Why is my KIA Stonic losing coolant frequently – could it be a radiator leak?

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Why is my KIA Stonic losing coolant frequently – could it be a radiator leak?

I own a 2022 KIA Stonic in Lahore, and Ive noticed that the coolant level s every few days even though there’s no visible leakage under the car. The temperature stays normal for now, but I’m worried there might be a small radiator leak o r an internal issue. Is this a known issue in the Stonic, and could it be due to Pakistan’s hot climate o r poor-quality roads?

Talha Kyanii asked on 13 Sep 2025 16:39:46 pm

1 Answer

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Gari Master - on 13 Sep 2025 16:40:39 pm

Yes, frequent coolant loss in your KIA Stonic — even without visible leaks — may be caused by a minor radiator leak, which is not uncommon in Pakistan’s climate. The Stonics cooling system is generally reliable, but it can develop issues due to:

🔍 Possible Reasons:

Hairline Radiator Cracks:
High summer temperatures in cities like Lahore and intense engine heat over time can cause plastic o r aluminum radiator tanks to crack, leading to slow leaks that evaporate before hitting the ground.

Evaporation from Overflow o r Reservoir Cap:
If the coolant reservoir cap is faulty, hot coolant may escape as steam, especially when idling o r after turning the engine off.

Leaking Radiator Seals o r Connections:
Weak joints o r rubber seals in the radiator o r connecting hoses can allow slow leaks that aren’t obvious during short drives.

Improper Coolant Mix o r Tap Water Usage:
Using tap water o r non-recommended coolant can lead to internal corrosion and pinhole leaks inside the radiator.

✅ What You Should Do:

Check under the radiator and hoses for dry white o r pink residue sign of dried coolant.

Inspect the radiator cap and coolant reservoir for cracks o r signs of steam leakage.

Pressure-test the radiator at a proper workshop to detect hidden o r hairline cracks.

Always use OEM-recommended coolant not plain water o r low-quality coolants.

If a leak is confirmed, avoid using radiator sealants long-term—they’re only a temporary fix and can clog the cooling system.