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Heater Runs Hot At First Then Lukewarm?

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Heater works fine for awhile and then blows lukewarm. also temp gauge is slightly hot. put in a new thermostat and new waterpump.

What kind of Subaru is this? Could be the radiator, over time it will fill with crud and restrict the flow to the rest of the car like the heater core, also making it heat up.

 

Is it still running warm with the new thurmo and water pump?

 

Prwa AAE

Sounds like a clogged heater core to me you can back flush your heater core by reversing your heater lines and running youre engIne than switch it back. When your done you probably want to flush your system to keep it from clogging up again

my EA82 Wagon did the exact same thing. the heater core was clogged. i tryed back flushing it many times. did not work.

 

had to replace the heater core. now it has been working awesome for the last 6 years or so.

 

sorry for the bad news...

 

-=Suberdave=-

replaced my core.....worx great....

 

would do the same:popcorn:

I had luck replacing a faulty radiator cap after flushing heater core. Used a tappered fitting used to repair a garden hose. Fits right in a heater core line.

heater core take 1 hour pull the whole dash out drop cullom and pullout whole heater box as unit watch for cracks were the lines go into core have had good luck with geting a rad shop to recondition cores is fairly cheap

Ya, flushed mine several times, no dice. Really not looking forward to replacing core, but getting tired of freezing.

  • Author

switched the heater hoses and now the heater blows real hot like it should. the temp is still running 190-195 though. may have to get a new radiator.

 

how long should I flush the heater core?

When you see water coming out of the other hose and not coolant. I will do about 2 or 3 minutes per hose.

  • Author
When you see water coming out of the other hose and not coolant. I will do about 2 or 3 minutes per hose.

 

 

thanks. after flushing heater core the heater blows hot now. still runs hot though. i'd like to know where to find a reman radiator or how can i see if it is a blown head gasket. this is a 84 gl.

thanks. after flushing heater core the heater blows hot now. still runs hot though. i'd like to know where to find a reman radiator or how can i see if it is a blown head gasket. this is a 84 gl.

 

Did you do the radiator cap?

  • Author
Did you do the radiator cap?

 

 

yes. new cap. thermostat and waterpump. it takes about 10 minutes to start overheating after getting to 180 degrees. and yes the fan comes on when it is supposed to.

 

this weekend i am gonna switch out radiators with my good daily driver 84 gl. this should tell me something.

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