Lexus ES 300 over heating

SHANNEY1

MEMBER
1994 LEXUS ES 300
6 CYL
2WD
AUTOMATIC
160,000 MILES

I have a 94 Lexus ES 300, I have been having a problem with the car over heating. I have started the process of elimation by replaced the radiator which is after market not sure if that makes a difference. Water pump has been replaced, there is no thermostat on the car, power steering pump has also been replaced. I was told that this car has a hydratic system so the radiator, fan and power steering is all connected and run off each other and my rack and pinon is out so could this be a problem of why my car is over heating from the back pressure?

5 Replies

RIVERMIKERAT

MECHANIC
6,110 POSTS

Verify that the power steering reservoir is properly filled. Next, verify that the fan turns when the engine is running. Bypass the engine coolant temperature sensor to "hot wire" the cooling fan.
The system is hydraulic, so the fan is operated using pressure from the power steering system.
The key here seems to be that the power steering isn't functioning. This tells me that either there is a blockage in the rack or the oil cooler, or the fluid level is low.

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Monday, July 4th, 2011 AT 4:34 PM

SHANNEY1

MEMBER
3 POSTS

THE FAN IS RUNNING WHEN THE ENGINE IS ON, IM NOT SURE IF IT IS GOING AT ITS FULL SPEED BECASUE IF IM ON THE FREEWAY GOING AT LEAST 80 THE CAR STAYS COOL BUT IF I'M IN TRAFFIC OR AT STOP LIGHT FOR TOO LONG THE TEMPERATURE STARTS TO RISE. SO IF I HOT WIRE THE FAN AT THE BATTERY THIS SHOULD HELP KEEP THE CAR COOL UNTIL I CAN GET THE POWER STEERING WORKING CORRECTLY

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Monday, July 4th, 2011 AT 5:05 PM

RIVERMIKERAT

MECHANIC
6,110 POSTS

If the radiator isn't the proper size for the engine and accessories, that can cause overheating when sitting in traffic.

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Tuesday, July 5th, 2011 AT 1:21 AM

ASEMASTER6371

MECHANIC
52,797 POSTS

First of all, no thermostat is the a problem. You cannot runs todays motors without a thermostat. I would start ther and move forward. I hope there is no internal damage from this. I suggest a leak down test to verify no head gasket damage.
The rest of the responses are good about the fan control. If it was bad, it would heat up at a stop but would be normal when moving.

Roy

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Friday, July 8th, 2011 AT 4:47 PM

RIVERMIKERAT

MECHANIC
6,110 POSTS

No t-stat would cause the engine to take an inordinately long time warming up, but, allowing the coolant to flow unimpeded, I am hard pressed to believe could cause the engine to overheat. I t-stat that is stuck closed, I can see, but not a missing one. I'm my 30-plus years of working on cars( 70% of that specializing in cooling systems repair), I've never seen a missing t-stat cause this, except in the rare instance where an external electric, high volume water pump was used.