Temp Gauge problem

[EA6BPilot]

While driving around last night, I noticed my temp gauge spiked all the way to the right. It was indicating normal until just before I pulled into my driveway. I shut the engine down, popped the hood, and couldn't tell anything different from normal. The coolant hose felt normal, the fluid levels were full, the fan was functioning, etc. Well, I decided to let it sit overnight and check it again. This morning, 12 hours after parking, the car still reads 250 degrees. The engine block and coolant hose are cool to the touch, so I know its just a false reading. The problem is, I don't know where to check now. Is there a temp sensor near/on the block somewhere? Is this a problem anyone else has seen? I am pretty sure that the cooling system itself (thermostat, radiator, pump, etc.) are functioning normal. Any help anyone can give is appreciated. Thanks.

Frank

 

[Tom F&L GoR]

According to the service manual, to test the gauge, you disconnect the sensor and it should read low. If you ground the pin 3 wire it should read high. Sounds like your wire between the gauge and the sensor has rubbed through and is shorting to ground? The sensor is in the thermostat housing.

 

[EA6BPilot]

Tom,

Can I get to the sensor without pulling off the intake? Sorry to bother you, but I unfortunately don't have a service manual. My bad......on my to do list. LOL Thanks for the help once again!

Frank

 

[Tom F&L GoR]

It's OK, I don't have a Gen 2!

The service manual image shows both the temp sensor for the gauge and the temp sensor for the ECU on the thermostat housing, which for you is in front, under the intake. Facing the thermostat housing, the gauge sensor is on your left (passenger side) and has a (single) violet wire with yellow tracer.

BUT there are many Gen 1 pictures in this Gen 2 manual, so since the thermostat for Gen 1 is in the rear and for Gen 2 is in front, look for the wire color. The ECU sensor is two wire, tan with black tracer and black with light blue.

You would be looking for where the violet/yellow wire rubbed through. Let me know what pages to scan if you get stuck.