Temp readings

[TominMO]

My original temp gauge in the blue car (stock motor) always read low, like just above the lower white line at the most. I installed another cluster, also non-tach, from my red car and it read about 40%, i.e. "normal", in the blue car. The red car this cluster came out of has the 1.6 DOHC, where it read normal too. I thought the normal reading while it was in the red car was because of the hotter-running motor. But it appears to be the gauge itself that reads hotter.

The third cluster I put in the blue car is the tach cluster, which also reads normal, not low. Soooo...do some temp gauges read low from the factory? I have heard other people talk about how their temp gauge reads low, and the reply is that these motors don't make enough heat to get the gauge up to normal. But this may be incorrect, since two temp gauges in non-tach clusters read very differently. The blue car is a 90 L with 159K, the red car a 91 L with 177K, and presumably they have their original clusters.

Maybe the one reading low is just defective from the factory, or just got worse as it got older.

[econoaddict]

I have heard other people talk about how their temp gauge reads low, and the reply is that these motors don't make enough heat to get the gauge up to normal.

I had the same issues when I first got my tiva and heard the same thing.

I verified actual engine temp with a temp gun and it was right where it should be when warm yet the gauge still said the car was cold.
I replaced the sender unit and the gauge itself, no change at all.
I then took apart every connector on that circuit and cleaned them and guess what........the gauge reads where it should

[TominMO]

I had the same issues when I first got my tiva and heard the same thing.

I verified actual engine temp with a temp gun and it was right where it should be when warm yet the gauge still said the car was cold.
I replaced the sender unit and the gauge itself, no change at all.
I then took apart every connector on that circuit and cleaned them and guess what........the gauge reads where it should

So, since the only difference in my case was which temp gauge I used, it seems that I could just clean the proper connector on the back of the instrument cluster, and it should work. I'll try it.

[fastiva1988]

Just a hunch... but when i got done rebuilding/swapping my festiva. my temp actually runs a bit hotter than it used to. I used to be just over the line now im at 40% also... coincidoince... i thought that the new t-stat may have had something to do with it.

[Mike McKown]

To test the gauge and the wiring circuit, you could try grounding the temp sender wire at the engine block. That should peg the gauge all the way hot. That is, if the gauge circuit works by grounding which many of them do.

[ejp2fast]

OEM thermostat should be dual stage..... all the McParts have single stage... therefore probably read low. dual stage Mazda (see sticky at the top of the repair section about needing more heat) is ideal. The gauge should be between 1/4 and 1/2 of the full Cold to Hot range for this dual stage.