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Cooling system and radiator repair at Sager & Sons Auto in Boise, ID
Cooling & Heating Systems in Boise, ID
Don't Let It
Overheat.
Idaho summers are hard on cooling systems. A slow coolant leak, a failing thermostat, or a worn water pump can take a routine drive and turn it into a very expensive repair. We diagnose and repair the full cooling and heating system so your engine stays in its safe operating range year-round.
Full System Diagnosis
Pressure Testing
3-Year / 36,000-Mile Warranty
Schedule Your Drop-Off

Cooling & Heating System Repair in Boise, ID

Diagnosis first, we find what's causing it before recommending repairs

Your engine has a narrow safe operating temperature range. Too cold, and it wears faster and runs inefficiently. Too hot, and you're looking at head gasket damage, warped components, or a seized engine. Your cooling system keeps it in that range, and when something goes wrong, it usually escalates fast.

Overheating is an emergency, pull over immediately.

If your temperature gauge spikes or you see steam from under the hood, turn off the engine and call us. Driving through an overheating event can cause engine damage that costs thousands to repair.

Cooling & Heating Services We Provide

From the radiator to the heater core, the full system

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Thermostat Replacement

A stuck-open thermostat causes slow warm-up and poor heat. Stuck-closed leads to overheating. We test before replacing so we fix the right component.

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Coolant Flush & Fill

Old coolant loses its corrosion inhibitors and can damage aluminum components. We flush, refill, and pressure-test to factory spec.

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Water Pump Replacement

A failing water pump can leak, make noise, or stop circulating coolant entirely. We inspect belt-driven and electric water pumps and replace when necessary.

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Radiator Service & Replacement

Clogged or leaking radiators can't dissipate heat properly. We inspect, test, and replace radiators when flushing doesn't restore proper flow.

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Hose & Belt Inspection

Coolant hoses and the serpentine belt driving the water pump are common failure points. We inspect for cracking, softness, and wear on every visit.

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Heater Core Diagnosis

No heat in the cabin, fogging windows, or a sweet smell inside? We diagnose heater core issues and provide clear repair options before any disassembly starts.

Warning Signs of a Cooling or Heating Problem

Catch it early, a small leak is far cheaper than an overheated engine

Temperature gauge running hotter than normal
Low coolant warning light
Sweet smell under the hood or inside the cabin
Coolant puddles where you park
Heater blowing cold air
Foggy or film-covered windshield from the inside
Engine slow to warm up in cold weather
Steam or smoke from under the hood

Cooling & Heating FAQs

Straight answers about cooling system repairs

Can I add water instead of coolant in an emergency?
Plain water can be used in an emergency to get you to a shop, but it should be replaced with the correct coolant as soon as possible. Water doesn't have the corrosion inhibitors or freeze protection that coolant provides, and can cause damage over time.
How often should I flush my coolant?
Every 2–5 years depending on your vehicle and coolant type. Some newer vehicles use extended-life coolant rated for 150,000 miles, but most older vehicles need service sooner. We check yours every visit.
Why is my heater blowing cold air?
The most common causes are low coolant, a stuck-open thermostat, a blocked heater core, or a blend door issue. We diagnose before recommending any parts replacement.
What happens if I keep driving with a small coolant leak?
Small leaks get bigger. Running low on coolant can cause overheating, which can warp the head, damage the head gasket, or in extreme cases seize the engine. Don't gamble on it, have it looked at.

Why Boise Drivers Choose Sager & Sons

Pressure Testing
We pressure-test the cooling system to find leaks that aren't visible, including slow internal leaks that don't leave puddles but still cause problems.
Diagnosis Before Parts
We test thermostats, water pumps, and hoses before replacing them. You don't pay for parts you don't need.
Complimentary Digital Inspections
Photos and notes sent to your phone, so you see exactly what we found and understand the repair before approving anything.
3-Year / 36,000-Mile Warranty
Every qualifying repair backed by our NAPA AutoCare nationwide warranty, honored at 14,000+ locations across the U.S.
Family-Owned & Operated
Serving the Boise Bench since 2012. We're not a chain, and we treat your vehicle accordingly.

Temp Gauge Running Hot?

Don't wait, cooling system problems escalate fast. We'll diagnose it same-day.

📍 6126 W. Franklin St., Boise, ID  ·  📞 (208) 761-9406  ·  Mon–Fri 8am–5pm
Schedule Your Drop-Off

Oil Change Service

Your engine’s first line of defense. We use premium oil and filters suited to your make, model, and driving habits.

Transmission Fluid Exchange

Keep shifting smooth and prevent transmission failure by replacing worn fluid before it breaks down.

Coolant / Antifreeze Service

Over time, coolant loses its ability to protect your engine from heat and corrosion. We’ll flush and refill it to restore balance.

Brake Fluid Flush

Moisture contaminated brake fluid can cause corrosion and reduced stopping power. We replace it for safe, responsive braking.

Power Steering Fluid Service

Fresh steering fluid keeps your steering smooth and quiet, preventing premature pump or rack wear.

Differential & Transfer Case Service

Critical for trucks and AWD vehicles clean gear oil protects bearings and gears under heavy loads.

Sager & Sons Auto in Boise, Idaho

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