Coolant level dropping

[Leo99]

Originally Posted By: SatinSilver
Not that it's related but doesn't this car make a ton of noise while driving? Like a bad wheel bearing or something.


No. Drives real nice. No noise other than the occasional transmission clunk.

Pressure hold complete. Pressure held. Pressurized the radiator to 16psi. 5 minutes at 16psi.

Note: wife drove home in 85°F weather and the overflow tank was not at the hot level; just a little above the cold level. It's usually at the high level. Don't know if that means anything. And the weak air conditioning is now no air conditioning. Just blows warm air.

 

[Leo99]

Got it real hot last night and pressured it with the thermostat open and got a drip on the floor. It's coming from the back middle of the engine. Probably is a head gasket. Put some K-Seal magic potion into the radiator this morning. My wife wants to wait until October so she can buy a 2018 model Rav4. Fingers crossed. I think I can nurse it along until then.

 

[Leo99]

Looks like the problem is solved. It was a bad radiator cap.

 

[udidwht]

Originally Posted By: Leo99
Got it real hot last night and pressured it with the thermostat open and got a drip on the floor. It's coming from the back middle of the engine. Probably is a head gasket. Put some K-Seal magic potion into the radiator this morning. My wife wants to wait until October so she can buy a 2018 model Rav4. Fingers crossed. I think I can nurse it along until then.


If it's the backside of the engine block (firewall side) then the engine block thread issue is likely. With 300K on the RAV 4 I'm leaning that the gasket is the issue not the engine block threads. The issue relating to the threads was occurring the majority of times with engines that had less than 150K on the OD.

I repaired mine on my 2003 Highlander 2.4L with 198K on the engine when it happened. The engine now has 235K and is running great. I also replaced water pump, radiator, T-stat and sent the head out to be rebuilt. The fix is not for the novice. Once repaired it will be stronger than it was when new without the thread issue. The old threads are drilled out than time-serts are installed that allow for greater thread length the OE had. The OE head gasket has also been modified to be much more robust than the original one.

The 2AZ-FE engines are remarkably reliable when the issue isn't present and the engines have historically been very robust easily achieving 500K+ miles if maintained.