As your vehicle ages, the wear is accumulative all over the vehicle. There are practically endless investments that you can make to keep it looking and running like new forever. Yet, when it comes down to it, it is only practical to address major wear issues.
Most vehicles will start to develop a little bit of play in the steering wheel as they age, for example. This dead spot will make the steering unresponsive until you move it a little bit more to the left or right. Rarely, do drivers decide to replace the steering rack just because the worm gear is showing some wear. Yet, they may replace other steering parts such as control arms, ball joints, tie rods, and stabilizers. Let's discuss what part replacements are the best bang for your buck on an aging auto, below.
Coolant Temperature Sensor
The coolant temperature sensor plays a critical role in fuel management. When the semiconductor material heats up, the resistance will decrease. This is the opposite of most conductor materials, which usually increase resistance when heated. By measuring the resistance of the coolant temperature sensor, your computer can approximate the temperature of the coolant circulating through the engine and adjust the fuel mapping accordingly.
When an engine is cold, the fuel management computer practically dumps fuel into the engine until it warms up. Some motors will have a special cold-start injector to add additional fuel. As the engine heats up and reaches operating temperature, it requires less fuel because the pistons are hot and sealing the pressures more efficiently, among other things.
The problem with coolant temperature sensors is that they can fail without any symptoms. Unless you monitor them, you won't know if they are sending the correct readings to the engine management computer. And if they are within a normal range of operation, they won't illuminate your Check Engine light or trigger any DTC (Diagnostic Trouble Code) faults. The sensor develops internal resistance from heat over time and will send the incorrect signals to the computer.
By swapping out your coolant temperature sensor every 5 years or so, you can improve the performance and fuel efficiency of your vehicle immediately. They are usually inexpensive and require very little labor to install. For $100, you may save that much in fuel in a few weeks by swapping out a bad sensor.
The fuel injectors in your vehicle are little electronic solenoid-controlled valves that open and close in micro-pulses to squirt the ideal level of fuel in the engine at any given time. The fuel injectors have very fine nozzles that atomize the fuel into a superfine mist. Over time, the injector nozzles will begin to wear. Injectors may also get gummed up or begin leaking. Replacing worn injectors can significantly increase your performance and fuel-efficiency. If your vehicle has over 100,000 miles, it may be time to replace them.
Another critical part in the fuel system is the fuel filter. Although almost every vehicle has at least one fuel filter, this maintenance item is often overlooked. Although they are inexpensive and easy to replace, drivers don't typically fix things until there is a problem. Most know to change their oil and filter regularly but may not be sure when the fuel filter is due. If your vehicle dies out suddenly or sputters, you should always check for a clogged fuel filter before you try any other repairs.
The timing belt is the most critical component on your vehicle. If this belt breaks, your entire engine can come crashing to its death in a matter of seconds. Yet, when people buy a used car, they may not know what all work was done to it. And if they aren't sure when the timing belt was changed, they may put off the repair.
Some timing belts are due at 75,000 miles while others can last 100,000 or more. If you buy a used auto and you're not absolutely sure when it was last changed, please have it checked to be certain. Larger engines typically have timing chains that require less maintenance. They may start to rattle after about 200,000 miles but are far more reliable.