After my 2001 Nissan Sentra (four cylinder) is warmed up and driven on the highway (especially uphill) car knocks ? (sounds like marbles hitting together) with loss of acceleration power, almost like car was going to stop. Also, on occasion, after adding ?Techron? saw white smoke out of tailpipe. Here?s what was done recently:
- Valve Cover replaced ? smelling oil ? smoke inside car
- Oil Change.
- Discovered problem.
- Put in ?Dry Gas.?
- Code reader showed #3 cylinder mis-firing.
- Changed spark plugs.
- Changed #3 coil
- Added ?Techron? to gas.
After applying #?s 4., 5., and 6., there was a slight improvement each time, but the problem still exists.
Any suggestions would be appreciated.
Larry