Many drivers are in aging, rebuilt or refurbished vehicles that run as close to new as they can with limited funding. Although it's possible to get a good used car that has a few major repairs, there's a lot that could go wrong when dealing with hundreds of precision screws holding hundreds of moving pounds of metal together. One issue is overheating, which can change the shape of many metal components and lead to permanent damage. If you've noticed rattling sounds or white smoke puffing from your exhaust pipes, reduce your driving and have a few areas looked at. 

Where Is The Rattling Coming From?

Oil can be the source of many of the overheating rattling problems. In vehicles, oil is used to lubricate moving parts to reduce friction and keep parts intact for as long as possible. This oil used at a much higher rate than oiling a door hinge or removing rust--some components are nearly submerged in precision components or at least well drenched while moving.

One set of parts would be the cam, camshaft and the cam follower. The cam is an often egg-shaped series of rotating discs on a bar within a shaft, used to rotate and push down against levers called cam followers, which provides movement for intake and exhaust valves (moving air in and out) of the vehicle's cylinders. 

When there's a lack of oil in the camshaft or any similar component using oil, the components can move against their containers and cause rattling noise. These metal parts are banging against their walls at high speeds with a lot of applied pressure, which can bend or warp the metal and make the car inoperable.

If the parts are damaged, they won't be able to make contact with certain other parts at the right time (or at all), which will throw off the timing of the engine. For engines, timing is everything, and the engine won't start if the cycle can't continue with thousands of revolutions per minute (RPM).

Symptoms To Watch Out For

For these symptoms, it's important to safely stop driving as soon as possible. Don't brake in the middle of traffic or veer off of the road at high speeds; although the engine damage can be severe, it's not worth getting into a more expensive (or potentially lethal) accident.

First and foremost, pay attention to your vehicle's lights and indicators. The overheating, low oil and low-pressure lights are key here, as they can all affect each other. Overheating causes metal to expand, which can make high-speed parts touch each other with a lot of force and potentially damage a lot of components.

Rattling in the engine from the previous examples is one key symptom, but it's often accompanied by white smoke. The white smoke means that water from the engine is getting into the valves of your vehicle. Water getting into the valves means that overheating is already taking place or that you drove over a large amount of water.

For overheating, it means that the heads attached to your car's cylinders are expanding and allowing fluids in. A similar issue happens when blue smoke leaves your exhaust, which means that oil is leaking into the cylinder valves. 

There's always the chance that your car's indicators may not be working because of electrical problems, so keep your eyes and ears open if you've seen any of these problems for even a short amount of time. One common mistake is to dismiss the issue as "fixing itself," which is actually an early warning that can be fixed at a much lower price than replacing an engine. Contact an auto repair shop (such as Blue Valley Garage) as soon as possible if your car is smoking or rattling at all.