Thermostat replacement
The thermostat controls when antifreeze starts flowing through the radiator’s main cooling circuit.
Symptoms
- Stuck closed — the engine overheats; stuck open — it warms up slowly and the heater runs cool.
What's included
- If stuck closed, the engine overheats; if stuck open, warm-up takes longer, cabin heat is weak, fuel consumption rises and wear accelerates. The second condition often goes unnoticed although it is harmful too. We check thermostat operation through scanner temperature data and by feeling the hoses: correct warm-up follows a recognisable pattern. Replacement uses a new gasket, coolant top-up and mandatory removal of air locks, which can cause apparent overheating after repair. Thermostat replacement in Kyiv ends with bleeding air locks to prevent this problem.
Additional checks
- Checking thermostat operation via scanner temperature data
- Checking warm-up by feel on the hoses
Why it matters
The second case is noticed less often, though it's just as harmful: fuel use rises and wear speeds up. Bleeding air pockets after replacement is mandatory, or a false overheating shows up.
More details
The thermostat controls when coolant starts flowing through the large circuit to the radiator. Stuck closed — the engine overheats; stuck open — the engine takes a long time to warm up, the heater blows weak, fuel consumption rises, and wear accelerates. The second case is rarely noticed, even though it's harmful too. We check the thermostat's operation from the temperature data on the scanner and by feel on the hoses: correct warm-up has a characteristic pattern. Replacement is done with a new gasket, topping up the coolant, and mandatory removal of air pockets — they're exactly what causes false overheating readings after a repair. We finish thermostat replacement in Kyiv by removing air pockets — they're exactly what causes false overheating readings after a repair.
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