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amo1dun

Engine Coolant Temperature Sensor

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89 Pathfinder 4WD Auto 4x4

Truck hard starts when cold, stalls, eats ridiculous fuel...

 

Im getting a code 13 ect sensor. Is it really buried behind the t belt cover or is their a different way?

Is their a way to test this thru the connector because i think... the connector is right in front of the ab valve if im not mistaken or do i actually have to take the sensor out? Does anyone know what it is supposed to read? Also,is this code 13 the cylinder head temperature sensor or what...anyone who can help clarify this for me? All tips tricks responses are greatly appreciated..!! :)

 

 

Thanks

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the engine temp sensor isn't really buried. you can see it poking out of the intake manifold about 5 inches back from the timing belt. And , yes, you can check it without taking it out.

 

Step one: find it.

step two: take off the lead

stepconnect c: connect a multi meter to the connector and the hex nut and check resistance----70-90+ ohms

4 : warm up engine and repeat. resistance should be between 20 and 40

 

if all is good then its the wire.

 

if thats fine...it's the cyl.head temp sensor. in which case, repeat the steps.

 

If this sensor(s)fauty it will cause you to eat gas as the ECCS won't go into "closed loop" mode, and run REALLY RICH all the time.But, it shouldn't cause stalling. That'd be something else, probably on the throttle body.

 

Hard starting in the cold-----It;s a silly question but when's the last time you changed your oil?

Edited by LittleReD89

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The sensor will cause stalling, dumping so much fuel into the engine that it floods it completely. I've had that sensor go out intermittently on my old '87, it would barely run and die. Some days it would be fine and then all of a sudden it would go nuts. It was showing 120 ohms of resistance.

 

 

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My 89 seems to have 2?

one just behind the coolant neck and another one just behind the throttle body. my spare manifold does not have the second one.

Is it possible the the CA models had 2 coolant sensors, or is 1 an intake temp sensor for a CA model? It has 2 REALLY SKINNY wires coming out of it?

 

Upon closer inspection it seems this mystery sensor goes directly into the EGR passage so I'm guessing CA models monitored egr temps?

Edited by MY1PATH

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Thank for the responses guys...Just so Im clear are these the sensors?....

 

th_DSCN0397.jpg Engine coolant temp sensor on top(sending unit for gauge)

 

th_DSCN0402.jpg Cylinder Head Temp Sensor thats buried

 

How do I get to the cylinder head temp sensor..? Do I really have to take the tbelt cover off or can u sneak in by the water pump or from the top with a swivel and extension...What do you guys think, any hints?

 

Thanks for reponding guys

Thanks

Edited by amo1dun
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the one for the ecu has two wires with a f/i injector style connector, the one for the gauge is a single wire.

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th_DSCN0402.jpg Cylinder Head Temp Sensor thats buried

 

How do I get to the cylinder head temp sensor..? Do I really have to take the tbelt cover off or can u sneak in by the water pump or from the top with a swivel and extension...What do you guys think, any hints?

I was looking @ this today, my truck has been getting ~12mpg and poping exhuast since I got back from cali. It smells a little rich and last week it threw code 13 but has not done so again...

ANyway a shop chaged kingman 5.5 hrs of labor for his old pathy because it was underneath the intake manifold... I am hoping that if I take off the AC idler backet and maybe a coolant hose or 2 I will be able to sneak in there and change it.(reaching thru the gaps in the timing cover)

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I was looking @ this today, my truck has been getting ~12mpg and poping exhuast since I got back from cali. It smells a little rich and last week it threw code 13 but has not done so again...

ANyway a shop chaged kingman 5.5 hrs of labor for his old pathy because it was underneath the intake manifold... I am hoping that if I take off the AC idler backet and maybe a coolant hose or 2 I will be able to sneak in there and change it.(reaching thru the gaps in the timing cover)

 

It seems awfully tight in their man...I can get my maglite to touch the sensor thru the front, but I think the angle of the sensor will make it tough to get a socket in their without removing the cover....5 1/2 hours labor at the shop to change...? :crazy:

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It seems awfully tight in their man...I can get my maglite to touch the sensor thru the front, but I think the angle of the sensor will make it tough to get a socket in their without removing the cover....5 1/2 hours labor at the shop to change...? crazy.gif

 

 

well If I can't I'll just wait till I do my cams, I'll have all the covers off then. I still don't think the manifold should have to come off.

