How do I check a car thermostat with boiling water?

My car is overheating. I put in a new thermostat, test drove it - it overheated and the coolant backed up big time into the overflow tank. A guy said to pull the new thermostat, drop it in a pot of boiling water and %26quot;see if it opens.%26quot; He said sometimes you get a new one and it's bad. So I did that. The copper button moved out some, but how do I tell if it %26quot;opened?%26quot; Should I be able to see light through it at some points?How do I check a car thermostat with boiling water?First off, if you drop the thermostat into boiling water that is at least 190 degrees, you should see the center disc move away from the outer disc.



On a more realistic note, I doubt you have a bad thermostat. What was your reason for replacement in the first place?



If the car wasn't overheating originally, more than likely you have an air pocket in the cooling system. Many cars come with a bleeder somewhere in the cooling system that allows air to escape. If you do not bleed the air out, you have a cavity with no coolant. This expands at a different rate than the coolant and can cause some serious issues with the vehicle. Please respond with more information about why you replaced the thermostat and what kind of car you have.How do I check a car thermostat with boiling water?drop new thermostat in boiling water.you should see it open up.i used to leave mine out if i had alot of problems.it takes longer for you to get heat from your heater tho.it's not best to do.it will open if it's good.How do I check a car thermostat with boiling water?Yes.



If you have an old car, like mine, and it is not an electronic thermostat (It's in line from the radiator into the intake manifold) you really don't need it.



Next, look at the structural integrity of your radiator. If it's corroded and alot of fins are gone, it isn't doing it's job and needs to be replaced.



Also do a bit of a tune up. Check and change the oil and tranny fluid. If they're low, they can cause overheating. Make sure you also have a good ground strap going from the metal of the radiator, from the attachment points, to the body of the car.



I live by the beach. About every 6-8 years, I have to replace my radiator from salt corrosion.How do I check a car thermostat with boiling water?No, no-leave the thermostat out, and put everything back to gather. Run the car for an hour or so. If it heats back up, then that was not the problem. Look at the water pump or radiator could be plugged. If it runs cold, then either the thermostat was bad or in backwards,How do I check a car thermostat with boiling water?do not run without a thermostat , you need the restriction to allow the heat transfer to take place , that's how heads and blocks get warped. try a rad flush , look at the rad for blocked tubes etc.hopefully it's just crud that the flush will get rid of, good luck.How do I check a car thermostat with boiling water?the reason it overheated and backed u pcoolant is because the system was air locked,you will need to bleed the air out of the system,some engines have a bleeder in the system up high or you can loosen a heater hose to let the air out,being careful not to burn yourselfHow do I check a car thermostat with boiling water?Lots of incorrect info out there. To answer your question, you need a thermometer or a way to measure water temp. Put the thermostat in a water filled pan and apply some heat. Once the water temp reaches 180 degrees, or whatever temperature is stamped into the thermostat, the center of the thermostat should move or open up. Not all thermostats open at 180, some open higher. You can run without a thermostat, but it I don't recommend it. I have known people who do it all the time without any trouble at all, but I won't. It's also very easy to put the thermostat in backward. That's not good either. Make sure it's in correctly and bleed the air out of the system.How do I check a car thermostat with boiling water?its also possible you have other troubles,,,check your radiator hose's,,if they feel soft and you can squeeze them together( then they are bad) when the water gets hot,the vac *** will cause the hose's to collapse and make the car over heat,,,,the radiator might be plugged up and need flushed out,,check the grill area of the radiator,,might also need to cleaned out(gets filled up with bugs over time),,make sure you have the correct amount of water-anti freeze,,,,and its also possible that the temperature sending unit could be bad giving a false reading of a high temperature,,,,as for your question on how to test a thermostat to find out if its good or not,,boil some water in a pan,drop the thermostat in and watch to see if it opens(would be a good idea to have a thermometer to see the temp of the water being boiled) good luckHow do I check a car thermostat with boiling water?Did somebody replace the bottom radiator hose by any chance? People are always leaving the springs out of those things and they collapse from the water pump suction.

It's ok to leave thermostat out as a test, but Mazz is an idiot. Thermostats aren't there to cool the engine. They're there to keep the engine hot enough. It would run like crap and emissions would skyrocket if it was too cold.