Ever since I got my coyote going in my old Galaxie, I have had a rhythmic vibration at idle and at highway speed. It is a waa-waa-waa type vibration. Been slowly checking things, and today I did a compression check. 20k miles on motor, but I bought the motor used (5k) from a guy who was boosting it. 7 of the 8 cylinders went dead nuts 170-175 psi on my gauge. Motor was stone cold. The last cylinder (#3) consistently had 155-160 psi. Plug doesn't look different on #3. I added a tablespoon of oil to #1 and #3, and #1 came up to 195, #3 came up to 190 psi. I probably wouldn't ask the question if more than one had been off, and I checked #3 multiple times and got the same reading.
Motor makes plenty of power, gets good milage, and starts perfectly. Just wondering if I have an imbalance causing my idle and above 70 mph vibration.
Thoughts?
Motor makes plenty of power, gets good milage, and starts perfectly. Just wondering if I have an imbalance causing my idle and above 70 mph vibration.
Thoughts?
