Hey Guys my coolant was right below the low mark (it was right above 1k miles ago so it has a slight leak, but haven't checked the bottom core yet, most likely its leaking there?) so overnight it sat and in the morning ive filled it to the high mark and upon starting and warming up the engine the coolant went back to right below low. It doesn't look like its leaking at least not anywhere that fast, is this normal? I gotta check later again while car warmed up etc to check level, but how can the coolant go from being at the high mark to right below the low mark?

Regardless the radiator had previously been repaird by the lexus dealership for leaks, where it should've been replaced. Luckily lexus said they will take a look and replace, but Id rather not go through the dealership.

Can anyone explain the high/low level mark?

 

When you fill in the coolant overnight, was the engine already cold?

 

Sorry, meant the car sat overnight and in the morning the fluid was right below the low mark, it was refilled to the top line in the morning after sitting overnight. Upon starting the car up and getting to temps, it went back to the low mark?

yes it was cold when I added the coolant to top line.

 

ahh maybe it was the radiator that was low on coolant ill just raise the car up and check for leaks myself then escalate or maybe the system wasn't burped right by the prev mechanic.

 

these cars are known for coolant leaks. If its an 08-09 could be the water pump. If its later it could be the valley plate in the engine leaking. Mine has been this for years. No leaks found. I just bought a bottle of Toyota Super long lasting coolant and add some every 6 months.

Its nuts because for it to go from high to low is like 4mls-6mls. Its not a lot of fluid. When they do the recall campain they will find the leak and repair. Or at least it seems like thats what happening with the other members

 

cool ill add some more today, gonna also check for leaks to see where the issue is.

 

I bought the Toyota coolant on amazon for pretty cheap. I check it once a every couple of months. Its funny how little you will need to add to make it go back to the high line. Like seriously less than 4-6mls

 

I basically have the same exact issue. The coolant was below the low mark. I waited overnight, added distilled water til the level was right under max. Went for a drive and checked the level (while still hot), and the coolant was under the low line again. From my understanding the coolant and pressure should expand while hot, not shrink.

From what I can see (overhead view), there's no leaks in the typically areas: waterpump and valley plate.

Another thing that is slightly worrying is that even after I've left the car for a few hours, the water temp gauge on the dash still shows the temp at or close to the operating temp, whereas the oil temp has long cooled down. I've checked the radiator and don't see blockage from leaves or gunk. I'm wonder if the low coolant isn't a contributing factor, if my sensor might be going..

 

Alright, follow up to the post above:
I decided to be safe than sorry, and take my car to the dealer. They found that I had a leak at the valley plate. I couldn't see any leakage when I checked, but apparently it was there. Not surprised seeing as how the coolant level was low, even after I added water into the reservoir. Luckily I'm at 67.5k miles, which is under the 70k powertrain warranty. I suggest everyone keep an eye out on your coolant level before your warranty is up. From my research It's looks like a pretty expensive fix.

Notes: MY2011 @ 67.5k miles

 

Hey KZ yeah I havent been trolling here in awhile lately due to being busy with other stuff more important. I got your pm and I was going to tell you it was leaking from valley plate which isnt really visible from the top had to go under and look around the transmission casing to find the leaks anytime I filled it up on coolant.

Hopefully you took it to Eric at Riverside, that guys golden.

 

Nope, I took it to Longo. Didn't have the time and didn't want to risk driving all the way to Riverside, since I live in the 626. Took it to Longo instead. I'm sure they'll do a good job