Nissan Repair: 94 NISSAN PATHFINDER, what is a knock sensor, nissan pathfinder

Question
QUESTION: What is a knock sensor?

ANSWER: Hi Lukas -

A knock sensor protects the vehicle from energy robbing engine knock (when the engine fires before TDC and slams the piston against the walls). Engine knock also could ruin the engine on long term basis.

Hope this helps Lukas -
aloha' calvin


---------- FOLLOW-UP ----------

QUESTION: I recently bought this truck about 2 months ago and it's always run rough.  I replace all but 2 of the spark plugs because the are frozen in there.  The guy I bought it from didn't tell me about this.  What can I do?  Could it be why I'm having alot of problems?  Everytime I step on the gas the truck bogs on me.

Answer
Hi Lukas -

It is important that you get the other 2 plugs out and replace them. It helps to do that when the engine is hot. Get a long handle flex head rachet for better leverage. Might also want to spray some lubricant where the plugs are. If you get it moving, work it back and forth as you slowly remove the plugs. Hopefully they are not cross threaded.

Question for you - What color were the electrodes of the plugs you took out - brown (which is normal), black, wet (fouled)?

Aloha
calvin