Crankshaft Sensor on QG18de (the one in the back)

[Incognito]

People,

Where do I find the crankshaft sensor on the qg18de? ... the one that is supposed to be behind the engine. (I know the camshaft sensor is on the left side (below the engine oil cover).

The ckshft sensor is supposed to be behind the engine, but for the life of me I just cannot locate it!!! ...i looked form on top, from under the car, sieways, cokey-eye, but still no luck...

Could somene pleeeeze enlighten me?

[JWT]

both sensors at to the left side of the engine look to the bottom left you will see it

and if you want it to buy check massey or motorist
do not buy this item forign used

[sparkie]

This is an excerpt from the UK FSM. I know the camshaft sensor is up on the head on the right side more foward on the head (reads off the exhaust cam gear). The knock sensor is down behind the block near the oil filter. I have never looked for the crank sensor, it may not exist in JDM vehicles, pay particualr attention to the last part of the exerpt, usually if the item is not needed for engine control it won't be included in JDM engines. Camshaft angle alone is sufficient to run any chain driven engine, all the SR's run quite well with just camshaft angle.

Component Description
NCEC0551
The crankshaft position sensor is located on the right rear wall of
the cylinder block in relation to the signal plate on the No. 6 counterweight.
The crankshaft position sensor is a basic component of the engine
control system. It monitors engine speed, piston position, and fluctuation
of the engine revolution. These input signals to the engine
control system are used to control fuel injection, ignition timing and
other functions.
The sensor consists of a permanent magnet, core and coil.
When the engine is running, the high and low parts of the teeth
cause the gap with the sensor to change.
The signal plate is provided with 34 teeth to emit a signal at an
interval of 10° during crankshaft operations. However, it is not provided
with 2 teeth to emit a signal at an interval of 180°.
The changing gap causes the magnetic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor
changes.
The ECM receives a voltage signal to provide ‘‘time processing’’ for
engine speed, piston position and fluctuation of engine revolutions.
This sensor is not used to control the engine system. It is used only
for the on board diagnosis.

CRANK sensor


CAM sensor

[Incognito]

I have that UK FSM as well, but it didn't help me much in locating the sensor. From the broken line it suggests that something is blocking the view.

Believe me, I laid myself under the car for a long time trying to see where this thing is, running my hans trying to feel it, but no luck.

Do I have to remove anything? the only thing I could think of that I have to remove to get to it is the intake manifold!!! ....I really do not want to do that. All I want to do is get at the harness connector so I can do some checks with my multimeter.

I would appreciate any help....

[Incognito]

Sparkie,

I believe you may be correct in that the crank sensor may not exist!!!

When looking at the UK FSM, and at my engine, I am only seeing the knock sensor. No crankshaft sensor!!!!!

However, the camshaft sensor is as indicated in the FSM...


Another anomaly with the UK FSM for Primera.... The Fuse box and relay arrangement (under the steering wheel) are different to my JDM Primera. The arrangement of the JDM is however similar to the arrangement described in the Infiniti G20 FSM.

[sparkie]

I believe I am correct as well but I have had the same suspicions about Santa Claus and the Tooth Fairy as well, then every year hollywood makes a new movie providing incontrovertible evidence and I recant my heresy.

Although JWT might have conclusive proof of the existance of this sensor

both sensors at to the left side of the engine look to the bottom left you will see it

He makes these statements with such conviction you can almost feel god speaking tru him. Check him for a pic of the loch ness monster one time.

As a point of interest I am also looking for the lock washer monster that has taken many a washer while I was dismantling stuff.


JDM is different for many reasons, UK/Europe and US are different for legislative reasons relating to OBD-II, the newer J2534 pass thru and emissions control.

Just use the UK or US manual as a guide, print it out and edit it as u go along to reflect what actually exists in your car. U woudn't believe how much you forget when you go back to it a few months later and then have to do all that figuring out all over again.

[Incognito]

JWT, you did say lower left side? One sensor is located near the upper half. Difficult to understand why nissan would put another amidst all those pulleys, ....tts difficult to see anything with all those pulleys and belts ... I will get my flashlight tomorrow and go searching for that second sensor, assuming that it does exist.

So far I have felt like a blind man in a strange land in search of the mythical Unicorn.... but the search goes on.....

I wonder if anyone with qg15 and qg16 came across it?

[JWT]

hmm considering i had a qg18de engine
hmm m

neways i drive a subaru now

[ziggy_dappa]

i changed de crank an cam sensors on my gq16 , guess they are in the same place as de qg18. the crank sensor is under the car right next to the starter motor. it reads the teeth on the flywheel to its close to the end of the block.

[sparkie]

ziggy was your QG16 a singapore or local vehicle?

