When i drive my mrk7 escort 1.8si in first and second the revs are fine, then i get into third gear and go over (2000rpm) and put the clutch in the revs go up to (3000rpm) by itself and stay ther for around 30 to 40 seconds, could anyone please tell what the problem(s) could be???? and if an engine service could solve the problem bit pricey tho!!

you could try cleaning the idle speed controlle valve and see if this improves the situation.

My Son's 1.6 Zetec did this, replaced the EMS temp sender and problem has gone away

Does the problem happen when the car is cold or hot.