Just three days before Chinese New Year on 9th February 2021, my VW Polo unfortunately broke down. It was a regular morning — I had just dropped my son off at kindergarten and was heading back home to start my WFH routine (yes, still working remotely due to the pandemic). Just as I arrived at my parking lot, I noticed the air-conditioning wasn’t cold, and then the high temperature warning light started flashing.
I immediately turned off the engine to prevent any potential damage. After waiting about an hour for the engine and radiator to cool down, I cautiously inspected the radiator expansion tank and took a closer look around the engine bay.
While the radiator fan was functioning correctly — including both speed settings — I discovered signs of coolant leakage just beneath the thermostat housing. The pink coolant trail led down onto the top of the gearbox, clearly visible in the engine bay. This pointed to a likely thermostat failure, which could have disrupted the coolant flow between the radiator and the engine.
After allowing the engine to cool further (over two hours), I managed to drive it slowly to my mechanic. Upon inspection, we found two potential culprits:
- A failed thermostat, the main suspect due to the visible leak.
- A heater pipe, which also showed signs of deterioration — although it’s a bit questionable why we even need a heater pipe in Malaysia’s climate.
Both parts were replaced promptly with genuine VW components. Fortunately, after the replacements, the Polo has been running smoothly with no signs of overheating since.
For anyone experiencing similar symptoms — no cold air from the A/C, temperature warning lights, or coolant leaks — make sure to inspect these areas. Left unchecked, overheating can lead to serious engine damage such as a blown head gasket, warped cylinder head, or even a cracked engine block.
Below are the part numbers and prices for reference. I haven’t included labor costs as those can vary by workshop.
