Old update: I replaced the last couple of coil packs the vibration is gone.
If you replace one you need to replace the rest soon after. You replace all the spark plugs at one time, but you don't replace all the coil packs, why?
The engine did get warm once in the dead of summer, like 100degrees...
Head gasket may not be problem
If it matters, I have a 2004 4Runner and have been on the search for the claimed head gasket issue. At about 185k miles my engine had rough start-up crank, vsc & trac lights came on, and decided to change all the spark plugs. No I hadn't followed proper...
