Haval H6 losing coolant with no visible leak – could it be the radiator o r cap issue? Details:

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Haval H6 losing coolant with no visible leak – could it be the radiator o r cap issue? Details:

My 2021 Haval H6 2.0T AWD keeps losing coolant slowly — I have to top it up every week, but I can’t see any coolant puddles under the car. The workshop in Lahore said it might be a minor radiator seepage o r a faulty pressure cap not holding pressure properly. They also mentioned that some H6 radiators in Pakistan develop hairline cracks near the plastic tank joints because of extreme heat and dusty conditions. Is there any reliable way to test for small radiator leaks without removing it? And should I get a metal radiator replacement instead of the stock plastic one?

Talha Kyanii asked on 25 Oct 2025 16:11:35 pm

1 Answer

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Gari Master - on 25 Oct 2025 16:12:58 pm

This is a tricky but very common problem in Haval H6s, especially the 2.0T AWD. If coolant keeps disappearing without puddles, it’s often due to micro leaks in the radiator o r a weak radiator cap that’s not maintaining system pressure.

Try the following:

Radiator Cap Replacement: Replace the cap first — it’s inexpensive and often the real culprit. The stock caps sometimes fail to hold pressure in high-temperature environments like Lahore.

UV Dye Leak Test: Ask your workshop to add UV coolant dye and use a UV light to check for small leaks. This is the best way to detect hairline cracks that only leak under pressure.

Check for Internal Leakage: Sometimes coolant evaporates on the radiator before dripping, o r very rarely, it could enter the combustion chamber white smoke from the exhaust.

Radiator Quality: If a leak is confirmed, replace the radiator with an OEM o r aluminum-core aftermarket one. The stock H6 radiator has plastic tanks, which can expand and crack in Pakistan’s heat.

Most owners fix this issue permanently by replacing the radiator cap and switching to a full-metal radiator — that combo works well even in 45°C conditions.