engine overheated!!!!

[the manzo]

hello, today my engine overheated. so i said ok ill just top off the water and let it cool off. so i did. but from the store to my house the temp started to rise above oe recommended temp. so when i got home i checked the oil cap to see if i blew a gasket. i didnt, thank god. but now i dont know how it overheated. the thermostat is only a few months old. what could it be?


thanks

 

[IZwack]

Remove the thermostat and test it. You can also run the vehicle for a bit w/o a thermostat and see if it still overheats.

 

[the manzo]

alright i will do that tomorrow

 

[Roadrunner777]

What's done is done. For future use, introducing cold water into a hot engine is not a good idea. Thermal shock leads to cracked parts. It is tempting to do whatever you can to make things normal again. In this case, the better move would be to let the engine cool to as close to ambient as you can stand to wait.

But, I have been there myself, and did what you did, so I am not schooling here. It's just, hot aluminum heads and cold water usually lead to bad things. Best of luck!

 

[IZwack]

For future use, introducing cold water into a hot engine is not a good idea. Thermal shock leads to cracked parts.
...
It's just, hot aluminum heads and cold water usually lead to bad things.

While that is possible, I'm going to have to say that it is unlikely in the real world for these reasons:
1) coolant is not added directly to the head/engine but rather to the reservoir - which means it will mix with the existing coolant already in the system (in the reservoir and in the engine)
2) off-road RBVs are driven into cold (almost frozen) bodies of water all the time. This includes the 4.0L SOHC which has an aluminum ladder frame at the bottom.
3) Aluminum (a highly malleable metal) has a lower Young's modulus than steel so it is less likely to crack from extreme thermal gradients than iron/steel.