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Yet another Knock Sensor Thread - 2002 S/C

30K views 37 replies 8 participants last post by  kms1990 
#1 · (Edited)
In another thread Dejablue wrote the following about an X that was dying and running rough, and had a bad KS code ...

the k/s has nothing to do with your problem . i would start simple fuel filter and then fuel pump.
So what are the symptoms of a bad knock sensor?

Recently my '02 X S/C has been sporadically running rough at Idle and actually died on me pulling into a parking lot on a steep grade. I had a hard time getting it restarted. I've also noticed poor gas mileage.

I took it to Auto Zone for a diagnostic today and it came back with the P0328 Knock Sensor code (no check engine light came on). Should I start by replacing the KS (man it's not cheap) or look into other things first (like the fuel filter mentioned)?

Edit, I did research the other threads on this thing but am just more confused.

So, what besides the knock sensor going bad could cause this code (without the check engine light going on)? What else could cause the symptoms I've mentioned? What should I try before replacing the sensor?

So far I've read:
• disconnect battery for a few hours and see if it goes away.
• replace air filter
• replace pcv valve
• replace fuel filter
• replace spark plugs/general tune-up
• replace fuel sending unit
• replace fuel pump
• replace distributor

Can All these things create a P0328 Knock Sensor code, and/or cause my vehicles symptoms?

I pretty much have no tools or place to work on it on my own, so I need to have a mechanic do anything other than really simple stuff that takes wrenches and screwdrivers.

I'm pissed. And have to say I'm wondering if I made the right choice buying this thing. I had no major problems with my 94 pathfinder (that I bought new and is still running) which is why I bought Nissan again, but after owning this X for two weeks I've dropped a bunch of cash already into repairs. And now this. Potentially another $800.00 or so. WTF. (edit: Sorry, I needed to vent my frustration)
 
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#2 ·
So, let me recap in case my above post is too convoluted ...
(and yes, I did search and read through a bunch of other threads on KS's, but it seemed to go all over the place and only ended up getting me more confused on what to do) ...

The symptoms:

• Rough, sputtering idle which gets worse as the vehicle sits at a stop light (acts like it's going to die, I have to pump the gas pedal to keep it going)
• Died (cut right out) on a steep grade as I was pulling into a parking lot.
• symptoms seem intermittent with no rhyme or reason to when it does this.
• Gas mileage seems unusually poor.
• P0328 Knock Sensor Code (circuit high input) - this code actually showed up twice during the same reading, the second said "pending". there were no other codes that appeared.
• Engine service light was NOT on.

Does this indeed sound like the symptoms of a bad Knock Sensor?
Or something else that is causing the KS to give me that code?

-- What is my best course of action?
-- What things should I try before dropping $800.00 to replace the knock sensor?
-- Are all the things I listed above (fuel filter, fuel sending unit, etc) worth trying first? Any others? or am I just throwing good money after bad if I do them? Is there any way to know?

Your help is greatly appreciated!!!!!
 
#3 ·
the k/s will not cause any of things on your list.a bad k/s with a s/c will cut your boost back and lower your gas mileage. there is something else wrong .first lets clean map sensor its in side the air horn unplug the wiring plug take the 2 clamps off remove the air horn get a can of map sensor cleaner 5dl auto zone dont touch the sensor spray on heavy let it dry reinstall. next find the ground wire valve cover to fender ground on the pass side remove the bolt on the fender replace with stainless steel bolt and washers .let see how it runs before we move on also lets see if cylenut can add some more input to the proble im sure we can get it running like new again so dont give up .
 
#4 ·
Deja is correct, you should not be seeing thoughs symptoms with just a KS. I cant judge much on what is wrong, but after you get the problem fixed, I can help with the KS issue. I did the relocation and cost about $80.00 Dont kick yourself too hard yet, About 8 months ago I was pretty upset with my X and the $ that had to go into it. With the help of this site, I got everything done for a fraction of the price and am now very happy with the X. Good luck!
 
#5 ·
Thanks Dejablue!!!

the k/s will not cause any of things on your list.a bad k/s with a s/c will cut your boost back and lower your gas mileage. there is something else wrong.
This sounds like really good news to me. I'm hopeful.

first lets clean map sensor, its inside the air horn. Unplug the wiring plug, take the 2 clamps off, remove the air horn, get a can of map sensor cleaner 5dl auto zone, dont touch the sensor, spray on heavy, let it dry, reinstall.
next find the ground wire valve cover to fender ground on the pass side, remove the bolt on the fender replace with stainless steel bolt and washers. let see how it runs before we move on also lets see if cylenut can add some more input to the proble im sure we can get it running like new again so dont give up.
I'll try to do this today ... it's actually warming up to 25 degrees today. :)
Thanks again!!! I really, really appreciate it!
 
#6 ·
Deja is correct, you should not be seeing thoughs symptoms with just a KS. I cant judge much on what is wrong, but after you get the problem fixed, I can help with the KS issue. I did the relocation and cost about $80.00 Dont kick yourself too hard yet, About 8 months ago I was pretty upset with my X and the $ that had to go into it. With the help of this site, I got everything done for a fraction of the price and am now very happy with the X. Good luck!
Thanks F150Boss86!!! I appreciate that! It's been really frustrating, but I am sure glad I found and joined this site. Great people and a fantastic resource!!!
 
#7 ·
OK, I pulled the MAF sensor, or at least I hope I did. Is this the correct part?




The sensor appears to have a black plastic "tube" sticking up. There is a small wire on one side towards the base, and one on the inside that I can see looking down it. I'm assuming those are the actual sensors. Do I spray down inside the tube and from the side? I have not touched the plastic tube at all.

