritise what needs doing.
I like to find the fault, but if you do a big strip down, find little, but it's OK after, you will not know what the cause was, and so don't know if it'll return.
Mac.

Hi chaps. I've done the coil swaps, as that was checked when I got the car. Also plug changes etc....
I agree that trying to trace a short or something like that when coils are working harder would be sensible.

As it appears to be one cylinder and it raises its head when under load or hard revving I am keen to get to the bottom of this one, without going head first into a strip down on inlet side of things......

It would be fantastic if it's something easier to point the finger at and sort for sure....

Using some rational that if it was purely bad fuel and flaps then it may show in more than one cylinder or is that me being naive

Sent from my ONEPLUS A3003 using Tapatalk

 

[Crgwal]

Sorry are you saying you did a coil swap and it made no difference?

 

[Bumblebee]

Sorry are you saying you did a coil swap and it made no difference?

Yes I am. No difference at all. Sorry if that was as clear as mud.....

 

[Bumblebee]

Just come across an interesting thread on another forum where an A2 1.4 had a constant cylinder 2 misfire issue..... I have noticed that my car starts and runs smooth until it's warmed up a bit etc driven a bit......
Could it be the knock sensor on BAD engine???

Reading the posts there is many similarities in how the car works pre EML on and codes cleared returns to normal until EML comes on again.

Where is knock sensor and how can you test it????

[1.4 AUA] Electrical problem injection/ignition: Help please from France

Dear German A2 friends, This is my first posting here, as Bret recommended I ask your advice. I have a long ongoing problem with my A2 1.4 petrol. I would be most grateful if you could give me some advice. Below is my last post on the A2OC website on the subject: My Audi A2 has now been with my l...

a2-freun.de

 

[Crgwal]

Hi,

The FSI is a hard car to diagnose without some real experience. You can very easily go down the rabbit whole and start guessing lots of things.

In my first post I explained that I had the same symptoms as your car.

The uneven reving part that you have explained when the engine is hot. I believe this is not related to your misfire. Rather an airleak in the vacuum system.

I would expect it will be harder work to get rid of the missfire.

I would focus on this bouncing rev pattern at hot temperatures.

How obvious is the bouncing rev when the car is hot?

 

[Bumblebee]

Hi,

The FSI is a hard car to diagnose without some real experience. You can very easily go down the rabbit whole and start guessing lots of things.

In my first post I explained that I had the same symptoms as your car.

The uneven reving part that you have explained when the engine is hot. I believe this is not related to your misfire. Rather an airleak in the vacuum system.

I would expect it will be harder work to get rid of the missfire.

I would focus on this bouncing rev pattern at hot temperatures.

How obvious is the bouncing rev when the car is hot?

Negligible to be honest. Probably jumps a bit by about 50-100 rpm....... I've seen some that really go up and down

 

[PlasticMac]

Just come across an interesting thread on another forum where an A2 1.4 had a constant cylinder 2 misfire issue..... I have noticed that my car starts and runs smooth until it's warmed up a bit etc driven a bit......
Could it be the knock sensor on BAD engine???

Reading the posts there is many similarities in how the car works pre EML on and codes cleared returns to normal until EML comes on again.

Where is knock sensor and how can you test it????

[1.4 AUA] Electrical problem injection/ignition: Help please from France

Dear German A2 friends, This is my first posting here, as Bret recommended I ask your advice. I have a long ongoing problem with my A2 1.4 petrol. I would be most grateful if you could give me some advice. Below is my last post on the A2OC website on the subject: My Audi A2 has now been with my l...

a2-freun.de

I'd expect the knock sensor not to be cylinder specific, but, it would have had a hard life on 95 octane.
Do you feel the misfire, or, is it just the MIL & error code?
Mac.

 

[Bumblebee]

I'd expect the knock sensor not to be cylinder specific, but, it would have had a hard life on 95 octane.
Do you feel the misfire, or, is it just the MIL & error code?
Mac.

Mac

When the EML comes on it definitely gets a bit more lumpy for sure and works harder to pull, like a slight loss of power..... It starts initially with a flashing EML and then goes off, after it does this a couple of times normal driving through gears one revs get above about 3,000rpm it then comes on and stays on a feels less powerful.....lumpy running. Stop car clear codes and back to normal.....

 

[PlasticMac]

I'd expect the knock sensor not to be cylinder specific, but, it would have had a hard life on 95 octane.
Do you feel the misfire, or, is it just the MIL & error code?
Mac.

Injector swap perhao

Mac

When the EML comes on it definitely gets a bit more lumpy for sure and works harder to pull, like a slight loss of power..... It starts initially with a flashing EML and then goes off, after it does this a couple of times normal driving through gears one revs get above about 3,000rpm it then comes on and stays on a feels less powerful.....lumpy running. Stop car clear codes and back to normal.....

Sticking with the cylinder two misfire, swap injector two and one of the others perhaps.
Mac.

 

[Evripidis]

Might as well clean the back of the valves and get a new/brand new second hand injector or maybe even a full set.

I cannot fathom the thought of having to pull everything out twice for fixing just one problem. I've taken this process down to fine art now and I cannot still think of having to do it twice.

Also replace the plastic coolant pipe and clean the oil separator while you are at it if you haven't already done so. Also a good time to replace the vaccum hoses on the inlet plenum.

As fas as the air leaks on the sump, etc. Just use black rtv rather than trying to source already ageing parts and funny-sized o-rings. I find the dipstick tubes leak the easiest whereas the fillers not so much.

Apologies if this sounds overwhelming, but this is what I would have done, had I known any better.

 

[Bumblebee]

Injector swap perhao

Sticking with the cylinder two misfire, swap injector two and one of the others perhaps.
Mac.

Isn't that a lot of work swapping injectors and taking down inlet side???

 

[Bumblebee]

Might as well clean the back of the valves and get a new/brand new second hand injector.......
Apologies if this sounds overwhelming, but this is what I would have done, had I known any better.

I've got a good used and tested injector because po told me an auto electrician couldn't find anything else when this first raised its head before it was offered to me for washers. Always loved this car so as we worked together I couldn't say no....
As it was well serviced and cared for apart from cheaper fuel, she did use it daily and it did enough miles commuting from Worcester to Tewkesbury each day to get warm etc doing miles at decent speeds etc....
I guess I am hoping it's something less evasive than changing injectors and tearing down inlet manifold...

 

[Crgwal]

Some more interesting information. My FSI is at 135k miles. I had flashing EML and missfires before I replaced my injectors.

The flashing EML usually started from having my car in idle for a length of time.

I think you are at 110k? I would only think this has do be done sooner or later.

Keep at it!

 

[Bumblebee]

Some more interesting information. My FSI is at 135k miles. I had flashing EML and missfires before I replaced my injectors.

The flashing EML usually started from having my car in idle for a length of time.

I think you are at 110k? I would only think this has do be done sooner or later.

Keep at it!

I never get flashing EML at idle mate...can idle until fan kicks in from cold

 

[Crgwal]

You get a flashing EML at the start? I took that as idle sorry buddy.

I'm not sure what you know or not and I am no expert. A flashing EML is when it's time to stop running the car and/or there is an emediate problem. A larger fail in the engine than a fully lit EML.

My guess is the injectors but we can never no for sure.

Good luck. I hope you get to the bottom of it. Keep us updated.