View Full Version : Overheating problem almost solved

09-01-2004, 06:28 PM
Hey LBC owners,
About a month ago I posted about my TR6 overheating. Over the last few weeks I've been messing with the car. Heres what happened if you don't remember. I was driving home and it started to look like it was overheating on the gauge. Since then I've replaced the thermostat, sending unit, and temp. gauge. The replacement gauge is reading the same as the one I took out. After many times of warming the car up and taking it on a few drives I've measured how hot the fluid in the radiator was. I haven't got a reading over 160 degrees yet. I'm starting to think that it has to be something in the wiring loom that has either been cut or stripped. No Idea what could be wrong. Any ideas? Could my voltage stabilizer on the back of my speedo have gone bad? I've looked under the dash and everything seems to be hooked up properly. I don't really have anymore ideas except to make a new wire to run from the fuse block to my speedo and then to the temp. gauge. good or bad idea? I know that the temp. and fuel gauge are hooked up through the voltage stabilizer and my fuel gauge seems to be pretty close to right. Any ideas on what to do next?
73 TR6

09-01-2004, 07:07 PM
Overheating in a TR6 can definately be an enigma. Have you made any changes to the car at all: hotter plugs? exhausts? timing? Unless something is systemically wrong with the car, you might try colder plugs, WATER WETTER, flushing your cooling system or even having your radiator cored. I had mine redone into a 4-core radiator for not a whole lot of money. Every little thing helps. Although many people will enjoy a cool running TR6, my experience has been that the little boogers will run warmer than not, expecially in traffic.


09-01-2004, 08:22 PM
Eric my vote is a bad sensor in the thermostat housing, or possibly an air bubble trapped there......
MD(mad dog)

09-01-2004, 11:54 PM
Aloha Eric,

My TR3 has an electric Temperature gauge from a TR4. When I first got the car I was concerned about over heating because a road speed the gauge would read very hot. I checked the same things you have and I began to think the gauge was wrong. After some research, I learned I needed a voltage stabilizer in the circuit. The original TR3 temperature gauge is a capillary tube type gauge, so the car didn't have the voltage stabilizer installed. I added the approx $15 part and gauge worked correctly. It provides a steady 10V to the gauge. If your voltage stabilizer has failed, at road speed, increased voltage will cause higher and inaccurate temperature reading. The inaccurate temperature reading will rapidly rise with engine revs and drop rapidly at idle, going from hot to cool in a mater of seconds. The voltage stabilizer may be bad.

Safety Fast,

90 XJ-S
09-02-2004, 12:08 AM
Mad Dog has the call on this.
Replace your sender and /ubbthreads/images/graemlins/driving.gif


Rick O.
09-02-2004, 10:42 AM
Remove the wire at the coolant temp sensor and ground it; your temp gauge should move to full hot. If not, replace the sensor.

Also, 160 degree coolant is a bit cool for a warmed up engine. For best performance and fuel economy, you should be closer to 180 degrees with a hotter t-stat. This higher temp also ensures blowby combustion water is evaporated from your oil.