2007 ES350 Coolant Flush

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Jun 4, 2026 | 06:08 AM

June1978

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From: MD

2007 ES350 Coolant Flush

Getting a coolant flush done this weekend. Should the thermostat be swapped out to for maintenance purposes? My tech said no need.

Jun 4, 2026 | 07:30 AM

LeX2K

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From: Alberta

Thermostat is mileage dependent, plus how many heat cycles it goes though. Around 150,000 miles is when I consider replacing it. Never use anything but a genuine Toyota part 90916-03133 here you'll regret it. Hope your tech is using Toyota Super Long Life coolant not some generic "good" enough product.

Jun 4, 2026 | 08:08 AM

June1978

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From: MD

Quote:

Originally Posted by LeX2K

Looking at the Lexus records, it's never been replaced. Previous owner only took it to the dealer up until my ownership starting in 2021. I have the genuine part but he said leave it alone. If it's not causing issues, no need to replace- but I'm at 240k

My tech is a Toyota guy who works at the dealer. Does side work here and there. Basic maintenance stuff like oil, fluids, brakes etc....nothing major.

Jun 4, 2026 | 08:22 AM

LeX2K

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From: Alberta

That's an impressive run for a thermostat.

Jun 4, 2026 | 09:31 AM

June1978

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From: MD

Quote:

Originally Posted by LeX2K

That's an impressive run for a thermostat.

Yeah, if it's been replaced, there's no record of it. and I don't know how to tell. I'll leave it alone for now.

"if it ain't broke, don't fix it".

Yesterday | 07:32 AM

Quinten

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From: NV

Quote:

Originally Posted by June1978

Yeah, if it's been replaced, there's no record of it. and I don't know how to tell. I'll leave it alone for now.

If engine coolant temp comes up to normal within a few minutes and stays there (steady) while driving it is functioning properly. If it takes longer than a few minutes to reach normal operating temp, then you would want to replace it.

Yesterday | 10:20 AM

June1978

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From: MD

Quote:

Originally Posted by Quinten

Yes, it's working normally.

My gauge is almost at the half way point- maybe a few millimeters before the midpoint. I don't think it ever sat exactly in the middle.....