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94 Pathy

Replacing your knock sensor, 90-95 VG30E

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:unsure: Alright, sorry for the long delay! I hope I'm not too late!

 

First thing is first. Make sure you have all the correct tools needed. The only one I needed to get was the hex socket for the manifold bolts.

1.Drain your radiator fluid.

2.You'll need to take all the upper intake manifold. Be sure to label all the hoses and cables where they go.

3.Removing the throttle cable and necessary brackets also.

4.Using a hex-type socket, remove the manifold bolts.

5.remove the manifold.

6.Release the locktabs in order to unfasten the fuel injector connections.....BECAREFUL not to damage the connectors.

7.Remove the fuel lines from the fuel rail....(I did not do this, you don't need too if you don't want.)

8.Remove the fuel rails by hex-type socket or allen wrench.

9.Remove fuel rails with the injectors installed.

10.Now you will have to remove the lower intake manifold.

11.The unit bolted to the top of the engine block with a cable connected is the knock sensor.

12.The connector also has a locktab.

13.Unbolt the sensor and replace.

14.Clean all the old gasket off where the new ones must go.

15.Now you are repeating the steps, but backwards.

16.If need be, You might want to replace your O-rings. I didn't because of the engine swap I will be doing in the near future. I haven't noticed any differance in the fuel consumption and horsepower.

 

Good luck and enjoy a few beers while working on this. If you have a buddy to help, it will go alot quicker.

Let me know how it goes.

 

Travis

94 Pathy :beer:

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You'd be best off to replace the o-rings on the injectors, for safety's sake. You wouldn't want a leaking injector to hold you up after reinstalling the whole thing. ;)

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Yeah, it would only take me a few hours to do. Right now though I have other toys to purchase :D

 

I know, I know, saftey of the vehicle and me come first. I'll have to get some ordered.

 

Thanks for looking out for me! :)

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Sonuva... how long did this take you, and what would you rate it for difficulty on a 1-10. My Pathy started acting up last night. :furious: 94 with a 5sp and I just got it out of the shop with a new clutch, so money isn't so great right now. It runs and drives prefect, but won't idle to save its life sometimes. Not always, generally when its warm. I sputters and sometimes dies coming to a stop. Just pulled the codes and I'm getting 34, Knock Sensor. By the way, what does the knock sensor do anyways?

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I am going to start on this project tonight, what do I need other than the knock sensor, should I buy radiator fluid or what, bear with me, because I know a little less than nothing about engines

 

Edit: should I buy any gaskets or something

Edited by Jdpathy

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I am going to start on this project tonight, what do I need other than the knock sensor, should I buy radiator fluid or what, bear with me, because I know a little less than nothing about engines

 

Edit: should I buy any gaskets or something

Gaskets... as a rule, if you remove it you need a new gasket (or sealant) for it ;) You do not need new valve cover gaskets unless your are truly toast... they are made of rubber and are reusable.

 

You will need "at least" throttle body and intake manifold gaskets

 

Look through your manual and get completely familiar with he process before starting. This will also give you an idea of what exactly you are going to need.

 

How long has it been since you changed the coolant? If it has been several years, or you don't know then it's time.

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the manual gives me steps for diagnosing it, it tells me to find pin 27 on the ecu harness and check for continuity between pin e on the det sensor.

 

I can't find pin 27

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You do not need new valve cover gaskets unless yours are truly toast...
why are we removing the Valve Covers??? are they leaking? No Leaks just make sure they are all torqued to spec before putting the plenum back on.

 

throttle body
That will come off with the Intake Plenum, leave it alone....

 

Once you remove the Plenum, see if you can reach in under the lower Intake from the back side... I was able to on my 91... its either a 10mm or a 12mm (patients)

 

On the back side of the Plenum there is a Vaccuum line, and 2 coolant hoses, disco the hoses on the firewall side not from the Plenum assembly... and the breather hose from the right side valve cover, disco from the Valve Cover...

 

My $.02 on the how to... buy a book or 3

Power wash the engine compartment(did that the 2nd time I took it off)

Garage

 

1.remove hood for accessability(maybe over kill but you will appreciate the room and the light)

2. disco battery

3. pop the top of the air box disco MAF connector, remove air box lid and MAF Assy

4. mark and remove small vaccuum hoses from charcoal canister and intake tube and thorttle body, Remove intake tube.

5. disco throttle and CC Cables(2 10mm bolts then) slip them up and under the wiper out of the way.

6.On the back side of the Plenum there is a Vaccuum line, and 2 coolant hoses, disco the hoses on the firewall side not from the Plenum assembly... and the breather hose from the right side valve cover, disco from the Valve Cover...

