16 FSI misfire and something I have noticed

I know it’s not going to cure a misfire but here’s a tip to keep your FSI running sweet. To prevent the EGR crud bunging up the intake and flaps you can disconnect it at the exhaust manifold and blank the manifold. Just put a little filter on the EGR pipe, the system does not know if it is passing recirculated gas or fresh air….
 
PlasticMac said:
Sorry, didn't realise injectors are a manifold off job.
Check connections at ECU, as that's the point where the electrics become cylinder specific.
Mac.
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Thanks Mac. Does you know the colour of wire for cylinder no2?
Also I believe the ECU is underneath to black box you first see in passenger footwell?

TIA

Wayne
 
Bumblebee said:
That would be wonderful and thank you, as always.... 👍
Click to expand...
Screenshot 2022-10-17 10.56.13.png


This gives wire colours and pin outs. (Cheers to @Andrew for the schematic a while back)
Mac.
 
dj_efk said:
If the lower manifold has never been off, then from what I understand from others' experience here, nothing beats taking it off and cleaning it all up and checking each and every hose + connection.

I do indeed swear by Millers' products but I'm not sure that's going to help you. Worth a try and you may experience some improvement however.
Click to expand...
Hi dj, I have had a misfire on cyl4 for about 18 months. The garage who serviced it back then found the fault code and informed me. I replaced all new Bosch plugs and ignition coils and left it at that. No major running issues, just an irregular idle.....other than when I went a bit silly with the throttle in 2nd gear and I got the EngM light flash a few times before it went out.
I mentioned it to a mechanic yesterday (different garage as have moved) and he confirmed the idling was in his words "lumpy" but didn't have time to look further as I was just having a minor service and MOT.
To the point, he said to diagnose he may have to remove the manifold (and check the injectors) and I'm assuming he was referring to the inlet manifold that you mention and recommend getting cleaned - I didn't yet enquire further with them as I thought it sounded like expensive work, and with no guarantee of resolving. As I said, idling aside, the running is not at all bad. Hence am here as was almost certain I would not be alone with this issue.
The garage seemed to think that these issues are starting to become more common with this type of engine. Cheers
 
simes2024 said:
Hi dj, I have had a misfire on cyl4 for about 18 months. The garage who serviced it back then found the fault code and informed me. I replaced all new Bosch plugs and ignition coils and left it at that. No major running issues, just an irregular idle.....other than when I went a bit silly with the throttle in 2nd gear and I got the EngM light flash a few times before it went out.
I mentioned it to a mechanic yesterday (different garage as have moved) and he confirmed the idling was in his words "lumpy" but didn't have time to look further as I was just having a minor service and MOT.
To the point, he said to diagnose he may have to remove the manifold (and check the injectors) and I'm assuming he was referring to the inlet manifold that you mention and recommend getting cleaned - I didn't yet enquire further with them as I thought it sounded like expensive work, and with no guarantee of resolving. As I said, idling aside, the running is not at all bad. Hence am here as was almost certain I would not be alone with this issue.
The garage seemed to think that these issues are starting to become more common with this type of engine. Cheers
Click to expand...
You are correct 'with no guarantee of resolving' but that would be the next logical step, the mechanic sounds like they have experience but I would still ask outright have you ever done this work on an A2 FSI. Would expect say 4 hours labour at what ever rate they charge, maybe the cost of gaskets (not too much) including cleaning the lower inlet manifold, insane not to do this with manifold off. Send off injectors to be professionally ultrasonically cleaned, say another £100 unless they have the means to do this, it is all mounting up and we are into the question is it worth it with the value of the car. Your profile shows mileage is 95k back in 2013 (unless updated since), what is it now and has this work been done before?

Sorry I feel I am rambling with points missed.

Like the question I should have asked first, do you use 99 octane petrol?

Andy
 
simes2024 said:
Hi dj, I have had a misfire on cyl4 for about 18 months. The garage who serviced it back then found the fault code and informed me. I replaced all new Bosch plugs and ignition coils and left it at that. No major running issues, just an irregular idle.....other than when I went a bit silly with the throttle in 2nd gear and I got the EngM light flash a few times before it went out.
I mentioned it to a mechanic yesterday (different garage as have moved) and he confirmed the idling was in his words "lumpy" but didn't have time to look further as I was just having a minor service and MOT.
To the point, he said to diagnose he may have to remove the manifold (and check the injectors) and I'm assuming he was referring to the inlet manifold that you mention and recommend getting cleaned - I didn't yet enquire further with them as I thought it sounded like expensive work, and with no guarantee of resolving. As I said, idling aside, the running is not at all bad. Hence am here as was almost certain I would not be alone with this issue.
The garage seemed to think that these issues are starting to become more common with this type of engine. Cheers
Click to expand...
First get a VCDS or OBD Eleven (ie VAG specific) scan. Then follow where the result points you.
Mac.
 
