Q: Audi S8 2009 v10 overheating when idle

asked by on

My 2009 Audi S8 v10 (with 120k km) recently started running hot.

-When driving constantly, the temp gauge shows a normal 90C (12 o'clock position). -However, in stop and go traffic, traffic jams, at traffic lights, etc. it occasionally goes above 90C. Not much, barely to the next line, not above 110C. This doesn't always happen in stop and go traffic/ traffic jams/ traffic lights. Only sometimes. It never did this before, though. -After a 40 minute drive, when I park the car and the engine is still running, in idle, the front of the car is much louder than it used to be.. that fans are running very loud, and the grill in the front is very very cool (probably because of the intense fan speed?) -When I turn the car off, sometimes the fans stay on for 10-20 seconds, but mostly they just shut off along with the engine. -No engine warning light ever came on.

-Can I still drive it if it stays under 110C? How can I test myself what the issue is? Fan? Thermostat? How?


My car has 120000 miles.
My car has an automatic transmission.

Once operating temperature reaches approximately 220 F, you’re really considered at the limit. It sounds like you are occasionally above that so do get this resolved as overheating is a principal cause of shortened engine service life and can cause acute damage, too. Thermostat failure is not unusual. Indeed, it is not a bad idea to just replace the thermostat outright based on mileage. You could try that first but test the thermostat after you remove it, so you have further info if you need to continue with an overheating diagnostic (i.e., if the thermostat tests as faulty, that may eliminate the need for additional diagnostics). Buy and install ONLY a genuine OEM thermostat from the new car dealer to reduce diagnostic headaches. By the way, overheating will itself damage the thermostat and if a car has overheated the thermostat is automatically replaced.

The most common causes of overheating include low coolant level (including that due to leaks), a faulty thermostat, a plugged radiator, a faulty radiator pressure cap, collapsed hoses, non functioning cooling fans, and a faulty water pump or drive belt. Certain engine faults, such as a leaking head gasket, poor engine running condition or exhaust blockages can also cause overheating. If you desire that this overheating problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request an engine overheating diagnostic and the responding certified mechanic will get this resolved for you promptly. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Audi S8 2009 v10 overheating when idle

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

Get a quote

What others are asking

Q: Interested in purchasing a vehicle

As for the car itself, the Audi R8 is a fantastic car. Very sporty and likely extremely fun to drive. I can see where the option to buy one at a likely discounted price due to the flood damage would...

Q: leaking oil after fixed

Hello. The first step would be taking it back to the dealer where your car was fixed once more and have them inspect it to see if there is a new leak somewhere. There are several components that could be...

Q: Code P2102

Hi There, This code relates to the throttle control valve motor/actuator that controls the opening and closing of the throttle through a series of signals that the ECM controls and sends to the throttle control motor via a relay. When...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...