ARP 100-9904 PTFE Thread Sealer - 1.69oz. Tube

I used this to seal up SBC head studs. Works good, but you still need to make sure everything is torqued appropriately

Seamed to work as directed.

Fait de la belle job.

Awesome product! The ONLY thing I will use when building a motor that has bolts that penetrate the water jacket!

This is the best thread sealer for automotive application. I was replacing the coolant temperature sensor for the 2004 GMC Envoy 4.2l I6 Atlas engine (one of the smoothest idling GM engines). I ordered the factory part from GM and changed it out. The next day I noticed a coolant leak. The factory part comes with white thread sealer, dry, on the threads all ready for installation. However, the sealer was not working as it should. I removed the part and did a visual inspection. I did not see any issues with the threads. I did chase the threads to make sure there were no burrs. Then, I put this thread sealer on the threads making sure I only covered the same area as the factory thread sealer. You don't want to cover all the threads as you will lose a the electrical ground connection. After installation, watched for leaks every day for a week. Problem solved!