Thank you for your advice. It is not a problem from on of the spark plug tips; plug is intact. And, yes, I neglected the oil in the cylinder to help determine if it is a valve or ring problems. I am used to the old rear wheel drive, cast iron motors; had several with over 300,000 miles on the original and untouched engines. This car, as much as I love driving it, the handling and ride, etc, is on it's second motor in 233,000, and likely I will try and get rid of it and possibly look around for an older, more trustworthy 940.