Possible Headlift on Standard PD130? Help!

Hardcore

Diesel lover
Jul 31, 2013
130
0
West Scotland
Standard mapped & turbo PD130
Turbo back exhaust.
122k miles
FSH
Full coolant change done approx 2 years ago. Header tank swapped at same time also (so nice and clean)

Approx 2 weeks ago noticed i was starting to lose coolant.
Can hear hissing from around header tank area and noticed the header tank is really wet.
Replaced cap with one from my other PD130. Still hissing and still losing coolant.

Get a slight bit of pressure when removing the cap, even if the engine is cold.

If i'm lucky the coolant bottle might have a crack somewhere. Pipes look fine so ordered replacement bottle to check.

I've read a few stories of standard PD130, 115 etc getting headlift from stretched bolts on the higher miles.

What else can i do to check for headlift?
Has anyone ever sorted it by tightening the bolts a bit more on the head?
 
Progressive Parts, performance parts and tuning specialists