7. Brake Vaccuum hose(spin it 90* it will stay out of the way)

8. You can remove the plug cables individually or pop the whole cap, disco the cables from the spark plugs.

 

9. (may have a loosening patern) Break torque on the Hex head bolts down the center of the plenum, then remove them careful not to drop the washers(did that too)

 

10. Plenum should be movable but there is 1 electical connecter hiding on the back drivers side, disco that and the whole assembly should come off...

 

Be Very Careful not to let anything fall in the exposed intake.

 

Now 80% of the mass is out of the way, climb in, reach around the back and see if you can get to the knock sensor(slick has a pic)

 

If not follow the procedure in the Manal for removing the lower intake.

 

Before you put it all back together... Good time to change the plugs

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Heck my knock sensor has been bad for years....over 4 years for certain! still runs great so I am not going to mess with it yet.

 

thank you nissan for putting it in such an easy to get to place!!

 

Thats why I am not going to deal with it yet.....because its too expensive to pay a mechanic to do it and I can't have my pathy in my garage torn apart for too long at a time right now.

 

Nissan specialists told me to just leave it be as long as it is still running great.

 

mine is a 1990 se

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why are we removing the Valve Covers??? are they leaking? No Leaks just make sure they are all torqued to spec before putting the plenum back on.

meh... don't know what I was thinking :crazy:

 

BUT, at least know he knows :lol:

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Yeah, I'm not gettithe whole vlave cover issue either. I didn't take mine off. I hope all went well for those of you who had to replace your knock sensors. So far, my Pathy has been running good.

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i had my pathy start to run in safe mode i ran the code then went to radio shack and bought the proper meg ohm resistor and bridged it for about 3.00 and an hour tops i fixed mine i took an hour because i had to keep looking at the factory service manuals and checking with my ohms meter to make sure i was splicing into the right ones......that was fine for me as i dont need a knock sensor, i can hear my engine if it knocks or bumps and i always use preim gas anyway....... yet i havent had either the cash to let nissan do it( i really dont want to tear the top down by myself let them do it and if things break its on them) or the time to do it my self yet.

thts probly a main reason it got sold when they thought they needed to put probably at least a grand into it ,but i don't have any idea what it might cost

 

email me if you still need help i think i still got all the old pics and tech data

 

ps I heard if the knock sensor starts to work again it will go into safe mode and you would need to remove the resistor u put in???

seems like once its bridged it would be fine no matter......mine has never had a problem since i put the resistor in mine....at least not a prob related to tht

Edited by pathfinderfisherman

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I am new here guys, i appreciate the info in the forum, im about change the knock sensor in my 99 Pathfinder.My truck stall out, the codes shown was the Maf, Knock and TPS all at one time, i love my Pathfinder but damn.....oh and Crank sensor, am i just bad lucky or is this what Pathfinders do? or is it this particular year?

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... am i just bad lucky or is this what Pathfinders do? or is it this particular year?

 

 

Here's to hoping your one lucky guy! :friday:

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Kind of an update with the knock sensor.....

 

I replaced the sensor in this other Pathy & didn't have to pull the fuel rails or injectors, or the valve covers. only the upper plenium & lower plenium. just needed sensor & gaskets & good to go. This 2nd time only took me a few hrs to do. Never did have issues with the 1st Pathy when I didn't replace the O-rings. Still runs better then this Pathy. Hopefully not after I'm done with everything. Good luck to all that has to do this replacement. Holla if you have questions.

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Questions:

 

1. After replacing a knock sensor on my 93, is there anything that has to be done other than clearing the check engine light?

For example, do I have this "safe mode" thing? Because my vehicle seems like it doesn't have any power unless I almost floor the gas pedal?

I've replaced my knock sensor and my Cat Converter, and it still seems like I have little power. Or were Pathy's simply made this way?

 

2. I wish I had heard about this "before" I replaced the knock sensor so it would have been easier, but has anyone "moved" their knock sensor, attaching it to the top screws of the manifold for example?

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1) Clearing the codes in the ECU is all there is. Sounds like you might still have some issues?? No, the Pathys don't have a huge amount of power, but they certainly can get out of their own way.

 

2) MaritimeMan had disconnected his knock sensor and installed a new one on the bellhousing. It seemed to work fine...

 

I am new here guys, i appreciate the info in the forum, im about change the knock sensor in my 99 Pathfinder.My truck stall out, the codes shown was the Maf, Knock and TPS all at one time, i love my Pathfinder but damn.....oh and Crank sensor, am i just bad lucky or is this what Pathfinders do? or is it this particular year?

Check the MAF, TPS first, clear the codes, check the crank angle sensor and worry about the knock sensor last as having an engine knock will trip the sensor.

 

B

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Does anybody know if replacing the knock sensor actually makes a noticeable difference? My codes say it needs replacing, but I don't want to spend the time and money to replace it haha. My pathfinder has some trouble getting up to 100km/hr, as well as going up hills its not the greatest.

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The knock sensor can be set off by different things. Even a rusty/loose exhaust shield. Seeing how its sort of a pain to get to, I'd exhaust all efforts to make sure it is the knock sensor and not something else.

