So where I live it tends to be very cold. It's about - 20 degrees Celsius. But anyways my car doesn't seem to heat up completely. The only time the needle has hit the middle of the gauge is after sitting there idling with no heat on. My coolant level is good to. Could this be a thermostat problem ? Or could it be because the weather causing the car too cool down to much ?

 

Looks pretty normal to me... it is always between the 2nd and 3rd line on my car...

CEO

 

Thermostat. It's stuck open not allowing the coolant to get to normal operating temperature. Replace that and you will be back to normal...get some gas too!

 

What is your normal temp needle at? It should be somewhere between the 2nd and 3rd line.

CEO

 

I noticed that my recently acquired GS400's needle sits at the same spot. Will replace the thermostat and see what happens.

 

Normal should be midway on the gauge, like the 9 o'clock position.

I would look at the thermostat first. You can take it out and boil it and measure the water temp it opens at. Make sure to refill coolant with proper Toyota red fluid.

 

Change your thermostat & flush your coolant system.

 

Mine sits dead on in the middle and stays there when in normal op temp. I had the same problem the OP had until I replaced the t-stat. That needle should never move from the middle (9 o'clock position) when in normal operating temp. Gas mileage will suffer because the engine is in open loop longer trying to warm up.

 

Has anyone upgraded to a lower temp t-stat?

 

180 degree is what is recommended so I just went with that.i say you replace the thermostat and that will more likely then not get you back to normal operating temp.

 

Knowing what I know on oil viscosity and relationship to temp, I would leave the stock thermostat in. The difference isn't going to be much if anything, the biggest improvement would be if you could keep it from getting over thermostat temp on a hot day, it will drop performance then as the ECU will pull out ignition timing.

 

Most def. thermostat