Clogs in the radiator or somewhere else in the cooling system can be a bit harder to nail down. The best way to find problems like this is with an infrared thermometer.
With this tool, you can check localized temperatures within the cooling system. One example is using this tool to check the temperature of a radiator across its surface. If you’re checking the temperature and you come across a sudden change in temperature, this could indicate a blockage in the radiator. On a normal radiator, you should see a gradual change from hot temperatures at the top to cooler temperatures at the bottom of the radiator. I don’t see radiator blockages often, but when I do, this is a good way to find them. When I see this problem, it’s often associated with improper use of stop leak products. I’ve also come across it on vehicles that have been sitting for long periods of time. Say the vehicle has a salvage yard engine; that engine might have been sitting at the salvage yard for some time and, as a result, accumulated a lot of rust buildup inside the block. Once the engine is running again this rust and scale breaks up and clogs the small passages inside the cooling system.
I’ve also seen this same issue arise from not running coolant in the cooling system. I’ve had viewers from tropical climates tell me that they just run straight water in their cooling systems. This is a very bad idea because coolant also lubricates the system and prevents corrosion. It also helps raise the boiling point of the mixture and assists in cooling system efficiency. Running straight water instead of coolant can cause the entire system to corrode from the inside and possibly cause the above-mentioned blockages. So don’t run straight water in your cooling system, no matter what your climate is.
Video Title: Radiator Restrictions – What to Do When Your Engine Overheats – EricTheCarGuy Video Description: In this topic you will learn about Radiator Restrictions and What to Do When Your Engine Overheats. Thumbnail: http://www.ericthecarguy.com/images/faq_buttons/Large_FAQ_Images/engine-overheat-Icon-large.jpg