This is nuts. This was on my B8.5 A4 2.0T
Was tracking down a cyl 4 misfire and checked the plugs. Pulled all the plugs so I could compare to #4. All but one had a loose center insulator! They slid down to the tip and when jiggled upright, the ceramic slid back down. These are OEM NGK 06H905601A in the OEM packaging. less than 20k old at this point. Guess she's off the road until the new ones come in.
Symptoms: barely touching the accelerator pedal caused a jerky misfire feeling, but no flashing CEL. Light to Mid throttle felt good but over that and it struggled to accelerate with jerky misfires felt. All told, no codes, no set CEL or flashing CEL. Up to temp and cold start no difference.
I only found it because I checked the misfire counter and it showed #4.
Was tracking down a cyl 4 misfire and checked the plugs. Pulled all the plugs so I could compare to #4. All but one had a loose center insulator! They slid down to the tip and when jiggled upright, the ceramic slid back down. These are OEM NGK 06H905601A in the OEM packaging. less than 20k old at this point. Guess she's off the road until the new ones come in.
Symptoms: barely touching the accelerator pedal caused a jerky misfire feeling, but no flashing CEL. Light to Mid throttle felt good but over that and it struggled to accelerate with jerky misfires felt. All told, no codes, no set CEL or flashing CEL. Up to temp and cold start no difference.
I only found it because I checked the misfire counter and it showed #4.