It's been about 7 months and 3,000 miles since my radiator replacement. I noticed this morning that the coolant level in the reservoir was close to the bottom but still visible. I'm aware of all the threads on this forum with regards to watching the coolant level and filling when necessary. The reservoir itself does show the white/reddish stains on the outside which is quite common. I added about one full cup 18-20oz of the long life factory red coolant/distilled water mixture The LS430 is the first car I've owned that needed to have coolant replaced periodically. Even my 04 G35 after 10 years of ownership never needed a drop to be added. I'm sure there a many members on the forum that don't even check the reservoir, but they should.

 

Kind of surprised that not one member decided to look at their reservoir to notice low coolant and report back.

 

While checking oil today, I took a glance at the reservoir coolant level, and it was about 2 inches above the reservoir bottom. I filled it up with Toyota red+ water to full level. Maybe 10 ounces or so. I filled it up after I did the timing belt / water pump jobs about a year ago. Maybe some air left in the system then.

 

Nope... sorry.. our cars lose coolant. Can't fight it.. Just something to watch and replenish. when needed.

 

I didn't see this thread earlier but I checked my reservoir the night I did my interior led upgrade. I was putting the last two wedges in the headlights and decided to open it up. The radiator was find but the reservoir was pretty low. I just added some for good measure. No signs of crust or leaks.

 

one of the clips that hold the cowl on was missing, Lexus did not have one in stock, but ordered a 90467-08155 and it should arrive in a few days. cost a cool $1.78. if it is low I will just top it off with bottle water, not buying a gallon of coolant for a few ounces.

 

Evaporation over time and also maybe a little air in the system after replacing coolant... It happens.

 

Hade mine 04 for almost a year now. And it gets really hot hear, easily 95-100 degrees in the night. Never got low coolant. Topped it once Checked it like 3 times.
Recently did the timing belt, pump, radiator at 150,000 and all is good.
But as the reservoir is not pressurised I fuse you get more evaporation with heat cycling.

 

I had my oil changed today at the dealership, and the service writer came to me and said the coolant overflow tank was low, but not empty. He said the tech thinks it may need a water pump, but at this time just watch it and replenish as needed. From what I've read here, these cars tend to loose coolant over time, so I'm not too concerned.

 

The tech is assuming that the WP may be slowly leaking. You're correct, the overflow reservoir does lose a little over time, but if you measured the volume, it is only a few ounces.

 

If your water pump was leaking (even slightly) causing the low level in your reservoir, you should most likely see at the front of the engine compartment white dots on the hoses and other parts. If the coolant was leaking it would get blown around the compartment and not necessarily be seen in one location. If it was a more severe leak, you might see it on the floor or bottom pan, but that should certainly show up quickly as a low or empty reservoir.