Chapter 8

Cooling System

Let's start off by discussing thermostats. If you car is overheating or if it takes too long to warm up then you may have a stuck thermostat. If your thermostat is stuck in the closed position, the coolant (antifreeze) will not be able to circulate properly most likely causing the engine to overheat. On the other hand, if your thermostat is stuck in the open position your engine will run cooler than usual. This may not seem like such a big deal, but it can be when you consider that when the engineers designed your engine they took into account the correct operating temperature. If the engine runs too cool the metal components will not expand like designed and, as such, the engine parts may all be too loose. In either instance, a stuck or faulty thermostat can, and probably will, cause your engine to wear more quickly. There are many specialty cooling system shops (sometimes simply referred to as radiator shops) that can replace your thermostat in under an hour. Local garages and dealers can also perform this task for you.

Your radiator is a key component of your vehicle's cooling system. Coolant (antifreeze) circulates through your engine block where it picks up the engines heat. The coolant then circulates to the radiator where heat from the engine dissipates before returning back to the engine block to start the process over again. Some vehicles (particularly those equipped for towing) have a second radiator like device for cooling the transmission. Vehicles without separate transmission coolers also rely on the radiator for transmission cooling purposes as well.

Over time you vehicle's radiator may start to leak. If you notice green or pink fluid under your vehicle then you may have a coolant leak. There are three possibilities when it comes to solving radiator problems.

Sometimes if you are lucky you can get away with simply repairing a leaking radiator. In some instances a radiator (particularly the older brass or copper radiators) can be re-soldered, but we should note that this may be a short term solution. On newer cars it is more common to see aluminum radiators, which are much more durable, but are generally much more difficult to repair.

A radiator consists of basically two parts. These are the core and the tanks. Sometimes a radiator can be recored which means removing your existing tanks from your old radiator and soldering them to a new core.

Even though it is the most expensive, it is often the safest bet to simply replace the radiator with a new one. There are many specialty cooling system shops (sometimes simply referred to as radiator shops) that can replace recore, rebuild, or replace your radiator for you. Local garages and dealers can certainly replace your radiator for you, but we suggest the specialty shops if you opt for the recore or replace options.