Is there a general mileage point that I Should consider replacing the thermostat and or water pump? I’m not sure if the ones on my current rx have ever been replaced and I just don’t know if I am on borrowed time or
not. I just don’t want to decide to take my car on a road trip and have myself get stuck somewhere due
to overheating because of a water pump and or thermostat failure

 

There is no "recommended" time to replace those items. All parts on you car are guaranteed to and will fail, it's just that we don't have anyway of knowing when.

I did a road trip and lost 2 ignition coils outside of Denver. Car couldn't do the mountains, so I had to get it repaired. But I don't believe in replacing parts just because they are old. Even new parts will fail, especially if they are made in China. So you get to flip a coin.

If you feel better replacing the water pump and thermostat, go ahead. I wouldn't.

 

My wife's 08 RX350's water pump had to be replaced at 98K miles when it start creating a rattling noise. My mechanic replaced the thermostat and belt at the same time. I strongly recommend using OEM part. My mechanic went with non-OEM thermostat and he had to re-do the job again with a OEM

130K miles on the RX now and no issue so far.

 

I understand not wanting to risk a serious problem on the road, yet at least one person took a 2008 lexus RX350 to 208k miles before the pump started showing problems:

https://www.clublexus.com/forums/rx-...er-pump-3.html

 

Yea I just called the shop I use for oil changes and some other things down the street from where I live to get a price on replacing both and when he told me how much I just about crapped my pants to say the least

 

Just changed the T stat on my 330 for peace of mind, water pump was replaced with timing belt last year. Only 83K on the clock. While parts are cheap, it is very labor intensive to get to the T stat although not rocket science, I can see cost being high but only cost me $30, coolant, and 2 hours.

If you change the T stat, OEM Toyota ONLY, do not even bother with anything else unless you can source whoever the supplier is for Toyota. A lot of garbage out there.

 

I bought the OEM water pump, Gasket, belt, Thermostat, 2 gallons of coolant online for $330. My long time mechanic charged me $220 labor.
Total out the door $550. That was almost 4 years ago.

 

U aren’t gonna believe what I was quoted for water pump and t stat replacement. They quoted me 1381! I just about made a oopsie in my pants after hearing that.

 

Wow. $1400 is way too high. That's like dealer price here in the SF bay area.