Q: Temperature needles moves to "hot" when idle but goes back to "cold" when moving.

asked by on November 28, 2016

Our temperature needle always goes to the red line when we are idle, only. If we are moving, it stays closer to the "c". If we stay idle and the needle goes to red the low coolant light comes on and keeps dinging until we move again. As soon as we move, the needle moves. There is never any smoke coming from the hood nor does it ever smell as if it's running hot. Also, our heat starts blowing cool air when idle. Today, the vehicle started shaking. Could all of these problem be related?

My car has 140000 miles.
My car has an automatic transmission.

Car is running hotter than normal Inspection $94.99 - $114.99 Get a Quote

The engine temperature fluctuating as it is can be caused by a number of components or problems. If the cooling system is restricted, coolant flow may be reduced at low engine speeds (idle) and be better when moving. If the cooling system has not been serviced for a long period, coolant passages in the radiator, heater, and engine may be restricted enough to limit coolant flow. Low coolant level can cause similar symptoms. Also, electrical issues can cause the vehicle to run hot at low speeds. If the radiator cooling fan is not turning on, the temperature will rise until you begin moving again, getting air flow through the radiator.

Have a certified technician diagnose the running hot issues as soon as possible. Running hot can cause performance issues as well as severe damage to the engine.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Vehicle will not start.
Cranking and turning over are both referring to the starter cranking or turning over the engine. If the key is turned inside the ignition and no sound is heard while attempting to start, the starter may be faulty. If a...
Truck does not start
Hi. If the engine cranks normally but doesn't start, most likely the engine is not getting fuel or spark. Just because you have fuel pressure from the pump doesn't mean that fuel is getting to the engine. In modern vehicle,...
Check Engine light; upstream O2 sensor
Hi there. If you have a code for the upstream O2 sensor then that is the most likely problem. Knowing the code would help me to be able to tell for sure what is going on. If you replaced the...
EWS code
The EWS (Electronic Immobilizer) light on your BMW is an alarm that will cause your car to not start. Something you can attempt is using a different key to start your BMW. If after trying a different key, the car...
Acceleration problems, car shaking and check engine light on
Hi there. There are a few different things that can cause this. It can be the fact that the speedometer is not working due to a bad transmission speed sensor. This can cause the computer to not know when to...
should I replace this alternator or get another car?? I am a senior citizen without a lot of money
Your problems do not sound related to the alternator specifically. I would not replace it unless it has been checked and confirmed to be a problem. With the number of issues you are listing, your money may be better spent...
My car is starting to over heat and lose speed and I lost heat as well. There is a white smoke coming through my vents
This sounds like the heater core may be leaking. Typical symptoms of a leaking heater core: smoke/steam through the vents, sweet smell, fogging of windows. The heater core is typically located behind the dash. It is part of the heating/cooling...
Changed DPF and still getting warning lights. Can't work as taxi driver, please help (Lexus 220D)
Hello. If the trouble codes are indicating that the dpfe is blocked, then there may be an obstruction in the system, or perhaps an electrical issue. The dpfe sensor functions using vacuum and exhaust gases. If there is an obstruction...
My 2014 ford focus whenni hit the lock button on my remote the beep does not sound and the horn does not work either.
Hello, thank you for writing in. The vehicle has a fuse that is specifically for the horn, and you are going to want to check that first. If the fuse is blown, it is a simple fix in which you...

Related articles

A Buyer’s Guide to the 2012 Buick LaCrosse
Over Over the past several years, Buick has returned to form when it comes to luxury sedans, and the 2012 Buick LaCrosse is a standout even when compared to some of the other big names in luxury. Key Features The...
2005 Kia Sorento vs. 2005 Chevrolet Blazer: Which One Should I Buy?
SUVs are great for playing out in the mud, taking kids and friends around to different places, as well as just running errands around town. While they are not known to be terrific for gas mileage, that problem is negated...
The Best Used Cars to Buy If You Get Motion Sickness
For For people that suffer from motion sickness, even on the shortest car trip, riding in a vehicle can prove to be unbearable. What’s great is that there are a number of cars on the market that can help to...