Skip the auto shop - Our mechanics make house calls

Q: Coolant Temperature Gauge

asked by on

I have a 2007 Audi Q7 Premium 4.2 Engine. My temperature gauge is extremely slow to reach operating temp even after driving. I changed the coolant temperature sensor with a auto parts store sensor it helped briefly. Could this be because I need to use dealer oem part in Audi or a bad Tstat? Also the fan does not kick on to cool the engine after driving

My car has 106592 miles.
My car has an automatic transmission.

A: Hello. This potentially sounds like a combi...

Hello. This potentially sounds like a combination of a faulty thermostat that may be stuck open and possibly a faulty coolant temperature switch that is causing the cooling fans to not come on. For a more precise diagnosis, I recommend having a local expert, like one from YourMechanic, to inspect the cooling system in order to have this correctly addressed.

Was this answer helpful?

A: This problem is likely caused by a failing ...

This problem is likely caused by a failing thermostat. The thermostat is designed to restrict coolant flow to the radiator until the engine reaches designed working temperature (something close to 210 degrees Fahrenheit). Getting to working temperature faster is important for fuel efficiency, lower emissions, better flow of oil within the engine, faster "time to heat" for the heater, etc. If the thermostat is not allowing the engine to reach, and stay, at designed operating temperature, the auxiliary fan will not turn as well; since it's activated by the engine reaching a certain temperature. I would recommend a Thermostat Replacement service which would be performed by a certified technician from YourMechanic. This will allow the confirmation of a diagnosis, and to give you a better idea for repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
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・Save up to 30%

Get a quote

What others are asking

Q: My gas gauge is doing a funny little dance.

The fuel pumps are all inclusive on what they call a fuel module or assembly. These modules include a float (quite like the float on your toilet) that tells the computer and your dashboard where the fuel level is at....

Q: My car keeps running hot then it cools down

Hi, thanks for writing in. There are two possibilities here: either the physical temperature of the engine is indeed fluctuating significantly, or the sensor and/or circuit that feeds the temperature gauge is malfunctioning. The sensor (and circuit) can be tested...

Q: Temperature gauge -- engine running cooler than normal. Below 90 only while driving.

Hi, thanks for writing in. If the engine is running cooler than normal, this could mean the thermostat is stuck in the open position. This will cause the engine to run cold and not warm up properly. This can cause...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.