Twenty Reasons Why Your Engine is Overheating In this Truck Radiator guide we are going to go over 20 reasons why your engine may be overheating. There are many causes of engine overheating and while we won’t go over all of them, we will point out some of the main causes of engine overheating and point you in the right direction.
Radiator hoses are a vital part of the cooling system that carry hot coolant from the engine through the radiator and circulate it back — cooler — to the engine again. There are two hoses, the upper and lower, and they’re thick and sturdy enough to handle both high pressures and immense heat. It should therefore strike you as odd if you notice one or both have collapsed. Don’t panic, however, as radiator hose collapse is usually a straightforward fix.
Nothing Happens in a Vacuum…Except When it Does
First of all, it’s important to note that some engines are designed to push coolant through the top hose, the radiator and then out the bottom hose. In others, however, the pump is placed to circulate coolant in the opposite direction, through the bottom of the radiator. This means one side (where the pump is) is the higher pressure side. Knowing how your cooling system is laid out will help you diagnose issues later on. Depending on the problem, one or both hoses can become flattened, and there can be different contributing factors. First and foremost, though, a collapsed radiator hose is the result of a vacuum condition. Usually, this is caused by a clog or constriction somewhere in the system.
Signs of Trouble
![Taking radiator cap off when hot meme Taking radiator cap off when hot meme](/uploads/1/2/6/2/126265771/180694048.jpg)
Maybe it only happens at high speeds or during engine revving, or maybe you notice it under the hood when the engine is cool. Perhaps an overheating engine prompted you to root around in the first place. A collapsed radiator hose doesn’t always make itself known, so it’s best to be vigilant and look under the hood every now and then. Engine overheating is not necessarily a cause or effect of a collapsed hose.
Causes and Fixes
The most common cause for radiator hose collapse is a vacuum issue caused by a faulty radiator cap. Caps are rated around 14–16 psi. Under normal circumstances, caps should release the negative pressure caused when an engine cools down and the liquid coolant contracts. They do lose their rating after years of use or sometimes they simply become too dirty to work. In these cases, all it takes to fix the issue is a new cap. Just make sure you replace the old one with new cap of the same pressure rating. Another common problem is clogging of the smaller radiator runoff hose, which leads to the coolant tank. As the engine cools, if fluid cannot return to the tank, this will also cause a vacuum. Additionally, it is possible that your radiator is clogged or dirty, but if that’s the case, you’re likely to have some overheating. Remember: Never open or remove a radiator cap from a hot engine.
Hose Condition
Just because the hose is collapsed doesn’t mean it’s bad, but you should always double check. If the hose is easy to pinch together, feels loose or sticky or looks cracked, it’s time for a replacement. Many times hoses come with an internal spring that maintains their shape, even in a vacuum situation, so don’t be surprised if a broken or missing spring allowed the collapse in the first place. Changing a hose isn’t too hard, but it can be messy. Be prepared to drain all your coolant in the process.
![Open Radiator Cap While Running Open Radiator Cap While Running](http://assets.superstreetonline.com/f/28727681.jpg?)
Always keep safety in mind when dealing with the cooling system. Beware the dangers of hot coolant under pressure and take-no-prisoners fans. If you’re unfamiliar with cooling systems, it’s best to consult your local NAPA AutoCare before moving forward.
Check out all the belts and hoses available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on radiator hose collapse, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
I have a 2003 Nissan Pathfinder with about 95,000 miles on it. Back in about September 09 the thing starts overheating. We have changed BOTH the thermostats and thought we would start there. Nope..we got a code the 'swirl control valve' was bad....that has been changed and the thing was running great! Then in February it started again. The only time that the check engine light comes on is after it overheats to tell you 'hey the car got hot'. After that one overheating episode in February it didn't do it again. Then a few weeks ago while running errands it started it again. Turn the heater on and it stops....we changed the water pump and it was great for 2 days then WHAM...here we go again. The radiator has been flushed twice. Pulled both of the thermostats out and ran it like that a while and it still over heats. There is no visible evidence that the head is cracked. The gauge goes all the way to the top....when you stop and idle and rev the engine the gauge drops. When you turn the car off and then get in it later the gauge is fine and take a while to raise again. But when it says that it is overheated...you get out and lift the hood there is no gurgling over ...there is nothing in the overflow and there is no 'hot' smell
HELP....we are out of ideas and have a big trip planned soon.
Thanks for help in advance,
~Wynde
HELP....we are out of ideas and have a big trip planned soon.
Thanks for help in advance,
~Wynde