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Does anybody know if replacing the knock sensor actually makes a noticeable difference? My codes say it needs replacing, but I don't want to spend the time and money to replace it haha. My pathfinder has some trouble getting up to 100km/hr, as well as going up hills its not the greatest.

 

 

yes it should help with this issue, as the knock sensor dials back timing and gas to the engine when it detects a knock. up hill power loss, and lagging 0 to 60 r common.

probably a million yrs late on the subject but oh well hehe.

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I just want to be sure this is my issue before i go tearing it apart. My pathfiner 1993 started to spit and sputter whenever im driving. It doesnt die on me when i come to stops or anything but after sitting all night my first drive of the morning it will run fine with no sputtering when i oress on the gas but after 20 minutes to warm up it wont stop sputtering to save its life.

Does that sound like symptoms of a badknock sensor??

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Doesn't sound like KS to me. Sounds more like a bad O2.

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:unsure: Alright, sorry for the long delay! I hope I'm not too late!

 

First thing is first. Make sure you have all the correct tools needed. The only one I needed to get was the hex socket for the manifold bolts.

1.Drain your radiator fluid.

2.You'll need to take all the upper intake manifold. Be sure to label all the hoses and cables where they go.

3.Removing the throttle cable and necessary brackets also.

4.Using a hex-type socket, remove the manifold bolts.

5.remove the manifold.

6.Release the locktabs in order to unfasten the fuel injector connections.....BECAREFUL not to damage the connectors.

7.Remove the fuel lines from the fuel rail....(I did not do this, you don't need too if you don't want.)

8.Remove the fuel rails by hex-type socket or allen wrench.

9.Remove fuel rails with the injectors installed.

10.Now you will have to remove the lower intake manifold.

11.The unit bolted to the top of the engine block with a cable connected is the knock sensor.

12.The connector also has a locktab.

13.Unbolt the sensor and replace.

14.Clean all the old gasket off where the new ones must go.

15.Now you are repeating the steps, but backwards.

16.If need be, You might want to replace your O-rings. I didn't because of the engine swap I will be doing in the near future. I haven't noticed any differance in the fuel consumption and horsepower.

 

Good luck and enjoy a few beers while working on this. If you have a buddy to help, it will go alot quicker.

Let me know how it goes.

 

Travis

94 Pathy :beer:

why are we removing the Valve Covers??? are they leaking? No Leaks just make sure they are all torqued to spec before putting the plenum back on.

 

That will come off with the Intake Plenum, leave it alone....

 

Once you remove the Plenum, see if you can reach in under the lower Intake from the back side... I was able to on my 91... its either a 10mm or a 12mm (patients)

 

On the back side of the Plenum there is a Vaccuum line, and 2 coolant hoses, disco the hoses on the firewall side not from the Plenum assembly... and the breather hose from the right side valve cover, disco from the Valve Cover...

 

My $.02 on the how to... buy a book or 3

Power wash the engine compartment(did that the 2nd time I took it off)

Garage

 

1.remove hood for accessability(maybe over kill but you will appreciate the room and the light)

2. disco battery

3. pop the top of the air box disco MAF connector, remove air box lid and MAF Assy

4. mark and remove small vaccuum hoses from charcoal canister and intake tube and thorttle body, Remove intake tube.

5. disco throttle and CC Cables(2 10mm bolts then) slip them up and under the wiper out of the way.

6.On the back side of the Plenum there is a Vaccuum line, and 2 coolant hoses, disco the hoses on the firewall side not from the Plenum assembly... and the breather hose from the right side valve cover, disco from the Valve Cover...

7. Brake Vaccuum hose(spin it 90* it will stay out of the way)

8. You can remove the plug cables individually or pop the whole cap, disco the cables from the spark plugs.

 

9. (may have a loosening patern) Break torque on the Hex head bolts down the center of the plenum, then remove them careful not to drop the washers(did that too)

 

10. Plenum should be movable but there is 1 electical connecter hiding on the back drivers side, disco that and the whole assembly should come off...

 

Be Very Careful not to let anything fall in the exposed intake.

 

Now 80% of the mass is out of the way, climb in, reach around the back and see if you can get to the knock sensor(slick has a pic)

 

If not follow the procedure in the Manal for removing the lower intake.

 

Before you put it all back together... Good time to change the plugs

try this again... All this info is great, however it's missing one thing... there one small bolt that threads through timing cover housing flange that also threads into the coolant elbow at the front of the intake. To get to this bolt, I had to also remove the tensioning pulley mounting plate. Once that is all done, viola. Intake manifold comes right off. I might have damaged the timing cover in this process. TBD. Anyway all is good now just waiting for the KS and need to find the hose for that elbow too, it's toast, aged and I'm not trusting it to go back on. Thanks all. Cheers.

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