temp gauge

[jfet]

Where in tha heck is the temperature sender thinggy to the gauge on the 1.6 engine I cant find it anywhere?

[TTriX]

if it is a 16de and you are looking for the coolant temperature sensor...it is in the radiator mounted in the side with wires going to it...it has a hex shaped head for removal and you can change it your self...the rad drain plug is below it and it has a butterfly(wing nut) style top to it.
T
looks kinda like an O2 sensor but on the side of the rad.

[Lonx]

On the CA engines, the water temp sensor on the radiator (exit side) is for the thermofan switch only. The one which the ECU uses is located on the exit of the engine block. Look between the first injector and where the top radiator hose connects to the engine.

[roshfe]

On my CA18DE, I was having trouble with the connection at the Water Temperature sensor (RTD mounted to the engine near the coolant exit by the thermostat). The conenction was bad and was giving either no connection or a high resistance (depending on the day) For a while, it was completely disconected and yet the engine temperature gauge on the dash was still giving me a reading.

From what I can tell, the temp sensor near the thermostat goes straight to the ECU. Is there another sensor somewhere that goes to the instrument cluster?

[TTriX]

sorry...i didnt realize that is what he was looking for...his terminology is as bad as mine-hehe
T

[Lonx]

The dash gauge receives its signal from the ECU, which gets it from the sensor near the thermostat.

The reason you still had the gauge working with the sensor unplugged is because without this sensor input, the ECU defaults back to two temperature values. One is about 20 degrees C and the other is 80 degrees C. Problem is once your engine gets above 80 degrees, the ECU won't inject enough fuel for the optimum mixture and it will run lean (in open-loop mode, or when accelerating). Resulting in a hot engine, possible pinging, loss of power & some loss in drivability (sluggish, stuttery acceleration). Same problem occurs when the engine is warming up, but the ECU hasn't decided to default to 80 degrees yet... so the engine temp is say 30 - 50 degrees and the ECU thinks its only 20 or something like that.

[jfet]

Thanx for the help I found it. Now all ive got to do is get a patch of decent weather.

christoph

[turbo18exa]

there are 2 senders one is for the computer has a plug like an injector with 2 wires from memory they are yellow and yellow/green stripe(only from memory) this sender sends info to computer and is all this one does it has nothing to do with guage at all i should know i have no stock computer

The other sender is a one wire sender has a single plug it is for the guage located on inlet manifold near other sensor this one is the one which the guage inside the car uses basically it is a resistor which varies with heat

if u want to test your guage get a variable resistor and earth one side and plug other side to sender wire then vary the resistance to the specs in the manual

To test the ecu sensor you have to check the resistance against temp specs are in manual if it is stuffed then the car will either run rich if its readding cold or lean if its reading hot but that is only because the resistance value in the ssensor has change and nothing to do with the computer

[roshfe]

The sensor that turbo18 is talking about is refered to as the Thermal Transmitter and the wiring can be found on page EL-57 of the shop manual ( click here to view (http://pulsarexa.netfirms.com/F_Graphic1_page522.htm) )

I found it last night while looking for something else!

Hope that helps some.

RoShFè :stikdance'

[Lonx]

Ahhh, stupid Lonx! Didn't know of this thermal resistor, so therefore the car actually has 3 different temp sensors all for different purposes. Bloody silly old nissan engineers! Cheers for posting that guys,

[roshfe]

So there is 3?
[list=1]
Water/Coolant Temperature Sensor (RTD) - talks to the ECU to adjust fuel mix
Thermal Transmitter (RTD) - talks to the dashboard Gauge
Rad Temp Sensor (SWITCH?) - talks to the thermo-fan (RAD)
[/list=1]

:frustrate Just tryin' to understand it all! :3eye:

Thx

RoShFè

[turbo18exa]

yep thats pretty much it

[oldskool]

So does anyone know where the "Thermal Transmitter" is? I really need to check it. My temp guage hasnt worked for about three months and I also have very sluggish/stuttery accelleration at around the 3000-4000 rev range, especially when the car is warm.

[roshfe]

Hey

As per the shop manual, the Thermal Transmitter is near the top of the engine just behind (closer to the firewall than) the timing belt. If you have the shop manual, the diagram is on page EL-84. The page is on-line at http://pulsarexa.netfirms.com/F_Graphic1_page549.htm
but this is one of the pages that is hard to read. The connector that you are looking for is 4E. I think that it is right above the Water Temp Sensor (14E) which is near the the thermostat.

Hope that helps

RoShFè

:bounce:

[Lonx]

If you have trouble finding it, from the wiring diagram it looks like the gauge sensor comes off the same part of the loom as the oil pressure sender, so trace it from there.

The turbofan you mentioned is just a thermo fan (or thermostatic :D ), all exa's have these.... the extra smaller fan on some models is for those which came with air conditioning from the factory.