Misfire under load in 5th/6th gear - plugs or coils or both?

[Funky-gibbon]

2020 Polo GTI. (2.0 EA888 engine, no mods) On a couple of occasions recently my car has misfired when accelerating hard on the motorway between 50 and 70, in 5th or 6th gear. Gentler accelration in these gears doesn't misfire. If driving normally around town I also feel no misfire. Also no misfire while cruising steadily on the mototrway. No enigine management light showing.

Car currently has 26K miles. On original coil packs, plugs were last replaced two services ago around 10K miles ago. Next service is due in March and as I'm only doing around 5K miles a year was going to get the basic service again. But with this will probably get the plugs as well. Is it worth getting coils as well or just see how I get on with the plugs first?

[Simon_GH]

My 2019 Focus had a stutter under high load so easier to pick up in higher gears but present in every gear. I changed the plugs first but no difference. Then I bought a single coil and tried it on one cylinder (last one in the line because Murphy’s Law) and it’s been perfect ever since.

[Belle427]

A set of oe coil packs never hurts really, I dont see the need to do the plugs again personally though.
Swaptronics is never really a good way to find a fault to be honest though but they are a common issue on some Vag stuff.

[Dave.]

A code read will tell you which cylinder is missing, but as the coils will all be the same age, just get a full set.

[Simon_GH]

Belle427 said:

A set of oe coil packs never hurts really, I dont see the need to do the plugs again personally though.
Swaptronics is never really a good way to find a fault to be honest though but they are a common issue on some Vag stuff.

The only reason I went down the swaptronics route was the lack of error codes on both dash and garage grade code readers.

£46 for a genuine Ford coil seemed sensible but I didn’t fancy gambling with a full set just in case.

The coil symptoms with my car were basically driving fine until under load (load more than rpm).

[Belle427]

Live data is probably your friend here, monitoring the cylinders on a drive to see if anything looks unusual.

[Funky-gibbon]

Thanks guys.
Looking at the number of misfires in OBD11 it s pointing to cylinder 3 but I might as well do them all. If one has gone there s nothing stopping any of the others going soon.
Only question is do I go OE or aftermarket? I live quite near to Awesome GTI in Manchester and they have Racing Line for £42 each, APR for £52 each, or VW for £268 for the set of four.

Edited by Funky-gibbon on Sunday 21st December 14:28

[Belle427]

I would expect both of those aftermarket manufacturers to use quality components, not sure how you find that out though.

[Dave.]

For what it’s worth, I bought Bosch ones from ECP.

Only had them in the car for a month or two though.

[si_xsi]

When I got our EA888 coils replaced at VRS, it was stage 1 mapped and even they went for OEM parts as they said they were the most reliable.