This is a little ridiculous but need a little advice. 2024 gasoline model.

Noticed today the engine coolant reservoir is below L. Ok will add some.

Open owners manual. Tells you to check coolant then says if below L to add coolant, procedure on Page 485.

Turn to Page 485. Remove engine cover, then open BOTH engine coolant caps (there is one on passenger side then one on top of the engine). Add coolant to passenger side reservoir until at “F” then put the cap back on the tank. Then fill up the other cap until full and then replace the cap on top of the engine.

All makes total sense. No problem.

Remove both caps…. Coolant proceeds to drain into the passenger side reservoir. I can hear it gurgling. Passenger side reservoir is now way way over the full line.

So my question… I think I need to siphon some out of the reservoir and then add coolant to the cap on top of the engine? Or can I just let the engine run and when the thermostat opens, the coolant will cycle and all is ok?

My biggest concern is that I’ve heard you can get air pockets in engines if you don’t flush things correctly and that can damage the engine.

Suggestions?

Clearly I probably should have just added a little more coolant to the passenger reservoir and called it a day. But no… you decide to read the manual and this happens

 

Well decided to just siphon out the excess from the passenger reservoir, down to the F line. Then put the cap on.

Then filled the engine fill to the top as the manual says. Capped that.

After test drive I’m a bit above full in the reservoir now. Hopefully all good.

 

Isn't it irritating when no one acknowledges your post?

Have no info for you but at least you know someone read your post.

Glad it worked out for you.

 

I always add coolant to a car engine that is completely cold. I don’t recall an issue with overfilling, however I usually stop filling when the level is just slightly below the full mark.
Why was your engine coolant level low? I always check my garage floor for coolant or oil leaks. My 2020 LS500 had a leaking water pump at 38,000 miles. There was pink residue around the water pump. You can inspect the water pump at upper right front (passenger side) of the engine if you remove the engine cover.
The coolant reservoir on the driver’s side of an LS500 is intercooler coolant.

 

2024 model year low coolant goes to the dealer to top off and record the incident.

 

If is very low, you have to bread the system. but first you find out way happened. It's not normal.

 

I'm not sure if it was always this way or not. I don't think I ever looked. But had an oil change the other week so wanted to check the dipstick and figured while in there I'll check the coolant level.

Plan to monitor at this point if it drops from here.

Thought about going back to dealer but it is 1 hour each way...