Burning Coolant?

[Imzjustplayin]

I've got an LS400 '94, 123K miles and I was looking at the coolant reservoir and noticed that it was very low. The car hasn't been driven in a while but I do remember last year noticing that it was low on coolant. I washed the engine bay with a hose about a week ago because mice were hanging out in there and I didn't want to vacuum it for fear of getting polluting the air and then getting sick so I got it wet and washed sprayed it. Anyways when I pushed the car back from its position when washing a few hours later, I noticed what I believe to be oil on the ground. My belief is that this is the power steering fluid since IIRC the powersteering has been leaking somewhat, I don't know if there was coolant in there or not.

To sum it up, I wanted to know if coolant can simply evaporate from the engine with out there being any sort of leaks or not. The car was parked last year and the year before in the hot sun so I was hoping this was the only thing that would cause the coolant level to be so low. The reason I'm asking is because I read that you can be burning coolant and not even know it, though if the tailpipe has white smoke then the headgasket is bad or there is water in the engine for what ever reason.

[TA in KC]

A headgasket failure is extremely uncommon for the 1UZ-FE engine. It is not unusual to see the coolant level change based on temperature, both of the coolant and outside, because it expands/contracts based on temperature.

[Imzjustplayin]

A headgasket failure is extremely uncommon for the 1UZ-FE engine. It is not unusual to see the coolant level change based on temperature, both of the coolant and outside, because it expands/contracts based on temperature.

Well the coolant level is about 3 inches below the "cold" level, only sightly higher than the line going from the reservoir. I just don't understand why it'd be low on coolant yet I see no indication that it's leaking coolant. You're probably right though, the headgasket should be fine considering I've never run the engine hot and I doubt my mom did either.

[TA in KC]

A headgasket failure is extremely uncommon for the 1UZ-FE engine. It is not unusual to see the coolant level change based on temperature, both of the coolant and outside, because it expands/contracts based on temperature.

Well the coolant level is about 3 inches below the "cold" level, only sightly higher than the line going from the reservoir. I just don't understand why it'd be low on coolant yet I see no indication that it's leaking coolant. You're probably right though, the headgasket should be fine considering I've never run the engine hot and I doubt my mom did either.

Save yourself all the anxiety and do not even think about the headgasket. If you had a problem there, you would know! You can always add more coolant if the level does not go up when the outside temperature increases. Remember that the tank is an overflow tank, so when it gets totally full it will just drain out the extra coolant by itself.

What does the level look like right after you have shut off the engine?

[NewGuy19]

I had a similar problem with my car loosing cooant while it sat as well, however it wasn't for nearly as long of a time. It was the middle of the North Dakota winter and right around 0 outside. So I knew it wasn't evaporating from heat and there was no visible sign of it dripping on anything. It turned out to be the water pump which was on its way out. I still don't know where the coolant went that was in the tank. But the problem stopped after I changed the pump.

[Step Hen]

The coolant system is a sealed system so you will not have have the coolant just evaporate.

You'll want to look out for white residue around the engine bay and under it as well as that is the tell-tale sign of a coolant leak.

[90LS400Lexus]

I have never heard of coolant "evaporating" in that amount of time. I have a 1989 Pontiac that I have not driven in about 4 years and every winter when I check the coolant level its always full and at proper protection.

I agree with Thomas- headgasket issues are virtually unheard of on the LS400's.

Its just too bad that Toyota did not use the same quality of headgasket on the 2nd generation Toyota 4-Runners/trucks and Toyota T100, Cressidas and Supras (older models), as those are Toyotas that have been plagued with headgasket issues. Too bad because those are otherwise excellent cars.

[Imzjustplayin]

The year before I changed my oil to full synthetic and I'm wondering if this could be the cause of this. I washed down the engine bay two months ago and I saw coolant and oil on the ground where the car was when I was washing it which confirmed my belief that it was leaking coolant. As for the oil, I believe it's the powersteering fluid since residue can be found near and around the reservoir which implies it's leaking.

[90LS400Lexus]

I'll eat my own words... here is a LS400 advertised with a bad headgasket..... <_<

http://asheville.craigslist.org/car/762629569.html :o

I have never heard of coolant "evaporating" in that amount of time. I have a 1989 Pontiac that I have not driven in about 4 years and every winter when I check the coolant level its always full and at proper protection.

I agree with Thomas- headgasket issues are virtually unheard of on the LS400's.

Its just too bad that Toyota did not use the same quality of headgasket on the 2nd generation Toyota 4-Runners/trucks and Toyota T100, Cressidas and Supras (older models), as those are Toyotas that have been plagued with headgasket issues. Too bad because those are otherwise excellent cars.

[vroom8]

water pump?

[chilkoot]

HCV, heater control valve. It leaks slowly enough that it could seem to be evaporating, and will not leave puddles on the ground. It'll cost about $60 on LPO, it's located on the firewall behind the throttle body.

[Lexusfreak]

How old is the coolant in the car now? This might be a good time to do a full coolant flush (like $60 - $70 & I would use OE coolant this time around with a jug of distilled water you can get at your local supermarket for less than $1) & monitor things.