Good Uncle's Guide on How to Handle your Engine Overheating

First thing is first.  Heat is the easiest way to damage more than just your engine.  It can damage your heater, electrical system, cooling system, and in very rare occasion can even cause a fire!

With this in mind, overheating vehicles need to be treated with urgent attention if you have any interest in protecting your asset.  The number one rule of handling these situations is DON’T RUN THE CAR.  The consequences can easily go into the $1000’s if not handled correctly.

With that being said, this does not mean you are stuck.  The most common reason a vehicle overheats is because of coolant loss to the extent that the water pump can no longer circulate coolant through the system.  Within 30 seconds of the fluid sitting still, the engine begins to run hot.  If you have a temperature guage that keeps going up and down, that usually means you are getting occasional circulation from pressure build up (from the extra heat).  This can blow a hose or seal, causing more problems then you originally had.  

Now, lets get to what to do after you stop the engine.  Before you open the hood, wait a minimum of 5 minutes.  We have a volatile situation with this extra hot engine that is creating a lot of pressure.  Often times, you will hear a bubbling from the coolant hitting a boiling point.  Anti-freeze / coolant is designed to have boiling temps well beyond water, so this is certainly another indicator it is truly overheating.  If after 5 minutes you still hear boiling sounds, wait until the sound goes away, and maybe even another minute just for safety’s sake.  Now, you can open the hood.

This next part is VERY important.  You do not want to open any radiator caps or reservoir caps while they are hot!  The reason for opening the hood is to help the cool down process!  While the hood is open you can evaluate any obvious leaks, but to be efficient with your time, use these moments and figure out how to get some kind of water / antifreeze if you don’t already have any. If you have to use water, the cleaner the better.  Avoid tap water as much as possible, while ideally we want distilled.  If you can keep it to distilled or purified water, you avoid needing a coolant flush down the line.  We will want at least a gallon - doesn’t hurt to have more though.  

Once you have some form of liquid to add, you want to also insure it’s been at least 30 minutes after you have shut the engine off.  At this point, we can add fluid.  If there is a radiator cap, you want to fill through there first.  While opening the cap, go very slow.  If there is still any steam or  pressure, twist it back on and wait another 10 minutes.  If not, continue to take the cap off slowly.  Keep your face as far away as possible while doing this.  After you have filled the system, run the engine for about 30 seconds, and turn it off.  See if the fluid levels have gone down (most likely they have).  Refill as necessary.  Next time we start the engine, look for any obvious leaks. Let the vehicle warm up for a few minutes before putting any stress on the engine.  Is there a major leak?  Occasionally, the fluid will dump right back out, and you are not in a position to drive.  A small drip is something that is acceptable to get us somewhere better than the side of the highway or road.