Dear Scottie, excellent videos.  You are indeed highly knowledgeable (technically sound) and you can teach complex material to laypeople in an easy to understand way. Thank you for your invaluable service! I under immense peer pressure unfortunately caved in and finally changed my 2005 original gm/ac delco plugs for my 2005 Chevrolet Classic. I have 137k miles runs great car does transmission engine even ac..After changing the plugs (btw a couple were seized 😭) car runs rough and the other day car first time ever lunged forward a few times upon acceleration and even after shifting to Drive from Park. Whining sound from engine or perhaps transmission accompanied this surging. I drove home a mile very slowly. Opened spark plugs #4 was loose! Changed to a different set from Bosch 0.043 gap to ac delco #17 platinum 0.042 gap which is the exact spec listed in owners manual. Car is starting quietly again. But we noticed a little wetness perhaps gas on plug 1. I used to have oil coming at the top of valve cover over plug 4. But again never had any issues like this surging whining etc until after changing plugs. Do you think the spark plug hole in the engine cylinder may have been damaged (#1 or #4 especially?)? What should I do? Could it be perhaps damage to the cylinder head itself too? The oil dipstick is not milky nor is there any white smoke from exhaust. I did however a couple of weeks ago have to add coolant as my low radiator fluid light came on. It has not come on again since then. It's so sad that I changed the plugs finally. I wanted to leave them alone as the car was running smoothly with the original 2005 plugs! I certainly hope I haven't caused expensive damage. Incidentally I have a sealed transmission without a dipstick. How do I check the fluid level without a lift? Could low fluid level perhaps cause that surging? Will driving it again to see if it comes again damage anything further? I also have oil leaks over the years I simply add oil as needed in between changes. Would Steel Seal or any other product be good to add to help with any possible head gasket seal issues? And for oil leak would at-205 still be your recommendation? Kindly add anything you feel is important and helpful for me to know. I greatly appreciate your service to the public!

Best regards.

Sincerely,

Tim