coolant temps and temp sensor location

[f s t caz]

I recently installed a cooltant temp gauge because i wasn't satisfied with the factory gauge but i'm not satisfied with what my new gauge is telling me either.

1st - the temp sensor is installed in a metal pipe/bung that i found in a s13 in the junk yard. It's a factory piece apparently (can't remember back to having a stock KA anymore) that was installed in the lower radiator hose. For my application, it's been installed on the top hose. I had to buy a brass fitting, drill it out and tap it to make the autometer sensor fit. I'd say less than a cm of the probe sits beyond the fitting in the pipe.

2nd - i have fully opperational heat before the gauge ever registers past 100*F. It takes my car about 2-3 minutes idling to warm up to the point where the factory gauge is at half and the heat is blowing hot. Every other nissan around me takes atleast 5 min or so.

3rd - The gauge never goes above 110* sitting, never above 150* driving, stuck in traffic, etc. The coolant warms up while driving, makes its way to 150 and never goes higher, doesn't go lower whether I'm on the interstate at 65mph or driving thru town at 35

4th - FSM says my thermostat wont even open until 180*F and I never get above 150* (according to the autometer). Usually, shortly after the factory gauge reads middle, i can see the coolant start circulating in the radiator so I know the t-stat is actually opening.

5th - I've been splitting hoses, one at a time, for over a month now. I thought perhaps it was just their time as they are original coolant lines and would be about 17 years old by now, but its getting old and i'm running out of luck when it comes to not over heating and being able to make it home before anything bad happens. I need that temp gauge to work to find out if my efan is doing its job and to make sure i'm not running the engine too hot.

Do i have the sensor in the wrong spot? Is it not in there deep enough? I've seen pictures ( i think ) of other people w/ bungs and temp sensors in the same location. what temps are you guys running? Thanks for the help.

Chris

[UMS_CA18DET]

How close is the tube to the inlet port? The optimal location is to get the sensor as close to the head as possible. Thats why the stock ones are next to the head. The further the autometer sensor is the cooler you'll see the gauge. Also it can be a bad sensor and bad gauge. Also what material is that pipe made of could be that it might not be a good enough ground for the sensor, since the sensor is actually grounded on whatever its threaded to.

To test the sensor and gauge heat up the sensor via lighter, heatgun etc etc and ground the sensor on any part of the motor or chassis and see if the gauge responds quickly.

[f s t caz]

the sensor is grounded to the pipe? that could be a problem then. here's how its installed

[tecnic1]

yeah...it grounds through the threads. just tack a screw to that pipe and use that to ground...

[UMS_CA18DET]

From the looks of it, its too far away from the Head.

Did you try testing the gauge and sensor the way I told you to?

[f s t caz]

i ran a ground wire and installed a loop around the sensor and the gauge works now. guess i should have read more carefully. now its running at ~190*-200*

[capwred]

going try thqt myself i guess thats why mine dosent work to.i hooked it up as you did to begin with.

thanks for the info also.