The coolant reservoir is getting close to the add mark.

Does the top-off antifreeze need to be purchased at a Lexus/Toyota dealership?

TIA

 

Just mention it to the service writer next time you are at the dealership and they should take care of topping that off for you. No reason to purchase a gallon when it is not needed.

 

Make sure you check it when it's warm. When it's cold, it will be closer to the add mark. But if it really is low, like bill said, get it checked.

 

I thought the dealership would top that off (if needed) when you go for an oil change? My Toyota dealership does.

 

My question to the dealership would be -- where is the coolant going? A cooling system on any modern car is a closed system (or is supposed to be) that should never need "topping" up. The coolant can't evaporate, the engine doesn't "burn" it and the only way the level will drop is if you have a leak.

I don't allow leaks in my vehicles. It took almost 2 years of visits to my Porsche dealer to solve one on the Cayenne that only leaked about 0.5oz per month - but I could smell the coolant and that bothered me. Thanks to CPO warranty and a determined service manager - they finally tracked it down to a small porous spot on the rear of an aluminum coolant manifold between the two banks of the V8. It now doesn't need "topping up" and I no longer smell coolant.

Leaks rarely fix themselves.. if you're under warranty bug your service department and tell them that losing coolant is unacceptable.

 

How did they fix it?

 

Check for any leak around the water pump area.
2011 and older models have issue with the water pump.

 

The coolant has some water in it, so it can evaporate-many manufacturers now put only as little fluid as need not to trigger warning light. SO if even minute amount evaporates the level is down to minimum mark...

 

Dealer just did oil change; I was checking fluid levels and noticed low coolant.

Appreciate the comment, I will inquire if they will top-off.

 

They replaced the casting that went between the two cylinder heads. Not an easy job - it was sort of wedged between the rear of the heads and the firewall, and had a lot of other plumbing and sensors attached to it.

Since then - no smell, no leak, no adding coolant.

 

It could only evaporate in an open system. A pressurized system should never release any vapor to the atmosphere unless the vehicle overheats. That's part of the reason for a pressurized system, and the coolant reservoir tank. In the rare periods when something coolant related isn't leaking on my BMWs, I'll go several years with the level never changing. If it does start to change, it's time for me to look for the leak, and I always seem to find one.