ChrisSC300

I was driving around tonight and on the way home the temp. guage went up like 75% up the scale. luckily i was in my drive way when this started happening. So, i popped the hood and steam was everywhere including on the outside nose of the car. And there was radiator fuid (it looked like it) all around like it had sprayed out the radiator cap. So I looked at the radiator fluid level and it was almost full, and all the hoses seemed fine. What in the world could be wrong. I have work tomarrow and as of now i dont have a car. Any idea's. Thanks.

akmpres

did the fan fail? one of the hoses might have a leak., i dont know much but i had a Caddy STS and the fan went and the same thing happend, good luck!

pcmw

Well simple deal...

Car cooling systems work on a basic principle.

They run coolant/anti-freeze thru the engine.

However, engines get hotter than the boiling point of the coolant, or water. Hence they boil over causing the steam you see.

So... with that said.... to not have the fluid boil over all day long, the system is pressurized. Fluid under certain levels of pressure DO NOT boil as easy as base pressure.

Your system has lost pressure and/or is not flowing THRU the engine.

TWO things control this. #1 Flow is maintained by a thermostat. This has to open and close for flow. #2 Pressure is maintained by the radiator cap. This wears out over time losing pressure.

SOOOO...because the thermostat is harder to change. Start with the radiator cap. Wait till the car cools down, and is not steaming. Then touch the radiator cap and make sure that it is cool to the touch. Then remove it... take a different car to the autoparts store and get an identical replacement. (they are based on the pressure number... I think .9 for our car). Bolt it back on, squeeze the radiator hose to insure that fluid is flowing again and start it up.... it may take 30sec for it to start flowing under pressure again....

If this doesn't fix the issue and your fluid level does NOT drop then your thermostat is stuck shut and you will need to purchase a new one for a few bucks.

Good luck

ChrisSC300

Thanks for the help. I am thinking it is the thermostat since i was driving around for a good hour before this started happening. Anyhow, about the thermostat. What kind of job is replacing it, a do it yourself or a dealer only kind of deal. And how much do they cost and where could I pick one up. Thanks again for the assistance.

pcmw

Okay...this is easy but you will need the following.

Gallon of Coolant.
Socket set.

Part 15 and 14 below. about $15 from Lexus

To change the thermostat just unbolt it...replace it and bolt it back.

To add the fluid back into the car... start with the radiator cap off...watch for it to boil and open up the thermostat gate... then the level will begin to drop in the radiator. As it falls, add coolant to replace what boiled off or fluid that you lost changing the part. Be sure to get all the air out of the system and you are done.

wwest

You said you were (setting{?}, with the engine and A/C running{?}) in your driveway when the gauge went to 75%

As you were driving around the natural airflow from your forward motion was providing (unboosted) cooling capacity for the radiator. Once you stopped the electric cooling fans HAD to be working are the car would overheat.

But then you're in JAX... HOT and humid even in the evenings, may have been an unavoidable natural occurance. The SC engine cooling system may not have the capacity to cool the engine at idle with the A/C running full blast.

Oh, just remembered, 92 SC, at least one of your radiator cooling fans is run by the hudraulic pressure from the power steering pump.

jewelerz

Is that same fact true foe a 93 es300? With the cooling fan being controlled by the power steering pump/

Qmanlexus

There is no electric fans in the SC300. To me it sounds wike the Thermostat is hung up. I am getting ready to replace mine. Thanks for the diagram showing the O ring gasket and thermostat. Also the question I have is how after you change the antifrezze how do you purge the system to get the air out? is there a way of doing this?

VSsc400

iTrader: (1)

Here is what I would do

1.change radiator cap
2. change thermostat (I replaced mine with a non-lexus generic brand but works fine)
3. Visually examine hoses and water pump for leaks and replace as necessary
4. do a radiator flush

If still overheating you may have to replace the head-gasket

I beliver the 2 bolts thats holding down the thermostat is either a 10mm or a 12mm socket.

radiator cap $8 @ autozone 1 minute job
thermostat $15 @ autozone 10 minute job
thermostat gasket $4 @ autozone
gasket sealer $5 @ autozone
radiator flush @ lage lube(or shop of your choice) $50 (make sure they use the red coolant)

before doing anything make sure that everything you work on is cool to the touch.

wish you luck. please posts results.

Qmanlexus

VSsc300 Thanks for the Reply . how do you purge the system to get the air out. I read somewhere on how to do it.

VSsc400

iTrader: (1)

thats VSsc4 00 but no matter. I didn't do the purge myself but the guys at the lube place did it for me. They had a special pump to suck the coolant from the reservoir instead of just draining it purging the system of all the air. For those around NY aread I went to Lage Lube in Whitestone.

I'll be around Queens area this saturday getting my brakes done so if you want to meet me give me a call and I'll take you to the place. I'm in there alot since I drive about 30k miles per year so the guys know me so they treat me pretty well.

Dennis
917-902-4261

Qmanlexus

VSsc400 sorry about that. I wont be able to meet you because I have to go to a funeral on Sat. Maybe next time. I will give a call soon I am out on Long Island. Again thanks Info and quick reply.

VSsc400

iTrader: (1)

I am always in queens on saturday so if you need anything gimme a buzz. I also got a guy that I go to that does great work. I used to go to the dealer to get my car serviced but not this guy does all my work and I've been never let down and great prices.

Hermosa

You can get dual electric fans in your SC300 for $259 from PowerHouse Racing. Some say it is a better performance mod than the S-AFC. It frees up low end power.

lex400sc

Electric fans have their benefits, but they are more likely to fail. And when your fans fail, you're screwed