I have a 2007 Tahoe with 130,000 miles in pristine shape. I was told at the dealer that I have a bad ring in cylinder #1 causing oil to foul the spark plug. The service manager told me that it will eventually need a new engine down the road. I am looking forward to the future and debating whether to spring for the purchase of a different vehicle before the problem gets worse or wait till the problem gets worse and I need to replace the motor and if so, what would be the cost of a rebuilt engine plus installation. The body is perfect and the transmission was replaced 2 years ago.