I had heard from some people to replace the radiator every 100k miles as a form of maintenance. I didn't heed that warning and the radiator popped at ~150k. I was on a bridge with no shoulder and had to limp it almost 2 miles before I could shut it down. Never did see the temps get up there to say it overheated but apparently it did it's damage. Fast forward a couple months (the GX is not my daily and doesn't see many miles) and I now have coolant in cylinder 3. I was getting a misfire code for cylinder 3 which is what led me to this diagnosis. Anyhow, I have been cautioned by a couple friends who are mechanics not to do a head gasket job on this motor due to the small tolerances for error in making sure everything is in spec because I could be doing it again shortly. I got a quote for $6k for the HG job, $8k with timing chains and guides or likely somewhere in the $12k-$15k range to replace the engine. It would make me sick to try to sell it as is or part it out (I don't really have the time or room to part it out) and I am not in the habit of taking $6k-$8k rolls of the dice so I am likely going to replace the engine. In the meantime, we bought a 2017 IS200t to drive while I search for the replacement. On a side note, the IS is super fun to drive. 
So, I say all of that to say, replace those radiators BEFORE they leave you in a pickle on a bridge where you can't stop.
So, I say all of that to say, replace those radiators BEFORE they leave you in a pickle on a bridge where you can't stop.
