* Thermostat stuck open: This is a likely culprit. A malfunctioning thermostat that remains open prevents the engine from reaching its optimal operating temperature. The ticking could be unrelated, or it could be a component affected by the low temperature (e.g., a valve tappet ticking louder due to insufficient lubrication from cold oil).
* Coolant leak: A leak in the cooling system could cause low coolant levels and subsequently a low engine temperature. The ticking noise might be unrelated, or it could stem from a component damaged by overheating (though this seems less likely given the low temp).
* Faulty coolant temperature sensor: An inaccurate sensor could be reporting a falsely low temperature. The ticking would then be a separate issue.
* Water pump issues (less likely with low temp): While a failing water pump typically leads to overheating, a very early stage failure *might* lead to insufficient circulation and low temperature. A ticking could be related to bearing wear.
* Timing chain/belt issue (possible, but less likely related to low temperature): A noisy timing chain or belt can cause a ticking, but this wouldn't usually be directly related to a low engine temperature. However, if the ticking is metallic it warrants urgent attention.
* Valve train issue (e.g., lifter tick): Low oil temperature from the low coolant temperature can exacerbate valve train noise. This is more likely if the ticking changes with engine temperature.
What to do:
1. Do NOT continue driving: Driving with a low engine temperature can cause damage, especially if the problem is a lack of lubrication due to cold oil.
2. Check the coolant level: Open the coolant reservoir (carefully, as it might be pressurized) and check the level. Look for any leaks around the radiator, hoses, or engine.
3. Listen carefully to the ticking: Try to pinpoint the location as accurately as possible. Is it a constant tick, or does it change with engine speed? Is it a metallic sound? This information is helpful for a mechanic.
You need to take your vehicle to a qualified mechanic for proper diagnosis and repair. Driving with these symptoms could lead to significant and costly engine damage.
