Coolant overflow and no heat

[Channel Hopper]

So, I did another run today (146 mile round trip, mostly motorway stuff), the gauge never went two stops before midway.

I have recently replaced the coolant reservoir overflow cap with a £7 equivalent from the local dealer - 9psi relaease but can't confirm if this has fixed things since the outside temperature
has dropped in the past few days.

Returning home, nothing has been lost from the system.

I have a similar run next week, with perhaps a few stops and will check levels again.

 

[A J Clarke]

Wow u went through some amount of investigation to find out what is going on. Im replacing oil cooler and new oil cooler gaskets in a few days. Oil i coolant but car still runs great. Temperature is under halfway. Flushed coolant system 3 times. I'll keep flushing every second day until the gasket set arrives in honda in 6 da6s. Fingers crossed i dont have a cracked head like yours. Head issues are a very very very rare issue with these i-DTEC 2.2 diesel engine. Cheer Arron