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iTrader: (3)

okay i have a 1994 lexus gs300 and it keeps reading high temp past the half of the temp gauge, i replaced the headgasket, waterpump looks new plus it flows the radiator very well, got a new radiator cap, new radiator lower hose, radiator is not dropping any fluid, took out the thermostat, i just dont know what it is anymore can someone help me out?

tuner79

I'm having the same problem and it's driving me nuts! Now the car idles at 500rpm then dies. Whenever (cold or warmed up) I turn the key the temp gauge goes straight up to the top. I replaced the thermostat, water pump, temp cooling sensor, cooling temp gauge, upper & lower radiator hoses, & flushed the radiator. And this $#!+ still reads that it's overheating. What gives? I just dropped this motor in and already replaced the headgasket. No coolant is leaking into the block. Please someone help!

Aristoman

iTrader: (1)

when you replaced the headgasket did you send the head to the machine shop to get it resurfaced and check if it was warped? what head bolts/studs did you use?

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iTrader: (3)

everything was done professionally by my friend which is a certified mechanic and i know he sent the head to a machine shop

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iTrader: (3)

the car reads high but does not over heat, i run the a/c on max and still does not over heat im like what is going on, i heard something about the harmonic balancer could this be it?

Is300Tree2

Try unplugging the coolant temp sensor and run the car. I dont know what else it could be. If its reading hot maybe you have air in the system. Try to also top it off. Run on hot at full blast and then top it off after that.

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iTrader: (3)

where is this sensor located? and i done the whole blast the hot air and top it off so?

tuner79

The sensor is located beside the upper water neck under the intake manifold. Mine was color coated (green for coolant). The sensor should cost around 22 w/tax. At least that's what I paid for it. If you do decide to replace it then you'll need a 19mm deep socket. Be sure to disconnect the negative batt terminal. I had to rip the sensor off the nut in order to loosen it properly. The 19mm does fit over the sensor on to the nut it's just that you can't get a sufficient grip and the socket just slips of increasing the chances of stripping it.

tuner79

Oh and don't forget to put a pan under the motor. You will leak some coolant.

Aristoman

iTrader: (1)

so when the Gauge reads High is there any coolant bubling in the coolant tank? if not then it might be your coolant sensor as mentioned above.. you might as well replace it.. its pretty cheap. i remember getting one for 30 bucks or something from napa

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iTrader: (3)

yeah dude nuthing is boiling i will definitely replace and post up the results ok thanks guys so far

tuner79

I forgot to mention. When my sensor went out the car went into a kind of safe mode. I couldn't put into gear. So that is one way of telling it's the sensor. It mentions something about the safe mode in the service manual.