2009 Lexus RX350, it failed the pressure test but we still couldn’t figure out where the leak is. He tested the head gasket it came back inconclusive, we can look into this further but it’s going to be even more expensive. It’s not in the oil, there’s no white smoke, I haven’t noticed external leaks, not in the transmission fluid either.
First started a little over a month ago when I noticed the reservoir was empty when we were traveling. We decided to do a radiator flush and bled the system then continued to check it until we could make it back home to the mechanic. It never leaked again and he told me to just take it home and keep an eye on it. Yesterday I went to check the coolant for the first time in 3 days (I haven’t driven much) and the reservoir was empty and the radiator is super low. I’m going to refill it and take it in but I’m unsure what the issue could be and where this could be going?? Anyone have other ideas to check?
There is a metal coolant pipe that connects to the water pump with an o ring, and the pipe then runs under the intake manifold through the intake valley to the transmission end of the engine, where the pipe connects to coolant hoses. These can leak there. You might, possibly be able to check for dried coolant residue at the transmission end of this pipe, but it’s gonna be really hard to see without removing the intake.
A blown head gasket is also a very real possibility, it should be detectable by pressure testing the system.