ll technically there is nothing wrong with it . just make sure you put i back in as he ecu uses water temp as a metric for fuel / air timing
I have done it on cars
Another thing you may want to consider is a product called RMI -25 it slowly cleans the engine and deposits it in the over flow tank
used it on my last three cars my recent 1999 Acura was the first one that did NOT leave anything in the tank ..
I am installing some tomorrow in the FJR