Edited by MY1PATH

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It seems awfully tight in their man...I can get my maglite to touch the sensor thru the front, but I think the angle of the sensor will make it tough to get a socket in their without removing the cover....5 1/2 hours labor at the shop to change...? crazy.gif

 

 

I just got it! took the Idler pulley bracket off and use a needle nose and tiny screw driver to unclip the wire lead. then I slid a 19mm mid length 12point in there. A 6 point won't clear the plug a regular 19mm will not reach past the plug and a deep 19mm will hang up on the timing cover. If you only have a deep well you can cut it down till it just clears the cover. Kingman gont raped on his! 5.5 hrs of labor Ha! try an hour tops.

 

My connectors were coroded and the old sensor fell apart as soon as I got it out. Clean contancts & new sensor I'm hoping for the best now.

 

 

OH and It measures your Cyl head temps WITHOUT being Imersed in coolant so you don't have to drain anything and feel stupid like I did.

alos using 3/8" drive w/ extension instead of 1/2" drive will make clearing the timing cover allot easier

Edited by MY1PATH

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Nice, try taking a picture to post and we will pin this topic. Price of a socket and a sensor instead of having to remove everything. :clap:

 

B

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Nice, try taking a picture to post and we will pin this topic. Price of a socket and a sensor instead of having to remove everything. clap.gif

 

B

 

 

Amo1dun can you try and take pix when you do this? It completely spaced my mind. Its actaully pretty easy to locate onece the Idler backet is out of the way. shine a light in few differant angles but getting good photos in the tight space may be challenging.

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I just got it! took the Idler pulley bracket off and use a needle nose and tiny screw driver to unclip the wire lead. then I slid a 19mm mid length 12point in there. A 6 point won't clear the plug a regular 19mm will not reach past the plug and a deep 19mm will hang up on the timing cover. If you only have a deep well you can cut it down till it just clears the cover. Kingman gont raped on his! 5.5 hrs of labor Ha! try an hour tops.

 

My connectors were coroded and the old sensor fell apart as soon as I got it out. Clean contancts & new sensor I'm hoping for the best now.

 

 

OH and It measures your Cyl head temps WITHOUT being Imersed in coolant so you don't have to drain anything and feel stupid like I did.

alos using 3/8" drive w/ extension instead of 1/2" drive will make clearing the timing cover allot easier

 

A lot of techs at my shop have started using 1/4" stuff for clearance issues.

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I just got it! took the Idler pulley bracket off and use a needle nose and tiny screw driver to unclip the wire lead. then I slid a 19mm mid length 12point in there. A 6 point won't clear the plug a regular 19mm will not reach past the plug and a deep 19mm will hang up on the timing cover. If you only have a deep well you can cut it down till it just clears the cover. Kingman gont raped on his! 5.5 hrs of labor Ha! try an hour tops.

 

My connectors were coroded and the old sensor fell apart as soon as I got it out. Clean contancts & new sensor I'm hoping for the best now.

 

 

OH and It measures your Cyl head temps WITHOUT being Imersed in coolant so you don't have to drain anything and feel stupid like I did.

alos using 3/8" drive w/ extension instead of 1/2" drive will make clearing the timing cover allot easier

 

Great Job!! :clap:

 

How do you remove the idler pulley bracket? The belt and idler pulley have to be removed to get to the bracket, correct? Can you explain how you did that?

 

" so you don't have to drain anything and feel stupid like I did." .... Imagine how I feel.... :headwall:

 

PS- The part name when ordering is "Engine Coolant Temperature Sensor" or "Water Temperature Sensor" and should have 2 leads in the connector...right?

 

I will definitely take pics.

Edited by amo1dun

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Great Job!! clap.gif

 

How do you remove the idler pulley bracket? The belt and idler pulley have to be removed to get to the bracket, correct? Can you explain how you did that?

losten the pulley with a 14mm wrench. (1 or 2 turns is all you need) then back off the pulley tensioner blolt just above the pulley with a 12mm untill the pulley slides down far enough to slip the belt off Just let it hang there unless u plan on driving w/ it off. The bracket will now come off with 3 bolts; 1 near the AC pump one on the opposite end of the bracket and one Hiding just below the pulley (all 12mm)

 

when you put the belt back on the tesion should be so that you can push the belt aprox 1" with moderate effort then you can snug the pulley nut.

PS- The part name when ordering is "Engine Coolant Temperature Sensor" or "Water Temperature Sensor" and should have 2 leads in the connector...right?

 

Most places with have both sensors (guage & ecu) under the same listing the one for the ECU is technically a Cyl Head temp sensor (on vg30i) but you will likely not find one by that name. SO yes you will have to varify that it has a 2 lead plug before buying.

