Off and cooled down. Putting cold coolant into a hot block can crack it. And it can damage the radiator, as well as spitting the coolant back at you.
You should add coolant with the engine off and cool, top off the radiator and fill the coolant reservoir to the cool or cold level. When the system is hot or running it will be pressurized and will be dangerous to open. You can however add coolant to the overflow reservoir at any time.
You add the coolant to the reservoir tank located on the passenger side of the engine bay. Run the engine a little. Top off as necessary. If the car's a North American model, the resevior tank is located on the drivers side of the engine bay.
You can check the coolant reservoir when the engine is cold, if the coolant level is below the add line top it off with the proper coolant, not just water. It is not a good idea to add just plain water. You should use at least a 50/50 mix of water and antifreeze.
It is normal to boil when you turn the car off. When the coolant stops flowing, the coolant in the hot engine boils and pushes steam out of the engine. The recovery tank collects the excess and allows it to go back in when the engine cools.
no you check your oil with car off easier when car is cooled off
After coolant is added run vehicle to normal operating temperature and re-check coolant level
Make sure the car engine is cooled off, preferably early in the day before the car has been started. The coolant tank is on the passenger side under the hood. Fill the tank to the line that says "full..cool" and you're done.
You may add coolant mixture to the bottle inside the fender at any time. It is safer to add to the radiator when the engine has completely cooled 3-4 hours.
The engine will overheat and can cause severe engine damage. The engine will be completely ruined if it is not immediately shut off.
Add the coolant into the coolant reservoir. Be sure the engine is cool when you remove the cap off the reservoir.
why does the coolant only leak when engine is off on my 1999 grand am?
1.) WITH THE ENGINE OFF! and the ENGINE COLD! -take the radiator cap off and see if you can see water (or coolant) inside. If not, add enough water or coolant until it you can see it. Put the cap back on securely.2.) WITH THE ENGINE OFF! and the ENGINE COLD!-Check to see if the belt that runs over the pulley that turns the fan behind the radiator is tight. It should push in about an inch by just pushing it with your finger. If not, tighten it or have a mechanic do it for you.3.) WITH THE ENGINE OFF!-Check to make sure you have enough engine oil in the engine.