XTTASY

Anyone experience this? I'm using Denso Iridium plugs, 15K miles on the plugs...

TT_Nuge

Check if the plugs are tight? One cylinder or all? Something here definitely doesn't sound right.

Take them out, make sure there's a washer, and only one washer on the plug and none in the seat area. Check the seat area for debris or gouges. Install new plugs or swap plugs from cylinder to cylinder if it's only one or a few of them doing it, see if trouble goes with the plug or stays with the hole.

CWK_Marin

The plug(s) doing that must not be properly installed or the seal is faulty because cylinder pressure should not blow by a properly installed spark plug with a correct seal.

I would recommend replacing the plugs with the correct kind specified for your TT. If you still have a problem, then the spark plug hole
in the cylinder head may be damaged.

TTagz

is the car actually running like that? it can't be running well if at all. isn't the coilpack bolted down? are you sure the coilpack isn't just loose and popping up off the spark plug?

Audiboy

Are you sure the plug is tight? If not, replace the plug and check again.

ncttrnl

Ditto... I've had this happen before. Check things are tight, replace if need be. No biggie.