This is the famous question we get so often, especially in the summertime. Inevitably, someone will come in with no leaks, and nothing "bad," just saying that their vehicle is getting hot. I have found that a lot of times people will blame the radiator, which is certainly the case sometimes, but there are many other things which could cause overheating. Here are the 5 most common things which can cause your vehicle to overheat.

1. Thermostat
   A thermostat can be blamed for both overheating and under-heating. When a thermostat goes bad, it will begin sticking and not opening or closing when certain temperatures are reached. When the thermostat is stuck in the closed position, it restricts the flow of coolant, causing the motor to heat up. If it is stuck in the open position, it will cause continuous flow through the system, never letting the motor get up to operating temperature. 

2. Clogged Radiator
  The radiator has some of the smallest places in the entire system. When trash and dirt make their way into the radiator, many times it will get stuck on the ends of the tubes, or even lodged in the tubes themselves. This restricts the flow of coolant through the radiator and lowers the amount a coolant that goes through the motor, causing it to overheat. Many people think a flush will unclog a radiator but many times is not the case. Usually, to unclog a radiator it will have to be removed and taken apart to be rodded, which is pushing a solid rob through the tubes to push the clogs out.

3. Low coolant/Leaky System
​   This is probably the most common reason, but usually easily recognizable. If a system gets low enough on coolant, then there isn't enough to go through the motor and cool it down enough. Usually the case is that there is a leak, small or big, somewhere in the system. The most common components to leak are the radiator and water pump, so it's best those are checked first. Nursing a cooling system and adding water or antifreeze every day to keep it up is never a good idea. By continuously letting it run low, you can put a lot of wear and tear on different parts of the cooling system, especially with all the plastic parts they put in them now. So get it fixed to avoid bigger problems!

4. Bad Head Gasket
   Speaking of bigger problems, this one is probably a worst-case scenario. If a vehicle has overheated too many times, it can blow the head gasket. This internal leak will actually push exhaust fumes straight into the cooling jackets on the motor, making them extremely hot. This type of problem is usually caused by another problem that was not fixed in a timely manner, and is one of the most costly on this list.

5. Bad Water Pump
   Although rare, a bad water pump can cause a vehicle to overheat. The belt drives the pump which turns inside and directs the coolant forward.  In the rare case that the shaft connecting the pulley to the impeller breaks, then the drive belt will no longer be pushing the water, causing very slow and weak flow.

If you have ever shopped around for an aftermarket radiator, you may already know the abundance of brands that are out there. If given a choice, you may not have known exactly what to go with, or whether it even mattered. If you were lucky, the retailer/mechanic/seller gave you an honest opinion about which brand was best, if there was a "best." Deciding what brands are of high quality and what brands are of low quality really depends on a number of factors.

I think the most important quality is the fit. I mean, what good is a radiator if it doesn't fit right? Radiators can have several factors that could cause it too fit slightly different such as the dimensions, location of the mounts, hose connections, core thickness, and cooler fittings just to name a few. These are always a good thing to check before you buy a radiator.

Another quality difference is the plastic quality and the aluminum quality that is used. The quality of the materials can cause a radiator to last for years to come, or lead to its demise after only a year. The way most radiators go out is the fact that the plastic cracks, or the header leaks in the corner. Using higher quality materials can drastically change the life of the radiator. however, you still have to remember that wear and tear always happens slower by taking care of the vehicle.

The final major factor of quality in a radiator is the core thickness. If the original radiator has a 1.25" core , you don't want to replace it with one that only has a 1" core. Several radiator companies will reduce the size of the core to cut costs for a cheaper radiator. This way seem fine at first, but it can cause overheating in the future, and even help the core fail. 

With that said, you know what to look for in a good radiator. Just because a radiator is made in China (most of them are) does not necessarily mean it is of low quality. Every brand has certain radiators that don't work as well, while others that they sell are some of the best out there. As far as actual good brands, I would say some of the more consistent brands with high rates of good parts are GPD, Champion, NRF, Koyo, and Tong Yang. The only one out of these brands not made in China is NRF, which are manufactured in India or Taiwan with its corporate office in the Netherlands. GPD and Champion are both American owned and run, while Koyo and Tong Yang are both Chinese owned and run. Some brands that we have seen a decline in quality are CSF and DixinUSA. We have ran into several cases lately where these brands didn't include the necessary hardware, or the cores fail early on. Radiator brands which we have seen the lowest quality, or highest amount of problems are Silla and Reach. Silla radiators we have found are of low quality materials and have a high fail rate. We have had several cases in times past when Reach radiators had a failed transmission cooler, causing coolant and transmission fluid to mix.

What it all boils down to is that every brand has its ups and downs. The best way to get the best radiator is to go by the guidelines expressed above and to get the best product, or trust the radiator expert near you!

   Some scoff at the thought of aluminum radiators, as they are used to the old style brass & copper radiators that were run in cars and trucks for decades. In the last 20 years, aluminum radiators have been taking over and all automotive radiators are now plastic & aluminum. But did you know that aluminum radiators actually perform better than copper radiators? Yes, it's true, Aluminum radiators can get away with a whole row of tubes less than copper radiators can; e.g. a 3 row Brass/Copper is equal in terms of cooling to a 2 row Aluminum radiator. 

     Vehicle maintenance - the most important thing to do to keep your vehicle running for a long time. Oil changes, transmission service, brake pads, chassis lube, tires, etc; all things that you probably think about when maintaining their vehicle. But do ever think about the cooling system? I'm not talking about pulling off the cap and checking the coolant level, that's elementary stuff. Is your coolant clean? Is your coolant flowing? Have you checked for stains on the radiator or water pump? These are questions to ask yourself about your car, and if the answer is "no" to any of these, you should probably do some checking!

   Most vehicles over-time without routine flushes will build up dirt and grime inside the cooling system resulting in brown, mud filled anti-freeze. Once you get a dirty system, it can start to cause loads of problems from clogging to breaking down gaskets and seals creating leaks. Systems with orange anti-freeze such as GM's Dex-Cool are especially vulnerable. We actually recommend having the orange flushed out and replaced with a universal antifreeze. 

The dirty system needs to be avoided altogether. This can done by routine annual flushes to your cooling system. Taking it to a mechanic to flush usually doesn't cost a whole lot and is well worth it as it gets rid of all dirt and grime and your old coolant is replaced with brand new coolant. Also if you have any clogging or restriction, this can free up the passageways.