Hey Scotty how are you doing? I am a daily viewer of your videos on YouTube much to the chagrin of my wife however I come to you today with a question about my 2015 Lexus ES 300 H hybrid four-cylinder. I bought the car in 2018 it had 25,000 miles it currently has 234,000 miles are use it for my ride share business. So far the only thing I have had to do on it is replace the front wheel bearings. Except for the water pump which I just replaced all by myself (aren’t you proud parenthesis). While I was doing the water pump I figured it might make sense to do the thermostat as well so I did both of those let me tell you it was a heck of a job and my hands are pretty scraped up but I saved several hundred dollars doing it myself versus bringing it to a local mechanic. So far the problem with the intermittent overheating and simultaneous loss of heat in the cabin has not returned but I am noticing that the lower radiator hose is not warming up even after driving the car more than 100 miles. I’m pretty sure the water pump was the problem because I dismantled the old one and found that one of the parts of it had swollen and it was very difficult to spin with my hand compared to the new part. So what do you think about the lower radiator hose is it possible that there is a clog in there or that the thermostat is defective? The other thing I noticed when I took the lower radiator hose off from the thermostat was that there was some creamy looking fluid there as well as a little bit of coolant that came out do you think it’s worth detaching again and trying to flush the radiator / check for a defective thermostat? So far it’s running normal like it was before the overheating issue there is more to the story as per probable bird visit to the dealership but I don’t wanna bore you with the whole story ha ha Ha have a great day thank you so much! Robert
So far everything is much better than before, radiator cap is much cooler after a day of driving, and the delivery of heat inside the cabin is greater and more consistent. I’ll keep an eye on everything and once the weather gets hot if the lower hose still stays cold then I might try testing the thermostat and flushing out the radiator. Go from there.
When you refilled the system with coolant, did you go through the proper burping procedure to get the air out of the system?
Yes, system is burped and after 10 highway miles the heater is blasting super hot.
I would just make sure you bled the system properly and I’m not fully aware of that’s a thermostat unit or just a thermostat. If it’s just a thermostat it’s possible it’s not indexed correctly. Generally speaking the small hole should be at 12o clock
It’s a thermostat unit. I think you’re right, it was probably like this before changing parts. I will keep an eye on it and if it seems to start running hotter than usual then I might try flushing the radiator, and testing the thermostat and go from there. Unfortunately after completing the job I tested the original thermostat by placing in boiling water and it did seem to be activating correctly.
Just an update everything is still going fine and it’s been a solid 25,000 miles since then. I have even been operating in some pretty hot weather. Also I put the car into maintenance mode and let it run for 20 minutes with the air conditioning off and the lower hose did get hot it does not get hot with the air conditioning on because with the air conditioning on the fans run constantly.
Thanks for the update.