Will_M1911

Whelp. My 2004 coupe is completely stock engine-wise but The spark plug for cylinder #4 blew out the hole, taking the threads with it.

Anyone ever used a Timesert on one of these cars? Can it be safely done by a mechanically inclined person who has never used one before?

C5Luv'R

I have not done this for an LS1, but I did successfully install a Heli-Coil into the cylinder head of a Quad-4 engine when it was still assembled.

Why it occurred: I tried changing spark plugs when the engine was not completely cold. The #2 spark plug stripped out

How I fixed it: I bought a Heli-Coil kit in the correct thread size and length. Used the tap in the kit, packed it the flutes of the tap with grease, and only did 1/4 of a turn at a time. The aluminum chips from the cutting the larger thread into the cylinder head were caught in the grease rather than falling into the engine. It took about 1.5 hours to tap the hole. Then installed the Heli-Coil and CAREFULLY broke off the tang with a long reach needle nose pliers. To be safe, I then rigged up surgical tubing to my shop vac and vacuumed the inside of the cylinder for any chips that may have fallen. Installed the spark plug & coil, stated it up and drive that car another 110k miles after this repair.

Will_M1911

I just ordered a Timesert kit. They claim it can be done "over the fender" without removing the heads. I'll probably do a write-up since I didn't find any old threads on the process and it might help someone in the future.

I paid for 2nd day shipping so assuming it gets here this weekend, I'll drill and tap the hole, install the insert, and rent a bore scope to inspect the cylinder for shavings and blow/vacuum them out until it's clean.

Wish me luck. Any tips, advice, reassurance is still appreciated while this thread is open.

C5MSG2004Vert

I do wish you luck. It definitely can be done as a process, but you have to have clear access to the spark plug hole and be able to drill and get the tap in there and install the insert.

Will_M1911

The car gods have smiled on me today.

I never have this kind of luck, but I decided to check all the other plugs and 6 of 8 were loose. Found my torque wrench and everything torqued down to 11ftlbs. #4 must have just worked itself loose enough to pop out. No need to tap any threads it seems.

vette4fl

V8 Ford trucks back in the 60’s were known to spit up spark plugs like that.

Thankfully yours turned out in your favor!

grinder11

Hmmmmm.........I thought I'd posted something here about an expanding tap that works backwards, but it ended up in Cyberspace. I see OP has made out OK, which is great. But I'll try again to help those less fortunate. I first saw these at least 15-20 years ago in a motorcycle magazine. Theyre awesome!! Powerbuilt makes these expressly for repairing spark plug threads WITHOUT pulling the heads. It's one of those items that you instantly think, 'Gee, why didn't I think of that.'

Will_M1911

The Timesert kit is advertised as being able to do the job without pulling the heads. However someone definitely should make an expanding tap like you describe. It would greatly reduce the debris down in the cylinder.

grinder11

I see OP has made out OK, which is great. But I'll try to help those less fortunate. I first saw these at least 15-20 years ago in a motorcycle magazine. Theyre awesome!! Powerbuilt makes these expressly for repairing spark plug threads WITHOUT pulling the heads. I'm pretty sure theyre called Powerbuilt Expanding Back Taps. It's one of those items that you instantly think, 'Gee, why didn't I think of that.'