 

Rock Auto denotes them seprately as "sender" and "sensor" the latter being the one you want.

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losten the pulley with a 14mm wrench. (1 or 2 turns is all you need) then back off the pulley tensioner blolt just above the pulley with a 12mm untill the pulley slides down far enough to slip the belt off Just let it hang there unless u plan on driving w/ it off. The bracket will now come off with 3 bolts; 1 near the AC pump one on the opposite end of the bracket and one Hiding just below the pulley (all 12mm)

 

when you put the belt back on the tesion should be so that you can push the belt aprox 1" with moderate effort then you can snug the pulley nut.

 

 

Most places with have both sensors (guage & ecu) under the same listing the one for the ECU is technically a Cyl Head temp sensor (on vg30i) but you will likely not find one by that name. SO yes you will have to varify that it has a 2 lead plug before buying.

 

Rock Auto denotes them seprately as "sender" and "sensor" the latter being the one you want.

 

Hey I really appreciate it My1PATH and everyone that responded...I knew you guys would be able to help. I will do this in the next week and will take pics of every step.

Edited by amo1dun

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I got it! Cylinder Head Temp Sensor is all good! without having to take off the tbelt cover!

 

Removed pulley bracket(Thanks to MY1PATH) See his post above for steps to remove its very easy. Using a maglite, locate the sensor behind the cover. Unplug the connector(Their is a metal clip holding the connector on) Once off, I cut 1/2" off of a 6point 3/8 13/16 spark plug socket and pulled the rubber piece out of the socket and it fit perfect over the connector....Put the socket on first.(worked it behind the cover w/ my fingers and lined the points up with the nut) then used a 6" 3/8 extension and 3/8 ratchet. Used this just to loosen the sensor( until it hit the back of the cover)then it came out by hand. Putting the new 1 in...Hand tightened the sensor and used needlenose pliers until it was in far enough to work the socket back on, then the extension. Tightened it up, plugged the connector back in, Put the belt and bracket back on and thats it....No more code 13, code 55 all good! Running alot better! :beer:

 

th_DSCN0415.jpg

(Pulley bracket off, Sensor is behind the curve in the cover in the pic...follow that harness next to the cap down)

 

th_DSCN0440.jpg

(Temp Sensor removed)

 

th_DSCN0438.jpg

( You can see how close it is to the cover...Hand tighten until you can get the socket back on)

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Nice!! Both the work and the write up witrh pictures!! Thanks to you and My1Path. :clap:

 

I'll go ahead and pin this in the Garage/How To section now... :D

 

B

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My 94 has 2 sensors right near the top front of the engine, very easy to get at, I guess they changed the location from what is described in this thread?

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My 94 has 2 sensors right near the top front of the engine, very easy to get at, I guess they changed the location from what is described in this thread?

 

 

yes,the MPFI pathfinders have the guage and the ecu sensors in the coolant neck. I belive the threaded hole(does not enter the waterjacket) is still there on the newer vg's so if you wanted the ecu to read the cyl head temp you could prolly move it there.

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Okay, great thread. But I have looked all over the place and have not came up with a viable solution. I am sure people have done this...but how?

 

My question is simple.

 

I am wanting to put an aftermarket coolant temp gauge in, because I simply do not trust my factory...

 

Where was it hooked, and how was it effectively done? What I mean is none of the SAE fittings included in the mechanical temp sender kits will work, and too many adapters, and T's will move the sensor lead away from the place it needs to be...

 

Any thoughts?

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Where was it hooked, and how was it effectively done? What I mean is none of the SAE fittings included in the mechanical temp sender kits will work, and too many adapters, and T's will move the sensor lead away from the place it needs to be...

 

Any thoughts?

 

Get a sensor pipe, cut about 0.75" out of your upper hose where you wnat to locate it and splice it in.

 

It will literally be a pipe with a threaded hole in the side you could polly grab a nut and have an exhaust shop make you one for $20 or less.

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Interesting...That actually looks simple enough to make...Thanks!

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The sensor will cause stalling, dumping so much fuel into the engine that it floods it completely. I've had that sensor go out intermittently on my old '87, it would barely run and die. Some days it would be fine and then all of a sudden it would go nuts. It was showing 120 ohms of resistance.

So this can keep dumping fuel like clogged injectors do huh?...I've now gotten a 13 on the ecu and was thinking my injectors were clogged again...I just replaced the fuel line and filter and wanted to check the ecu one more time before I pulled the injectors back out. Is 13 a engine coolant temp sensor on a 87? I know some are different, like the 43 injector code was.

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