help tu 1.4

[Nexus]

It is not good to jump to conclusions - Start with the simple things first and work your way up in severity.

If I was having this problem myself I would be checking:

• Bleeding procedure
  
• Condition of spark plugs in each chamber
  
• White smoke while engine is warm/hot
  
• Endoscope (camera) down in to the combustion chambers
  
• Perform a coolant system pressure test (a garage can also do this for you)
  

All of the above are checks to check HG. The big question is are you actually losing coolant? Coolant will either be lost with a pipe or rad leak, or through the head gasket. If you are NOT losing any coolant, then surely it can only be an airlock causing the issue. If you mentioned that the system works fine when the thermostat is removed, but overheats when the thermostat is IN, then it is an airlock which will be down the how the system is being bled to begin with.

Without seeing the vehicle and how it behaves in person it is difficult to pinpoint anything absolute. What I have learnt is not to overthink things and to start with small obvious things which may have been overlooked. Small details can cause havoc if not followed correctly.

Hope this helps