Hello all, I’ll start from the beginning. Corsa A GSI C20XE. Drive the Corsa from 4 – 10 , end of the year then oil at the surface of the cooling water… Winter break… – Was a KS 700 he head , worried by a known head , an 859 he. – Cooling circuit washed – head changed , outlet NW taken over because of 2.5 mot. – Short test drives last month when it was dry. Everything without problems. Well. Today afternoon times on the slopes and it didn’t take long… – At the acceleration nigen was as if i was slowing down and at about 5000 revolutions a clear thrust came again. – Then I hung up and wanted to treat the candle plugs with el. spray —- it was as if there was vacuum in the lid while trying to pull off the first plug!!!—- ( I never noticed before ) – Then again test drive and it went through clean. At the same time the temperature indicator no longer went and the DZM shows almost nothing. Verbaut is a DIGI Tacho. If ever I have two hours to look for.. THANK YOU