Andrew said:
You are correct 'with no guarantee of resolving' but that would be the next logical step, the mechanic sounds like they have experience but I would still ask outright have you ever done this work on an A2 FSI. Would expect say 4 hours labour at what ever rate they charge, maybe the cost of gaskets (not too much) including cleaning the lower inlet manifold, insane not to do this with manifold off. Send off injectors to be professionally ultrasonically cleaned, say another £100 unless they have the means to do this, it is all mounting up and we are into the question is it worth it with the value of the car. Your profile shows mileage is 95k back in 2013 (unless updated since), what is it now and has this work been done before?

Sorry I feel I am rambling with points missed.

Like the question I should have asked first, do you use 99 octane petrol?

Andy
Click to expand...
Thanks. Very helpful.
Yes I only use E5 petrol (and the occasional pot of redex) other than when I first got the car in Sep 20 I was initially unaware that I needed to.
Indeed they have worked on FSI, in fact my neighbour recommended them (he has a limited FSI - red with white panels and wheels, and some other unusual detailing)
Yes, my thoughts exactly on the cost vs value thing - up to 97k mileage now and currently doing under 5k miles a year. The car was a bargain as the previous owner had the old death pipe cooling issue which he couldn't be bothered to sort, so I did and it cost almost as much as I paid for the car....but I have no regrets.
I'll get back to them to ask for a cost estimate. Cheers
 
PlasticMac said:
First get a VCDS or OBD Eleven (ie VAG specific) scan. Then follow where the result points you.
Mac.
Click to expand...
I'm pretty sure they did that scan, unless of course you refer to a specific scan that can only be done by Audi or a VAG specialist (e.g Stealth)
Thanks
 
simes2024 said:
I'm pretty sure they did that scan, unless of course you refer to a specific scan that can only be done by Audi or a VAG specialist (e.g Stealth)
Thanks
Click to expand...
A VCDS scan is something that you can do yourself, if you are handy with a Windows laptop, but, first check the "Free Scan Register" on here, to maybe find a member not too far away, who will scan it for you.
The scan will tell you why you are getting an occasional EML light, as every time this, and any other fault conditions occur, they are logged in the ECU, and remain there, until cleared, by VCDS (or other VAG specific scan tools).
It'll tell you if you have a misfire, and if so, which cylinder.
No doubt there is something to be sorted, but without a scan report, you, and the garage, can only guess.
Good luck, an FSI, in good fettle, is a wonderful thing.
Mac.
PS: It's a good idea to share the scan report here.
 
PlasticMac said:
A VCDS scan is something that you can do yourself, if you are handy with a Windows laptop, but, first check the "Free Scan Register" on here, to maybe find a member not too far away, who will scan it for you.
The scan will tell you why you are getting an occasional EML light, as every time this, and any other fault conditions occur, they are logged in the ECU, and remain there, until cleared, by VCDS (or other VAG specific scan tools).
It'll tell you if you have a misfire, and if so, which cylinder.
No doubt there is something to be sorted, but without a scan report, you, and the garage, can only guess.
Good luck, an FSI, in good fettle, is a wonderful thing.
Mac.
PS: It's a good idea to share the scan report here.
Click to expand...
Hi PlasticMac,

The scan will tell you why you are getting an occasional EML light, as every time this, and any other fault conditions occur, they are logged in the ECU, and remain there, until cleared, by VCDS (or other VAG specific scan tools).
It'll tell you if you have a misfire, and if so, which cylinder.

Just to clarify what I said initially, both garages independently confirmed a misfire on Cyl 4 and subsequently cleared the fault codes, only for them to return obviously, as the misfire reoccurs.
I think my current garage is fairly clued up actually, as they have worked on my neighbour's FSI and sorted all his issues.
That said, areas 8 and 15 on the scan map are within my reach so I may contact them, even if it just results in a 'scan and social'....and in the mean time get a quote for an inlet manifold and injector cleanup

Best
 
If there's a problem with the inlet manifold flaps, the scan will show that. If there are no flap related errors logged, then no need to clean.
If there's a problem related to the injectors, I'd think there would be errors pointing to them.
Go for a scan and natter, post up the scan results.
You will probably need to clear all errors after the first scan, (but keep the results), then take it for a run, making sure you cover the whole rev range, up to at least 4500 rpm. The scan again.
Mac.
 
I don't think you will get a direct error for fuel injectors when they go bad.

I still think this is an end of life fuel injector, its too common in fsi for it not to be with that millage.
 
I had not heard that injector failure, at 100,000 plus was common in the FSI engine. If correct, then at the first failure all four should be replaced I guess.
Injector spray pattern is an important part of the FSI design.
Mac.
 
Bumblebee said:
I think this may be the last deduction with my perpetual No2 misfire. PO had an auto electrician check everything via the garage that always maintained it for PO and his final statement was a faulty injector.......
Click to expand...
You can check injector values with vcds, but I've not done this on the A2. It worked on the TT, so no reason why the FSI would be different.
Select Engine controller, then Group 13. Don't know values for the FSI, but if one injector is suspect, I'd expect to see an outlier value for it.
Mac.
 
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