The car has been running warmer than usual. On acceleration the temperature gauge will move up to the three quarter mark. When I cruise it goes slightly over the half way mark. When parked it will run and the engine temp does not move beyond the half way point. I came back home today and I could hear burbling sounds and I could see coolant running down my driveway. When I took the radiator cap off there was no coolant and the overflow tank was empty as well. The cooling fans have been running a whole lot.
Any ideas anyone? Thank you in advance. It is a 2005 LS430 Ultra with a 209k miles.
Before I replace the thermostat I want your advice and opinions as to what could be going wrong

 

Don't run the car hot. Get it checked out right away. Sound like you are loosing fluid somewhere if your radiator is empty. First look for leaks and corroded rubber hoses. Fill her back up with the correct coolant before you drive. Might need to bleed the system if air gets in.

 

It boiled over in my driveway. Hence loss of fluid. Thanks for the tip.

 

Yeah. That would make sense with it boiling over. Did you have fluid in the reservoir before it overheated? Could be as simple as a bad radiator cap.

 

My 2001 ls430 did this and the problem was a bad radiator.
The radiator is plastic around the top and separation is a fairly common problem.
fill it with water and look for a leak.
If not, probably sounds like a thermostat.

 

Get the system pressurized and look for the leak.

 

It had fluid before it boiled over. It has been dry today was the first time fluid came out. It has been running hotter than usual. On acceleration up hills the gauge will move past the middle to 3/4 and then if I am coasting or stopped it goes back to the middle. But the fans are running like crazy. The engine did not over heat. There was burbling sounds and then the coolant ran out

 

Put at least some water in while you drive to the mechanic. If it gets close the red pull over otherwise you will probably blow a head gasket.

 

That is the funny thing. It never goes above the 3/4 mark. It is in my garage. I travel on Thursday. When I come back I will attend to it. I ordered a new thermostat. I will put it in and see if it makes a difference

 

Were you able to see what part of the radiator was spewing coolant? Was it coming out of the overflow container?

It could be several things, something as simple as bad radiator cap can not allow the cooling system to keep itself under pressure and all your coolant boils over into the overflow.

Regardless, with over 200k miles, I would replace both the radiator cap and thermostat anyway. But it could also be a leak in your radiator, some Lexus have issues with the plastic tanks separating. I had to replace one on another Lexus at around 90k miles. But usually those leaks are much slower and gradual.

But be careful not to drive around with a cooling issue, that can turn a simple repair into blowing your head gaskets and thousands of dollars. If your not comfortable with your DIY skills or diagnosing it, take it into a shop and they can put the system under pressure and easily see where the leak is coming from and why.

 

It was coming from the over flow hose. The car is sitting in my garage. I have odered a new thermostat and gasket. I will replace it as soon as it gets here. I will order a radiator cap or go to the Toyota dealer and pick up one. Thank you.

 

if your mechanic told you your radiaitor cost 5 grand, then he must be ripping you off . find yourself another mechanic

 

Denso OEM is only $116 on Rockauto.

 

Be smart with this. At 200,000 miles you should expect to do a little maintenance.

1. replace the radiator. There cheap and easy to do. The one you have is not holding pressure.
2. replace the radiator hoses. Easy and cheap.
3. replace the coolant. Also easy
4. replace the thermostat. They do not last forever either.

Better hope you did not already lose a head gasket.

 

^ This with some contingencies:

If the cooling system has been regularly maintained with the right coolant and distilled water, the likelihood of deposits is lower. Do the simple stuff first by replacing the thermostat, reservoir cap and fresh coolant. If there is leakage from the radiator tanks, you'll see the deposits in most cases.

With a spray bottle filled with water, spray water around the tanks, radiator fins and look to see if it drips reddish water. If so, there is a leak and the radiator is going to need replacing. If replacing the radiator do the upper and lower hoses too. If you can pressure test it even better. I've used the water spray bottle on many occasions to check the radiator and this has worked for me.