I have 06MT with 25,000 miles on it. I changed the engine oil (Mobil 1 5W-30 Full Synthetic) and STP Fuel Injector Cleaner recently.
Since a week ago, when I try to start the engine from the cold, the starting sounds seem like there is not enough power to start the engine. But It seems okay once the engine is warmed up. Sometimes, I have problem with starting the engine. I have to push the clutch pedal several times to start the engine. I think it is related to the little switch (on the wall) behind the clutch pedal.
Just want to know any idea from ya'll.

Peace~

 

Your battery may be starting to give out, if it's a weak starting problem you're having. If nothing is happening when you turn the key, as you have suggested by "having to push the clutch several times", you might have another problem. Like the clutch switch you described...

 

My battery is at 14 on the gauge which is above the middle.
Then I guess the clutch switch doesn't transfer the power correctly ?
Its weird that if the engine is warmed up, it seems no problem.

 

It's probably a weak battery. Even if the clutch switch isn't fully functional, when it is your car should start right up without having to slowly turn before firing up. Change the battery first

 

yeh +1 on the battery thing, your gauge cluster just reads running voltage

 

I went to local Autozone to check the battery status.
The battery condition was excellent
I might have to check the ignition switch at the local nissan service department

 

The problem was the clutch switch pedal position switch. I bought the part from Nissan dealer and did DIY. Just working good now.