ok first ive needed a knock sensor for a long time and i finally got it replaced on saturday nite (thanks maximagtr420). i replaced the knock sensor with about 195-200 miles on current tank of gas which left me almost at E. after the sensor change, i was able to squeeze almost 260miles out of that tank, something i havent done it a long time. so now im all happy and i fill up sunday morning. now ive driven about 130miles and im just a little above 1/4 tank. what gives?? the car is still pulling strong so the knock sensor is good. also i posted a week or 2 ago that my car was leaking some fluid from the passenger side, but everyone yelled at me for not being specific enough. it hasnt leaked the last couple of days and when i look in the engine and under the car i see nothing that is wet, so i dunno. also now when i start the car its very hard to start and im getting this high pitched squealing noise as it tries to start, but it stops as soon as the car is running. and one more thing, my car is vibrating a little now when i sit at red lights and idlinga t about 500-600rpm. help meeee

 

wish i could man, sometimes my car squeals when i crank it but never caused anything else to happen, other than making me freak at the terrible sounding noise.

Sometimes it may take a while for some mechanics to come around. Try this link while you are waiting

Nissan Online Mechanic

 

The squeeking is probably your starter. Go here to see how to regrease it. http://www.motorvate.ca/mvp.php/516

Ian

 

About how long does it take to get the starter out and reinstalled? Coming from someone who is only somewhat mechanically inclined?

 

hmm that seems like thats the problem for me, so 1 of my problems is sorta solved. anyone know about my horrific gas mileage tho? could it be my car is still adjusting to the new knock sensor?

 

Are your O2 sensors original ?? I usually get 130 miles on a 1/4 tank, not 3/4 of the tank...there is definetly soemthing wrong with your car

-matt

 

It shouldn't take you more than 30 minutes to get it out. All you have to do is take out the battery and the intake, then remove two bolts, disconnect the electric harness and it's out. Reinstall in reverse order. Good luck

Ian

 

my o2 sensors were all replaced, and i have no cel.

 

See if you can pull any codes from the ECU. Sometimes, eventhough there is no CEL, the computer is storing some codes and that might be your clue into partially solving your fuel consumption issues.

 

if you are hearing a sqeal, its probably not your starter. i could be wrong, but i just had the starter problem. and it makes more of a grinding sound, not a a squeal. the squeal is more likely a loose belt. just to save you the hassle of regreasing the starter. good luck tho.

 

I think it's a loose belt. Check your pulley tensioner. I didn't heed the signs, my car was telling me and my pulley tensioner fell off while I was driving and I was unable to drive it for a month. Check your belts and pulley tensioner Ceasar.

 

i was told by pep boys back in july or august that i needed a new belt tensioner, but i never got around to gettin it. could that be the squeal? if it is why does it only do it when i try 2 start the car but stops when the car is running?

 

My belts squeal only at startup too but stoped when the car was running. I don't see on how u need a new belt tensioner. You just have to retighten it. I have no clue on why it squeals on startup only. Hope this helps.

Iilac

 

well it finally happened, my car is dead. sitting out in the driveway it wont start. now i pulled the codes and got 0407 (crankshaft position sensor) and 0304 for knock sensor. yesterday it wouldnt start and i gave it a jump and it started right up, today it wont start at all even with a jump. now what the hell do i do and what is the crankshaft postion sensor?

 

a bad crankshaft position sensor won't allow the car to start. Sometimes a failing one can cause a knock sensor code. The crankshaft position sensor is located on the passenger side of the oil pan. You may want to check it and see if it's full of oil, or the wire going to it is disconnected or corroded. If not, then maybe it's dead. Check a haynes or chiltons to find out where it is. I don't remember how to test it right now.

If you replace the the crankshaft sensor, reset your ECU.

 

There's actually two crankshaft position sensors in the VQ. One is POS and the other is REF. Your 0407 code is for the REF side (which is by the oilpan - passenger side). The POS is by the tranny, very close in proximity to the front engine mount. The code for POS is different....0905 I believe (I got it when I was adjusting the engine idle speed the other day). I reset the ECU and it never came back. Anyhow, I just wanted to mention that there are are two codes and they point to two different CPS.

 

well it turns out this is what my car needed:
new starter, 2 front o2 sensors, coolant temp sensor, spark plugs and a fuel filter. now the cars runnin great! and the mileage is much improved. 70 miles and im just slightly under F!!!!! 70 miles used to get me to just above 1/2 tank!