Wrong spark plugs?

[Teeka56]

Checked with dealer, it takes the 26mm reach plug. It had been running for quite awhile with short plug!

Still have misfire, moving coils to isolate which one is suspect.

Thanks for your help!

[pgill]

If it were me I would try using the Denso TT plugs

Denso (4704) IKH20TT

I switched to Denso TT plugs for my Audi 2.0T because the Denso Plugs worked so well in my two Volvo engines

The idle and throttle response with the TT plugs is so much better.

Based on my research the big advantages of the TT (twin Tip) plug are the resistance to quenching the flame and the consistency of flame initiation.

One consideration is the heat range.

For Denso a higher number indicates a plug that can handle higher temperatures

If you are getting misfires is it during wide open throttle climbing a hill or is it at idle?

A high load misfire may require a colder (higher number then 20) spark plug

A misfire at idle or while cruising is a perfect candidate for the IKH20TT

Check the data when the miss fire was detected using an ODBII code reader

Good luck

Paul

[Teeka56]

This car was idling on 3 cylinders. The scan tool said 4,5 were misfiring. Replaced plugs and now only 4 is misfiring. Moved coil to 2, and now 2 is coming up ( P0302).

I will check those plugs out for my C30 T5. I had used in the past on watercooled VW’s a WR7DTC- triple electrode. I was surprised at the difference at idle/throttle response as you noticed too.

[RickHaleParker]

Moved coil to 2, and now 2 is coming up ( P0302).

Before you toss the coil, try cleaning it's electrical connection. Also the metal pad under the bolt is a ground, make sure it is clean.

[chrism]

A handy little tool for these situations is a simple little thing called a Grip Scale. It’s a crochet hook looking thing that measures the depth of a hole and is usually marked in 1/16” or 1/32” increments. It may also be available in mm - I’m not sure.

https://www.usatco.com/item/GRIP%2BSCALES/Grip-Gauges/