You probably do not have one or more of the wires fully seated on the plug ends. Make sure they "click" into place.
try changing the spark plug wires also
Bad spark plugs, spark plugs wires, etc.
the transmition ,is probably not adjusted to the spark plugs,or their not the right spark plugs
Yes, fouled spark plugs can cause engine shaking, and loss or power. I'm not sure about knocking but I'd guess that too.
Check/replace Rotor Check for spark at plugs
I would replace the spark plugs after 50K, the wires and plugs again at 100K.
The spark plugs on a 1999 Mercury Cougar are located under the cover of the engine. The spark plugs should be changed approximately every 60,000 miles.
The manufacturer recommends that the spark plugs are changed every 30,000 miles. Many individuals have experienced a much longer life for the spark plugs.
30000 miles
No. Spark plugs have nothing to do with your turn signals. Try changing the turn signal bulbs. Spark plugs are only used for the combustion of the engine.
Once on 1-2 year on regular spark plugs. Once every there years on High end spark plugs.
The spark plugs on a 1999 Mercury Cougar are located under the cover of the engine. The spark plugs should be changed approximately every 60,000 miles or so.