Could be the thermostat stuck closed - not letting coolant get round the whole system and cool efficiently.
Could be head gasket - check for oil in the coolant is the usual giveaway.
Could be water pump failed, meaning water not pumping round the engine.
Hope that helps
Your Peugeot 306 may be overheating due to several reasons, including low coolant levels, a malfunctioning thermostat, or a faulty water pump. Additionally, a blocked radiator or damaged cooling fan can impede proper airflow and cooling. It's important to check for leaks and ensure the cooling system is functioning effectively to prevent engine damage. If the issue persists, consider consulting a mechanic for a thorough inspection.
club.306.com
the diesel tank capacity for a 2001 306 Hdi is approx £80 so around 55litres
Timing on a diesel? your haveing a laugh?
any diesel oil will be fine
TNT
A Peugeot 306 that has a noisy fan and overheating may need a fan replacement. One may also look into the coolant or thermostat to resolve the issue.
put in more coolant but its not running hot
Four
The cooling fan on a Peugeot 306 may kick in upon starting to help regulate the engine temperature, especially if the engine is already warm from previous use. It can also activate if the temperature sensors detect elevated temperatures or if the vehicle's air conditioning system is engaged. Additionally, the fan helps ensure optimal performance and prevents overheating, particularly in warmer conditions or after prolonged idling.
try picking up a new fan relay + check fuse and module fan behind bumper
I have a problem with my Peugeot 306 deasel pump its not idling