Hello, I'm new to the board. Car enthusiasts but use my trusty lexus as a daily.

On to the problem. Car started over heating. I noticed the resorvior next to the radiator was low. I filled to max level. Car will over heat on the highway. No issues driving in the city. Car will not over heat sitting at idle with ac on. Radiator fans never kick on. Ac turned on and fan will not kick on. It is 40F out so that is helping things.

Car has 114k miles. Possible the water pump is on the ropes but I would like to Address the fan issue first. Fuse look okay.. are the fabs known to die? Fan ecu?

 

It sounds like the fan is not running. Could it be that the thermostat is not working?

It could also be the water pump. There are several possible causes.

 

There appear to be multiple issues.

Low coolant in reservoir. How often do you have to top off? Once a year or so, and down a little bit, is normal. More often and complete empty reservoir indicates a leak somewhere in the cooling system.

Fans not turning on. Could be a bad radiator temp sensor, loose connection, blown fuse, or blown electric fan motors.

Overheating on highway, but not at low speeds. This usually points to a bad thermostat and/or plugged radiator. Look between condenser and radiator; there could be a bag or debris blocking air flow.

 

I have only refilled the coolant resovoir 2 times in my ownership. Over a year in between the refills. It is holding the coolant as that reservoir has not lost any coolant since. I did not bleed the system of air since It was just one reservoir that was near empty.

The fan Not kicking on is an issue. I beleive the fan does very little at highway speeds so I'm thinking thermostat too.

I'm not seeing any coolant leaking around the water pump but there is a lot in the line of view too.

 

**Update. Signs of pink coolant around the back of the water pump. So I ordered a new WP, belt + outer thermostat.

Job doesn't look too bad. Actually looks easier than the Gen2 IS I previously owned and performed the same job.. what blows is that its winter time.. mehh

Thanks for the responses. Fan issue to be continued after this WP.

 

With the belt off, check your pulley/bearings for play and drag. I usually replace the idler and tensioner pulley bearings at 150K as preventive maintenance no matter what, along with belt, thermostat, and hoses, and the 150K coolant flush.

 

2nd on the water pump. They’re weak.