Has the temperature warning light on your Audi's dashboard come on? Are you nervous about bringing it to the mechanic, because you expect that it'll be an expensive repair? Sometimes a vehicle's temperature warning light comes on because of severe, pricey problems such as a bad water pump or damaged radiator; but sometimes the problem is small and requires nothing more than a quick, cheap repair. Read on to learn about 3 easy-to-fix problems that might be the cause of your temperature warning light.

Low Oil Level

It's likely that one of the first things you did when your temperature warning light came on was check your car's coolant level, but did you check its oil level, too? 

The parts of your car rub and grind together when in operation. This friction creates an intense heat that would harm your engine if not carried away from it. Thankfully, oil takes care of this problem by both lubricating your vehicle parts to limit friction, and transferring much of the heat that is produced away from your engine.

If you don't have enough oil in your car to do this job, though, your vehicle is bound to overheat. Since Audis are known to consume oil quite rapidly, an inadequate oil level very well may be what's causing your problem. Luckily, engine oil is under $5 a quart at nearly any gas station, auto shop, or box store in the country, making this one of the cheapest and easiest possible fixes for a temperature warning light.

Bad Radiator Cap

The radiator cap in your car is more than just a cap -- it's a pressure valve, too. As the coolant fluid in your car gets hot, it expands and builds pressure. Your radiator cap has a little valve on it that opens when this pressure gets too high, allowing some of the coolant to flow out of the radiator and into an overflow tank. From there, the coolant is cooled off and then circulated back into the cooling system. That is, as long as your radiator cap is functioning properly.

If your radiator cap is stuck closed, or if the gasket is worn allowing pressure to escape too soon, it can cause your car's cooling system to malfunction and throw a temperature warning light.

Before you start researching the price of replacing your entire radiator, check your vehicle's owner's manual to determine the correct pressure setting of your car's radiator cap, and then purchase a new cap with that setting. Make sure your car is turned off and completely cool, and then unscrew the old cap and put the new one on. This repair costs under $10 and less than a minute of your time.

Malfunctioning CTS sensor

Your car's coolant temperature sensor (CTS) constantly monitors the internal temperature of the engine, and then relays that information to your car's computer. The computer then makes adjustments to your fuel injection system, as well as your ignition and valve timing so that your vehicle is always running at optimal performance.

When your CTS isn't working properly, however, your computer won't be able to detect temperature changes and a whole slew of problems might arise. 

If your car's temperature warning light is accompanied by starting problems, or by increased fuel consumption and high emissions (characterized by black smoke coming from your tail pipe), then a malfunctioning CTS is likely your problem. 

If you have a mechanic replace your CTS, you're looking at a fee of roughly $118 - $165. However, if you can locate the sensor and swap it out yourself, you'll spend only the price of the part, which generally runs between $31 and $54.

Just because your Audi's temperature warning light has come on doesn't mean that you're destined for a huge repair bill. Begin your troubleshooting process with the above 3 problems and you might find that your vehicle is far easier and cheaper to fix than you think. If you can't find the problem, however, take your car into an Audi service repair shop.