I have a 2000 Lexus es300. I have been experiencing some severe overheating issues. My oil looks clean and great and I have no steam from the exhaust, but I did do the combustion gas leak test and the gases are getting into my coolant. So, I have a small head gasket leak like I have never seen before. It is just boiling the coolant out of my system. Getting ready to replace the head gaskets in the car and I'm not looking forward to it. Is this a common issue with the 3.0?

 

No not common it takes a severe overheat to damage the 1MZ-FE. You are better off finding a used engine than trying to repair yours. If the heads are warped the tolerance is extremely small meaning very little material can be removed. If too much is removed it changes the cam timing and the engine will never run properly.

 

I forgot to post an update. Shortly after my above post, I did a coolant leak into exhaust check, which revealed a small head gasket leak. I disassembled the engine and repaired the problem, while performing several maintenance items while it was down. That has been almost 6 months and several thousand miles ago, and it runs like new. Thanks for your reply.