Pouring Water Into Radiator

Pouring water into a radiator?

You would put a STEAM burn on your hand that you would NEVER forget. You would also blow the head gasket by the suddden release of the water pressure. If you have to remove the radiator cap, be sure the engine is cold. because if you don't you bought the engine, and failed your Mr. Goodwrench course.

Why it's wrong to add water to the car radiator while the engine is warm and not running ?

It is not wrong to add water to a warm engine. It is only that the pressure in the radiator must be reduced first and safely. The layman cannot do this safely and that is why manufacturers take the safe way out and tell you to add when cold.

Most times, if the plastic reservoir has water in it, the only thing needed is to fill up the reservoir to its high mark level. That is sufficient and should be done cold. When the thermostat opens the water will be sucked in, if there is a need. When the water temperature rises, the excess water on expansion is channeled back into reservoir. The water is sucked back into the system when it is cool. In this manner, the water need not be refilled regularly. A check once a week is sufficient for a secure and non leaking system and water is only needed to compensate for evaporation from the reservoir.

However, if you have allowed the water to dry out in the reservoir, you will need to open the radiator cap.Do this when the engine is touch warm or cold only. Fill the water to the top. Do not replace the cap yet. Keep it on a safe place away from the car engine. Start the car and let it idle until the water is running through the system. You can see the water swirling across the neck of the radiator when the engine is warm. This is when the thermostat is open. Fill up the radiator until the neck of the radiator if needed. Do it carefully as the engine is running and is a potential danger to you. After you have done so, stop the engine, replace the radiator cap firmly and fill up the reservoir to the high level mark. Now, you are well and ready.

The reason for the engine running technique is to allow the thermostat to open and any trapped air to be expelled. Air is seldom trapped but when the level of the water is low enough you can have trapped air. Too much bubbles of air is not good in a radiator system.

One last thing, check the water level in the reservoir everyday for a week. Any serious loss of water could mean a leak somewhere in the system.

By the way a cold running engine is not as efficient as a fairly warm engine.

Isn't cold water bad for car radiator ?

Cold can be bad for a radiator, (not cold water), if temperatures go below freezing.
You might go snow skiing, overnight the water ices then because water expands when it freezes the radiator & the block are damaged. Not a good holiday. Where temperatures are low, use 'Glycol', to lower the freezing point of the water to -40C. With it added you'll have no problems.
As a counter point, never take off a radiator cap to top up a radiator thats over heating. The radiator will vent steam and scald you. If you really must do it, use heavy leather gloves or a very thick rag pad.

Is it safe to pour water directly onto your engine?

Damage. The engine is relatively hot compared to what it should be. That is actually pretty hot compared to air and water's temperature. By pouring relatively cold water on it, it cools extremely fast. Since the part that the water touches is cooled first, there is unequal movement and stress on the metal.

The result can be cracks. Sometimes it is so bad that you can actually see the crack. Other times, it is more subtle, but still is damage. It won't break every time, but why take a chance. Even putting cold water into the radiator can cause problems.

Additional: Ramon's answer was a bit harsh, but rather amusing and on target. I gave him thumbs up. You really need to do some research about cars if you don't know how to safely do things.

I put cold water in my overheated radiator while the car was off.?

You could have cracked or warped some of your engine components.
My dad put mountain stream water (cold) into and overworked full-size van on a mountain trip as a child. Upon returning home the warped heads needed replacing.
I had my suburban serviced in California before the long drive back home in Oklahoma. Somewhere between LA and Kingston my engine got hot and I pulled over. Pep Boy "mechanic" didn't put my radiator cap back on after servicing. It was literally laying on the radiator upside down beside the hole! I luckily had a cooler full of Aqua-Fina water bottles and promptly poured them into the near empty radiator. Remembering dads plight, I sat for 3 hours in the middle of nowhere to let the cold water warm up before attempting the drive home. That was 50,000 miles ago with no related issues.
You should know soon if your engine was harmed. Good Luck.

My brother accidentally poured beer into my radiator. Should i worry?

not truly because of the fact the alcohol differences the residences of whilst it boils... Now in case you get a crappy beer like a bad homebrew that the guy do not understand the thank you to purify all of it that properly, you may probable pour it in and end the leak this is costing you. i might propose a heat beer like from Germany.. the people in straight forward terms like it chilly while you're gonna positioned it in... additionally why do not you recycle? Beer into you... beer intestine purifies and as a replace of hitting the urinal, hit the radiator tank as a replace... you and a few friends ought to help get that double funding going that way (taking section in the beer and releaving your self in a great way) If not, bark root in radiator end leak will shelter the leak and the radiator tank for a head would desire to shelter something