Temperature Sensors

[GQAndrew]

Hi Guys,

Need a bit of clarification. On the thermostat housing, there are 2 temperature type sensors. The Gregorys manual states that one is a "Coolant Temperature Sensor" and the other is the "Temp Gauge Sender". So from what I can understand, the 'Coolant Temperature Sensor' is used to determine if the glow plugs should come on, and the "Temp Gauge Sender" controls the Temp Guage. Is this correct?

I believe I need to replace both. Firstly the "Temp Guage Sender". My temp guage seems to be a little intermittent, basically it is always below 1/4, but then if I speed up tp over 110 , it goes up to 1/2 quickly, then as soon as i slow down, drops to 1/4 instantly, which I find a little strange, where should it sit normally??

Secondly, the "Coolant Temperature Sensor" which I believe is connected to the Glow Plug Controller. My Glow plug light stays on for the maximum time every time I start the car, even after driving at operating temp, I can turn off the ignition, and it will do maximum glow plug again. I will test the Sensor on the weekend as instructed in the manual, but there appears to be no test for the gauge sender.

Also, do the sensors come with the bolts that go into the housing, or just from the plug onwards??


Thanks

Andrew

[bazzle]

Temp gauge sounds normal for "an engine with a dirty radiator fins"

The fact it goes down when using less power normally indicates cooling system inadequacy.

Nothing wrong with 1/2 reading either. Also some go to 2/3rds on hot days or pulling really long steep grades but come down when on the flat again.

Also wise to replace thermostat with genuine on a high mileage motor.

Bazzle

[GQAndrew]

Temp gauge sounds normal for "an engine with a dirty radiator fins"

Do you mean the outside of the radiator would be clogged up with dirt, insects etc?

The fact it goes down when using less power normally indicates cooling system inadequacy.

So at higher revs it cannot cool quick enough? What can I do to make the system more adequate, clean the radiator??

Nothing wrong with 1/2 reading either. Also some go to 2/3rds on hot days or pulling really long steep grades but come down when on the flat again.
Also wise to replace thermostat with genuine on a high mileage motor.
Bazzle

So what exactly would normal operating temp read? 1/4 and under?? Its just in other cars ive seen, the gauge reads operating temp within a few minutes, and doesn't move at all, whereas mine sometimes doesn't even get to 1/4, and drops pretty quickly when idling.

Sender is $59 from Nissan, and I checked mine and looks like it could be losing connection, will clean it up this weekend. May buy the new one if I do not resolve the problem. May also take out the thermostat and test it, is it possible that it could be stuck half open permanently or something?

Resolved the Glow Plug issue, seems me messing around trying to pull open the connection somehow refixed the connection, and now it is working like before. I think it stuffed up when I did my last oil change, so maybe I unclipped it slightly when I was pouring the oil in?


Thanks for the info

[Leprecaun]

In my diesel its normal except under heavy loads and prolonged climbing that the temp goes over half, otherwise its just under ½ on the guage.