# Temp Sensor abnormally low?



## cjserio (Mar 18, 2008)

My engine temperature gauge just barely moves up to maybe 1/5th of the full scale when the engine is completely warmed up. Does this seem abnormally low to anyone else?

When i first got the truck a few month ago, it didn't move at all and my mechanic installed a new one.

If this is reading low, can this be causing any performance problems or is it merely a reading for the driver to see? What could be causing such a low reading? Where can i find this sensor to check it myself?


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## cjserio (Mar 18, 2008)

I forgot to mention i have 1994 4x4 with a KA24E engine.


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## zanegrey (Dec 5, 2005)

check fan clutch..


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## Humanure (Feb 15, 2007)

Was the thermostat changed recently? I tried a non-oem (aftermarket) thermostat in my 93 ka24e, and it sucked. Like the symptom you mention, my temp would also read low. I immediately bought an oem one from my local dealer, replaced the faulty one and that solved my problem.


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## cjserio (Mar 18, 2008)

zanegrey said:


> check fan clutch..


What are you thinking that my fan is always running? Come to think of it...It does run immediately after i start it and i can't remember ever seeing it not run...Not sure if that's normal or not.


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## cjserio (Mar 18, 2008)

Humanure said:


> Was the thermostat changed recently? I tried a non-oem (aftermarket) thermostat in my 93 ka24e, and it sucked. Like the symptom you mention, my temp would also read low. I immediately bought an oem one from my local dealer, replaced the faulty one and that solved my problem.


Yes it was recently changed. As i said, it didn't move at all until my mechanic installed a new one but i'm almost certain he got it from the Nissan dealer.

Does anyone know if this can effect performance?


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## Humanure (Feb 15, 2007)

Almost certain? Next time you talk to your mechanic, ask him what he used. As for performance, I can't remember it affecting the performance but it certainly affected the heater. I wasn't satisfied with the luke warm heat and longer time it took to produce it.


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## cjserio (Mar 18, 2008)

I spoke to my mechanic and it is a genuine Nissan part...I'm not sure what could be wrong...The heat comes out at a reasonable temperature...Maybe it's the gauge itself?


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## NelsonCnty (Jan 7, 2008)

I had the same problem. Turned out to be the water temp sending unit, which is basically an aquastat that sends info to the gauge. It's easy to test: disconnect the wire that clips onto the sending unit, run a jumper from that wire to battery positive, and turn on your ignition: the guage will pin all the way hot if it's the sending unit. otherwise, may be a bad connection between the unit and the temp gauge. this test is detailed in the Haynes, but everything is right there and easy. $10 part.


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## cjserio (Mar 18, 2008)

I misspoke...The mechanic did not touch the thermostat, he changed the sending unit...my original complaint was that the gauge didn't move at all...now he installed a nissan sending unit and the gauge moves but when the engine is fully warmed up, it's only up a small fraction of the whole scale.

If i'm correct, the sending unit just screws down into the aluminum channel that's fed by the top radiator hose? It looks like a shiny gold nut with a connector going to it?


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## NelsonCnty (Jan 7, 2008)

yeah, that's the sending unit.


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## pgsentra (Mar 2, 2007)

*Another bad coolant gauge reading - - -*

My 1995 XE 4x4 V6 is having the same temperature gauge issue. 

After many hours and lots of money put into temp sensors (both coolant temp sensors were replaced with OEM Nissan sensors), I'm back to square one, with the gauge needle not going more than about 1/5 of the way up, when hot. 

I've done the test for the gauge, and the needle spikes up to the hottest point, when the lead and ground are connected. So, I'm hoping that it is not the gauge, itself. 

Anybody know what the voltage going to the coolant temp sensor (the one that reports to the gauge) should be? I've measured mine, but I'm looking for other samples - my local Nissan dealership had no idea what this should be (if they don't know this, I'm not taking it to them to fix it). 

Also - anybody know what this truck's coolant temp should be under normal operating conditions? While I doubt that the vehicle is actually running cool, I'm looking for expected values here.


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## NelsonCnty (Jan 7, 2008)

when I first replaced my sending unit, I didn't notice much difference in the temp gauge reading. once I fixed my other problems (clogged EGR valve was the main culprit), the gauge seemed to be a little more responsive.

I was getting all sorts of error codes (which turned out to be wrong) before I traced the problem to the EGR. I still think my original sending unit was probably functioning just fine.

to answer part of your question, mine reads about 1/4 of the way up when the truck is good and hot. still lower than what I was used to with the minivan or the vw.


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## Gravehunter (Aug 19, 2008)

I just got my truck and havn't had time to check anything. But mine only goes up about 2 needles widths above the lowest mark on the guage. Basically barley even moves from cold to running down the road warm. 

I'll have to do some tests you guys mentioned in these posts.


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## CRNissan (Aug 29, 2008)

*New Temp Sending Unit Installed*

1997 2.4 Extended Cab 4x4. 

My temp gauge only read barely 1/16 at operating temperature. I replaced the the Temperature Sending Unit ($12.50 at NAPA, The Nissan dealer did not have one in stock and I would have to wait 1 week for the part to arrive). Now the temp gauge reads 3/8 at normal operating temperature.


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