Thanks!
 
#8 ·
yep thats it! give it a good cleaning.
 
#9 · (Edited)
Cool! Thanks Mac!!

OK, now here's a question, could having too much engine oil cause the symptoms I've described? I seem to remember reading that somewhere here.

I just checked it and it appears to be filled to where it's over the dipstick end and up onto the cable of the dipstick. The engine is cold and I checked it twice after wiping it off first. ?????

Edit: There hasn't been any noticeable blue smoke from the exhaust

-Dave
 
#11 ·
Next find the ground wire, valve cover to fender ground on the pass side, remove the bolt on the fender replace with stainless steel bolt and washers .let see how it runs before we move on also lets see if cylenut can add some more input to the proble im sure we can get it running like new again so dont give up .
I could not find the part you are describing, however I think this may be it...



It looks like a ground and is attached to the pass side exhaust manifold and runs to a clip on a bracket attached to the Pass fender, The bracket has two bolt screws holding it in place. The negative batter cable and a couple of hoses also attach to the bracket.

There are three wires attached to the drivers side fender with single bolts that I could see but none seemed to go to the valve cover.
 
#12 ·
i dont even have one of those anymore. It broke off...lol
 
#16 ·
Well, because of snow we ended up getting yesterday afternoon I wasn't able to go any further. I did put the MAF Sensor back in and was hopeful for a while because it seemed to be running great. Purring and Idling steady and smooth. Then all of the sudden (at a railroad crossing no less) it happened again. I had stopped, and as I started to accelerate it started running rough, nearly dying, I had to throw it in neutral and rev the engine to get her moving.

This morning it seemed to be running a little rough and lacking some power. Hesotating on acceleration. I did disconnect the battery for a few hours yesterday to reset the computer - I'm not sure if that is why it ran well for a while after I put it back together.

I'll try and get that Voltage meter today sometime.

I may also have the fuel filter and oil changed today if I have time - just to eliminate those as issues. Besides, I don't know when the previous owner did it last.
 
#18 · (Edited)
OK, I picked up a volt meter. I've never used one so please bear that in mind when telling me what to try next. ;)

Yesterday I had the oil changed and a new fuel filter put on. No difference.

I added two bottles of heet, so far no difference. In fact today it seemed worse. Seemed to loose power a couple times, put it in neutral, revved engine and it was OK.

It completely cut out on me three times without warning - engine just quit (no running rough first). All electrical stayed on. It started right up with no problem each time. All three times were when I had just moved out from a stop, or was going slow pulling into a parking space.

Seems that inclines and corners trigger it more often than not, but not always.

Still haven't had the chance to clean the ground bracket and replace the bolts, I had to work all day today, if It's nice enough outside tomorrow I'll give that a try next.
 
#20 · (Edited)
put the voltmeter on ohms (thats the horse shoe symbol on the dial) unhook the ground wire on the exmanifold side hook the red wire to it and the black to a ground on the engine ,and what #s are on the meter.
Hi Dejablue,

Here is the meter I picked up ...



The instructions are not written for a beginner. I understand I am to put the black test lead into the bottom right "COM" jack. I believe I am to plug the red test lead into the V(horse shoe symbol)mA (red 500V 200mAmax) Jack - Correct? (I'm not sure what the 10A "unfused" jack is for).

Which number do I set the dial at in the ohm section? The range is 200, 2000, 20K, 200K, 2000K.

I'm sorry for my ignorance on this, but I am happy to be learning so much. Thanks again for all your help!!!!!!!!!


Edit: For this test, Engine running or not? If not, ignition on or off?
 
#21 ·
the top 10amp un fused is to read voltage and word unfuse is a warning that if have the dial on the wrong voltage it going to be toast. the one you want is the center with red lead no run no ign all off.turn the dial to the 20k at 7pm and are ready to go. i have the same meter as my back up in the glove box.
 
#22 · (Edited)
the top 10amp un fused is to read voltage and word unfuse is a warning that if have the dial on the wrong voltage it going to be toast. the one you want is the center with red lead no run no ign all off.turn the dial to the 20k at 7pm and are ready to go. i have the same meter as my back up in the glove box.
Well, hopefully I did this right.

I couldn't get the test prong into the female end of the clip (where it attaches to the bracket), so I went through the other end of the clip to where the wire was crimped inside.

I tried it two ways just to see what I got

With the ground wire still hooked to the bracket, with red test prong inside the clip and the black grounded to the engine, The meter read 0.0

With the ground wire UNhooked from the bracket, with red test prong inside the clip, and the black grounded to the engine, The meter read 0.01

I found I had to hold the ground tester very still against the engine or the numbers jumped all over, but it seemed to always consistently come back to 0.01 when I was still.
 
#24 ·
I calculated my MPG on my last tank of gas and it came to 9.65 MPG. Ouch.

I cleaned the ground connectors and replaced the bolts (I did the ones on the other side also) and (knock on wood) it seems to be running good. I'm kind of holding my breath though and waiting for the engine to die or run rough. I also just filled up again and will recalculate my MPG on this tank of gas and see if there is a difference.

Thanks once again!!!
 
#26 ·
Argh!

Well, I spoke too soon. I ran out to pick up some supper and on the way back it started acting up again. I was driving 25 mph and noticed, even before I felt it, that the tach was jumping up and down from around 1000 to 1500 rpm with my foot not moving on the accelerator pedal, then it dropped almost to zero and back up again ... I put it in neutral and revved the engine and it acted like it was flooded. It started to sputter and sounded like it may have been backfiring. It finally cleared enough to drive it home.
 
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