Thanks message.
Im not sure if the car running normally (for long distances, 100s miles sometimes) after "I clear the fault/blockage by revving" .... means it is not head gasket / major engine issue.
** I'm not sure whether revving is "clearing" anything. Just assuming.
I've done several 1000...
Peugeot 207 1.6 hdi, 2010 105000 miles
Never been able to show this fault happening to a mechanic, because intermittent. AA have run a diagnostic (dont know how thorough - spent about 15 mins doing it) Bought for 1200 at garage.. probably worth 700 in working condition? Any advice much...