Testing FSI ignition coils

s2ulk

Member
Hi all, does anybody know how I might test whether any of my four ignition coils on the FSI are faulty? At £25 a piece I would prefer not to buy a full new set unless necessary.

Thanks!
 

Proghound

Admin Team
If you have VCDS which can tell you which cylinders are misfiring, change those coils onto other cylinders. If the misfire follows the coils, they're the culprit. If you don't have VCDS, you need more known-good coils to test with. You're probably already aware that causes of misfires aren't limited to coils on these engines - VCDS is recommended for diagnosis.
 

PlasticMac

Member
If you have VCDS which can tell you which cylinders are misfiring, change those coils onto other cylinders. If the misfire follows the coils, they're the culprit. If you don't have VCDS, you need more known-good coils to test with. You're probably already aware that causes of misfires aren't limited to coils on these engines - VCDS is recommended for diagnosis.
I'd check the date codes on the coils, and any that are original fit, replace with Bosch or NGK. If one or two are duff, the rest will surely follow.
Mac
 

s2ulk

Member
I'd check the date codes on the coils, and any that are original fit, replace with Bosch or NGK. If one or two are duff, the rest will surely follow.
Mac
Thanks Mac, one is a Bosch (looks old) and the other three don’t have a label so I think I will end up changing all four. Can anybody share a part number for the Bosch spark plugs? Thanks
 

Catnip64

Member
Thanks Mac, one is a Bosch (looks old) and the other three don’t have a label so I think I will end up changing all four. Can anybody share a part number for the Bosch spark plugs? Thanks
7zap gives the following part numbers for the 1.6 FSI spark plugs:
Screenshot 2021-10-22 at 13.46.14.png
 

PlasticMac

Member
I think none of them are the originals, as they would all have Audi logo, and p/n.
Personally, I'd go for NGK for plugs, and for coil packs, NGK or Bosch.
Avoid cheapies.
Mac.
 

Evripidis

Member
I've done the following in the past for other cars via their diagnostic interface (VCDS equivalent). Not sure where in VCDS the coil pack output test is though because I haven't tried it yet.

0. Take out all 4 coil packs and attach the spark plug to each one of them.
1. Find the diagnostic output test for the ignition coils.
2. Use something to ground the spark plug body, e.g., jump lead.
3. Initiate the output test, this can either fire all 4 coil packs or one after the other or whatever combination.
4. Try and observe the spark on the respective plug.
5. Repeat for all spark plugs.
 

Andrew

A2OC Donor
@Andrew recommends the tri electrode plugs, I'm on ordinary single electrode, but will try them next time.
Mac.
Not tri!, 4 earth electrodes. Vague memory that the boffins decided four electrodes would best suit the FSI injector spray patterns, way beyond me.

Out of interest I Googled the Bosch and NGK 7zap numbers in the table that Catnip posted above.

Bosch

bosch spark plug.jpg
...

NGK....

ngk spark plug.jpg


Andy
 

steve54

Member
Denso IK20TT 4702 iridium spark plugs for me. fsi runs like a dream, 4000 miles now, no misfires ect. modern technology
got the heads-up from bretti_kivi some time ago

 

s2ulk

Member
Denso IK20TT 4702 iridium spark plugs for me. fsi runs like a dream, 4000 miles now, no misfires ect. modern technology
got the heads-up from bretti_kivi some time ago

Do you know what you had in before the Denso IK20TT plugs went in? There doesn’t seem to be consensus on here as to what is best as most the posts I’ve seen say that you should stick with what is in the manual which would be the Bosch FGR6HQE0 but I’ve seen a couple rave reviews for the Denso iridium now….
 
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