Overheating

2003 HONDA CIVIC HYBRID

248,861 MILES • 4 CYL • AUTOMATIC

JEANAMCKEE

MEMBER
2 POSTS

I changed the thermostat, the radiator cap and flushed the radiator . i don't hear fans come on. my heat comes out cool when it comes on. Sometimes it does not blow out.

Apr 24, 2020 at 9:59 PM

ASEMASTER6371

✓Experienced Mechanic
52,796 POSTS

Good morning,

From your description, it sounds like the heater core may be clogged with debris. I would remove the heater hoses and use a garden hose to flush it of all debris. I would do it several times back and forth until you get a good even flow.

https://www.2carpros.com/articles/car-heater-not-working

https://www.2carpros.com/articles/replace-heater-core

If that does not take care of it, the heater core will have to be replaced.

As far as the overheating itself, I attached a wiring diagram for the fans. Without the fans working especially at idle, the car will overheat as there will not be enough air flow through the radiator.

https://www.2carpros.com/articles/engine-overheating-or-running-hot

https://www.2carpros.com/articles/how-an-electric-cooling-fan-works

Do you have a voltmeter or test light to do some checks?

https://www.2carpros.com/articles/how-to-check-wiring

Roy

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Apr 24, 2020 at 10:14 PM

Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.