My 2008 is250 car temperature gauge normally show around 1/3 of the gauge after engine warm up. Picture below show the car has ran for 30 minutes and the out side temperature is 66 degree. Is this normal? How does it show on your car? Thanks

 

Seems odd. You are correct. When the engine is cold and off for 2 hours or more, check the coolant level in the reservoir and at the radiator cap. At the pressure cap is should be full to the rim.

Suspect yours is low on coolant.

Normal operating temp usually has the needle at the 6:30 position. i.e. 6:00 o'clock being straight down.

 

I will check the coolant level and post back. Thanks, 2013FSport!

 

Mine is less than half way between C and H at normal operating temperature (perhaps a tick mark or two), but no way near as much as yours. I've owned my car since new, and it always read that way.

If you have a scan tool that reads coolant temperature, it would be interesting to know the actual value in degrees.

 

I just checked the coolant level in the reservoir and it is at the MIN line so I fill up the reservoir to the MAX line. Also the fluid level at the radiator cap is full.

 

Since it's running colder. I'd suspect a problem with the ECT switch, or a sticking open thermostat.

If you have a scan tool with live data. See what temperature it's showing. Another running colder than optimal temp. You'll be running rich for the time being. Do you notice a decrease in gas milage?

 

What is the ECT switch? Unfortunately I dont have a scan tool with live data. The gas miles is around 19 - 20 mpg 50/50 city/highway. I will replace the thermostat and the radiator cap first and post back the result. Thanks!

 

Engine Coolant Temperature sensor.

The engine will read nominal ~roughly between~ 172°F and 208°F. Somewhere in there. They basically normalized it so it doesn't hunt up and down or move all over so that Lexus people don't freak out.

Look for rodent droppings too. They have been know to chew on wires.... Also, inspect the water pump for leaks.

 

PS - if an OBDII scan tool seems out of reach technology wise, a $10 phone apps and a $30 Bluetooth OBDII Elm327 dongle will get you the info we need.

Let us know if you're interested.

 

I already have the OBDII ELM327 wifi scan tool and the inCarDoc app. I can read error codes and clear them when need. Thanks for the offering!

 

No water leaks from the pump and no sign of rodent from the engine bay. Thanks!

 

Look for the ECT sensor and watch what it does from startup.

I've never used that app. If it doesn't report the temp, download Torque Light or Torque Pro ($10), OBD Fusion ($10).

 

Great! Thanks for the information 2013FSport!
Below is the InCarDoc app, it shows the engine coolant temp as well, 77 degree while the car's engine is off (only turn on power for the OBDII to work). I can't start the car at the moment because I have removed the thermostat and waiting for the new part to come.

 

After replaced the thermostat and the radiator cap, the temp gauge showed a bit better but still not in the middle (picture below) after running for about 30 minutes. Is this normal? Can someone please compare on your car?
I would replace the Engine Coolant Temperature sensor too but its location difficult to reach so I am hesitate

 

No, in the above picture, that is where my needle resides 100% of the time AFTER reaching normal operating temp.