What is the average temp of the 1987 NA. My temp will not go higher then the the first line. I switch it with another temp sending unit and it still did not change anything.

 

Do you mean you changed the thermostat? If so did you use a Mazda OEM thermostat? Others who have tried using aftermarket tstats such as Stant have not come up with good results.

 

no the sensor that sends the temp to the guage.

Do you thing the therostat is maybe bad?

 

Thermostat COULD be bad. The engine may be just running that cold.

But the stock gauges are not known for reliability.

 

Is there any sign that can tell the thermstat is bad

 

Running too hot or too cold.

Have you cracked it open before? Is it possibly you're not running any thermostat at all?

As I said before the stock gauges aren't exactly reliable, so it might be just the gauge itself.

 

I will look at it tonight, Thanks for the help