dkls400

So I finally got the LS on the road this past weekend. Everything was good until Sunday. I took it to the car wash and drove around a little in like 95 degree weather and once I parked it I noticed coolant was leaking out of the over flow tank by something that looked like a sensor. Once it cooled off and I drove it again everything was fine, until Monday. When the car is cold the overflow tank is empty but once you drive it around coolant comes into the tank and is boiling. The temperature is always at the middle. Any suggestions on what this can be? Thermostat? Fan? Blockage of some kind?

RA40

iTrader: (6)

Can you snap a pic of exactly where the coolant is coming from? How long a drive are you taking the car for?

The usual coolant drain, thermostat and reservoir cap replacement. If the reservoir is cracked, one of those.

dkls400

I could take a pic tom. Well the drive was maybe 30 mins. I think I'm going to change the thermostat see if that works. Do I pour coolant into the radiator or overflow tank?

dkls400

I wasn't able to take any pics but I got this one off the internet. Coolant leaks out of the circled cap while the coolant in the tank boils. Any ideas?

RA40

iTrader: (6)

I'm not familiar with the 1-LS. I suspect that area of the reservoir has a crack or damaged seal, thus the leakage. If it were overheating, the coolant would normally be released from reservoir cap and out through the hose.

python

iTrader: (4)

theres an o-ring that seals that sensor

steve2006

If it is leaking out there it has to be the o ring as suggested above, the system is not pressurizing due to the O ring not sealing the system and the water is therefore boiling,pressurization raises the boiling point of the coolant.
Replace the seal and you should be OK

Lexus part # 90099-14129 $3.13

Spend the $3.13 now as if left you may damage the engine through overheating.

dkls400

Okay, thanks a lot guys. Does anyone know what that sensor is called cause I think I might need the whole thing as it appears to be damaged.

python

iTrader: (4)

although ur correct about the boiling point being raised,the coolant mixture of 50-50 also raises the boiling point, so thats not an issue here,pressure is causing it to leak at the weakest point

dkls400

Upon closer inspection and the use of a flashlight, I found a small crack in the plastic near the sensor. I'm going to put epoxy as a temp. fix while I look for another reservoir.

V8drummer

iTrader: (5)

This is very common with both the sc400 and ls400. I'm looking for a reservoir right now as well for my SC. Just a poor design I guess.

RA40

iTrader: (6)

Glad this got figured out. Plastic on these aging cars is a PITA. I've had this with other plastic parts. Sometimes epoxy is great other times, not. GL

dkls400

Thanks for the help. I agree the old plastic will all soon be cracking, but hey comes with age.

Bill Dowd

I had to replace mine with a new one they aren't cheap but cheaper than a over heated engine i don't know if anyone makes one after market

flipmode64

Sorry to resurrect but is there a generic o-ring that can be used? Or could someone supply the dimensions of the real o-ring.

Unless someone can point me to one on ebay but can't seem to find a genuine one.

Lexus dealer is 2 hours away and they wont let Toyota order it even though the part number is good in there system