[JWT]

if these parts were bad the car would cut off and never start back it will just tumble

so why change them if they are not iving trouble

also these sensors were $250 for 1 thas howmuchi paid back in the day now i hear they are for much much more

[ziggy_dappa]

ziggy was your QG16 a singapore or local vehicle?

yea
its ah singapore N16

if these parts were bad the car would cut off and never start back it will just tumble

so why change them if they are not iving trouble

also these sensors were $250 for 1 thas howmuchi paid back in the day now i hear they are for much much more

nissan had a recall on some cars fitted with qg engine stating they had faulty cam and crank sensors. on de website had a range of chassis numbers of cars that were suspected to have these faulty sensors, mine wuz one of them.
i never had problems but as u said the car wud cut off an nut start back if de sensor went, jus did'nt want dat to happen to me. so went an bought 2 new ones from morotist, they were about $220 each i think.

[Incognito]

Sparkie,

You know if they also leave out the second oxygen sensor (rear) on JDM vehicles?

I am going to remain quiet for a few days until I can take some photos and post it for everyone to see...

[Incognito]

Ziggy dappa is correct ...its close to the Starter motor.

Apparently the JDM Primeras do not have the sensor located as indicated in the Primera-UK FSM.

However, if you look at the B15 Sentra (USA) FSM, these also come with qg18de, you will see that the crank sensor is close to the starter motor.

PROBLEM:- The sensor is not coming out!!!! ....the bolt came off easy enough, but the sensor is just spinning in its socket, BUT WOULD NOT COME OUT!!!! Spent over an hour trying to get this thing out. Any advice?

[Incognito]

Sparkie,

I think we owe JWT a half-apology..... (He got the location wrong, but maybe its another nissan qg18de configuration????, was it qg18dd?)

I think Nissan made qg18de variations with parts rearranged just to confuse the crap out of everyone!

BTW - CK sensor came out. apparently the o-ring on the sensor was kind of stuck in the hole...Nevertheless, its one of the most inconvenient places to access a sensor. The location indicated on the UK FSM seem to be a slightly little more convenient...

[ziggy_dappa]

^^ good to hear u got tru.
i ketch my a$% to get mine out too. endup usin ah flat head to pry it out.

[sparkie]

At least we know the sensor exists in your model. As I said I never looked for it b/c it shouldn't stop the car from running, it should just give you an engine check light. Looking at the FSM again the information is conflicting.

Did you try unplugging it while the car is running and see what was the effect? Or try to start with it unplugged? If you haven't would you mind doing it and telling us?

The camshaft sensor is in the same place in all QG I have seen, even the DD, and that is by the exhaust cam sprocket on the head. This is the only sensor should stop you dead in your tracks.

Glad you get tru as well.

You could put back up the sensor with some grease in the mounting hole, what happens is that on the outside of the o-ring the aluminum corrodes and forms like a shoulder making it hard to come off. Also, you could sand the hole lightly and use a thin coat of spray urethane. Same thing happens with speed sensor etc. A lot of time sensor ends up breaking.

[Incognito]

Sparkie,

Your suggestions are well noted. Unless you are a contortionist, some might be quite difficult to do while lying under your car. I would recommend to do this while your car is on a ramp, it might be easier.

Next time I get the urge to crawl back under my car I will try starting the car with the sensor disengaged.... maybe in a couple of weeks when I have to change engine oil... (i will do it before changing the oil of course )

Ziggy dappa ....the flat-head turned out to be my saviour ....I recommend using one with a fat handle and a fairly wide flat-head. Also, using a pliers to grab it and pull it out is useless. Flat-head is the way to go...

[Pebblecrusher]

Found some decent pics online that might help with the location of the hard to reach crankshaft sensor.

http://www.findonefindall.com/nissansen ... ap0335.htm

Hope this helps.

[achillies]

good info here

[X_Factor]

whats the symptoms of a faulty crankshaft sensor on the engine?
engine check light is not on
car is burning a lot of gas (struggle to get 250k's ) on a tank and little power under 2500 rpm

[Incognito]

Its a long time I have been on here, and pleasantly surprised that a topic I started in 2006 has come around again. Sorry I did not see it earlier to give an immediate response. ...(I thought we were supposed to get an auto-email to say that something was posted??? .....hmmm maybe I missed it).

X_Factor, when my crankshaft and camshaft sensors went bad, it caused the engine to cut-off while driving. In the earlies, I was able to restart again and everything was good. Later on it occurred more frequently. I did get engine light coming on when this occurred.

If you are burning mundo fuel, you may want to shift your attention to your oxygen sensor, MAF sensor, and other sensors on your fuel circuit, spark plugs etc...

Good Luck...