The temp gauge in my car goes up when my car is idle,it goes down when i rev it or drive it around.any idea?

Question

My car is 1996 honda accord lx. It's just weird. i goes up fairly quick and goes down fairly quick.

Answer 1

This is normal.
When your car is running and not moving, the coolant is circulated through the system, but NO AIR is moving through the radiator to cool it down.
When the car is moving, the air flowing through the radiator cools it down then it is circulated back to the engine (through the lower hose). When you rev the engine, you are increasing the rate that the coolant flows to the radiator, BUT it will not be cooled much due to the lack of airflow. You may notice a slight decrease in temperature, but this will spike since revving the engine generates heat faster than idling it.
If then temperature rises enough, then you should hear the cooling fan come on, this will lower the engine temperature (just like driving around would) but once the temperature has lowered enough, then the fan will shut off and the temp will rise again.
If your cooling fan is not working, or if you notice the temperature enter the red area, then either drive the car to cool it down or pull over and shut the engine off, as damage to the engine and cooling system may result.

Answer 2

The gauge would not be at fault. It is just a measuring device driven by the amount of current it receives. Check the thermostat, the coolant system for proper flow, clean the outside of the radiator since if it is dirty, and it likely is, then it could reduce cooling effect from the air. Is the coolant system full of water/anti-freeze as it should be, and check the temperature sending device to be sure it is working properly. Your system sounds like it has either insufficient coolant, the temperature sensor is defective, or the thermostat is not working properly. Your pump could also be defective, or is not being turned fast enough. Check the belt that drives the pump for proper tightness. You should not be able to push the belt down more than 1/2 inch in the center of the span between two drive pulleys. The thermostat is at the end of the hose coming from the radiator, where that hose connects to the block of the engine. The temperature sensor is either going to be screwed into a port on the block itself, or is screwed into the radiator.

Answer 3

Hey its really simple... when your car is idle, the water is not circulated in the radiator and the heat is stable and hence the guage shows the higher temperature,, when the engine is revved up, the radiator fans also speed up and circulate the water more which tends to bring the temperature of the water down, since it mixes with more air... thats all there is to it.. its perfectly a normal phenomeon...

Answer 4

Its either your fan not coming on or the tubes in the radiator is stopped up. Probably the fan(s) being when you drive around the air is forced through the radiator but could be the other...

Sit and let it idle and heat up and see if the fan kicks on. They should kick on somewhere around 212 - 225 degrees. Don't let it get too hot waiting, if they don't its probably the temp sensor, if the fan runs and car continues to heat, I'd be looking into the radiator

Answer 5

Start car ,watch to see if the Radatior Fan comes on at mid range,if temp keeps climbing.Fan relay.or fan motor,This check
done while car is not moving ,I prefer to be close to wall of my garage,it will reach 190 degree faster.additional check for fan motor,eng not running hands clear,disconect fan motor ,run wire from Batt,pos terminal to motor ,should work.

When you are driving you are getting air flow thru Radiator

Answer 6

the water pump circulates more water at higher RPM, when the water in the motor sits for second, its temprature increases and it shows on your gauge. This happens in all vehicles but they usually have a delay so it doesnt show so much change on the guage. No worries, but consider having the water pump replaced anyways.

Answer 7

when you say go up do you mean to red. if not red your car working great if pump leaking you will see drip s a round the bottom and this will take you to red . i just put a new rad in my car doing the same it up to you all new pump or new rad and one thing if your car wont cool when moving stay a way from motor way because than you will have to cool down when moving my one stays in the middle
when i move go near blue with a new rad

Answer 8

Engine always gets hotter when you stop or significantly slow down, since less coolant getting pumped through the block and less air being blown on a radiator.

Answer 9

Might be bad gauge! Or it could be normal my car also goes up really fast on sitting still; but I found if I turn on the A/C it goes down fast also.

Answer 10

This is normal operation. This is why there are cars that overheat in bumper to bumper traffic jams as air is not flowing thru the rad cooling the coolant.