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Water temp sensor.


Blob1620

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Hey everyone,

 

there's a lot of literature about this on here but theres also a lot of contradiction. Has anyone successfully gotten their factory water temp gauge to work with the one wire sensor in an RB. I have a series 1 motor, but it didnt have a 1 wire sensor, just the ecu sensor. I purchased a 25080-89907 to fill the factory hole, but was this the incorrect resistance range to accomplish what I'm trying to do. apparently theres another identical size but different range sensor as well. which is the correct one?

 

Thanks for the help!

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Hey everyone,

 

there's a lot of literature about this on here but theres also a lot of contradiction. Has anyone successfully gotten their factory water temp gauge to work with the one wire sensor in an RB. I have a series 1 motor, but it didnt have a 1 wire sensor, just the ecu sensor. I purchased a 25080-89907 to fill the factory hole, but was this the incorrect resistance range to accomplish what I'm trying to do. apparently theres another identical size but different range sensor as well. which is the correct one?

 

Thanks for the help!

I listed the actual some resistance ranges required to move the Z gauge the correct amount. I too put in a generic brand sensor similar to the above (for a KA engine I believe) and had it read low. Then I checked the Z32 service manual (which I thought was the same sensor as the KA one) and it showed that the range should match up.

Upon looking up the Z32 FSM, i found it should read:

70-90ohms @ 60*C (140*F)

21-24ohms @ 100*C (212*F).

 

 

 

 

Stock 260z gauge reads roughly 130-140* at the 80 ohms I measured. 

 

I'd say the sensor should read about 30-40 ohms at operating temperature. You could check that with a voltmeter. 

Next i'm going to grab a stock sensor out of a junkyard car, or at least measure a few beside each other to see which has even the closest room temperature resistance.

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For a while I ran the factory sensor in a maxima adapter (junkyard special). Just splice the adapter into the stock upper radiator hose, plug in the factory sensor and you're good with the factory gauge.

 

My reasoning was I have a wiring specialties harness (way too expensive for what it is but I was young and didn't know then what I know now) and it's stripped of everything non-essential. However, it has no provision for a temp gauge output yet uses the factory 1 wire sensor in the harness along with the 2 wire for the ECU. So they're using it for something but I'm not sure what. 

 

I have since switched gauges and running my autometer sender in an upper coolant neck spacer (much like the ones readily available for the SR20) but I digress. 

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I have a series 1 rb, I used this information from wiring thread, Water temp gauge - Use S13 or R32 Skyline sensor Part No 25080-89903 if you have a motor from an R32 then it already has the correct sensor. Different part number than in your first post. I screwed the sensor into the head with some liquid gasket and then plugged the factory temp gauge sensing wire into the sensor.

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  • 2 weeks later...

So it looks like the one i had already was the right resistance range, and my wiring was the problem. These pictures were taken at 210deg when my fan switch is supposed to come on, and at 175 when its supposed to turn off. Looks damn close to me.

post-47983-0-63048900-1440464638_thumb.jpg

post-47983-0-53574200-1440464668_thumb.jpg

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Blob,

 

My temp level needle has more swing than your images are showing while I am sure our engines are cycling through similar temps. I am using the BMW dual fan thermostatic switch to control my cooling fans. It turns the high fan off around 200 and the low fan around 180. When you have the time you might want to try threading in the other level sensor (if you have it) to see if it will give you more resolution.

 

The important part is that your fans are coming on when they should be and cooling the motor. Are you able to monitor temp through the harness, via Nissan Consult or a stand alone? You can use that to ensure your fans turn on and off when advertised.

 

I would recommend checking to make sure that the temp level sensor will indicate when temps go too high. You want to know if your fans take a dump and you are running hot. If you dare, unplug your fans and run your engine until you see the needle go up towards the right, then just plug the fans back in or turn the car off. 

 

Hope you can drive her soon, I am stuck in pinion angle hell.

 

Bill 

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I don't have any sort of way to monitor the ecu temp reading unfortunately. extra tools like that needed to communicate with my stock ecu have been over my minuscule budget for the moment. I've been driving it about two weeks now. going to drop the break in oil this weekend and put in something a bit less thin (look at my oil pressure, that's at 3k rpm)

 

My fan switch is the universal Summit Racing relay kit, and and fan. instrumentation has been coming along one gauge at a time. I verified my proper fan operation before driving it using a IR gun. The car is really running nicely the more it breaks in. i think the previous owner of the RB must have beaten on it (thus it needing rebuild) because the transmission shifts like a farm tractor. Gotta match rev on up shifts now and again. Ether way, building the plane as i fly it, and really happy to be on the road with it :) after break in, up goes the boost as well. :) 

 

Included a picture of two weekends ago, taking a drive in the mountains. 

post-47983-0-63814700-1440516688_thumb.jpg

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Blog,

 

Sounds like its up and running well. My 2nd gear synchro crunched bad when I first got the motor/trans. I mixed a quart of GM synchromess in with the MT 90 and that helped.

 

Bill

 

Good suggestion. I'm still sponsored by LiquiMoly so I went with their synthetic gear oil and Extreme Oil/Gear additive. I'm running LM GT1 10w-50 in the engine too. Something tells me the thinner flowing nature of their products may just be causing it to shift a little clunky. I've noticed 90's gearboxes tend to like oil as thick as honey haha.

 

I had a 1970 Mustang that I did a tremec T-5 swap in, same thing, didnt shift right till I put really thick oil in it. so..... 

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