Question about 1991 Mitsubishi Montero

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I have (or my kid has) an old 91 firefly with a

i have (or my kid has) an old 91 firefly with a blocked heater core There is some heat but not very much..---- Can I flush this out myself with water pressure or should I seek more expensive methods such as a rad shop?

note that I replaced the thermostat eliminating the chance of it being stuck wide open. Also I plugged a hole in the rad using alumaseal---perhaps this was the downfall of the heatercore, although Ive never had problems before with this type of product before.
Love to find a cheap fix for this old car.

Best of the season to you and your family.

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Yes drain the coolant and then add 200grms of caustic soda and run engine till hot then give a good flush and then remove the heater feed pipes and flush with hose reversing direction a couple of times ,might help but cant guarentee it because the layout of the heater coil is such that the water doesnt pass from one side to the other but the inlet and outlet are both on teh same header tank .But the caustic will help to more some of the clag

Posted on Dec 12, 2009

Testimonial: "The water flush sounds good- I wonder if i might run into problems if i put the caustic soda into my rad since i have used a pour infix for a rad leak"


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