gerard

hi i am new to this forum . i have a few probles with y grand voyager first one is when you drive the car and keep it at 60 to 80 kms the temputure gauage stays in the middle . but if you get on the motor way and bring it up to 100 to 120 kms the gauge climbs. i was told it could be a therostat so i got one today is there any videos on how to install this part.next problem after driving it till it get hot and then stop it come back to the car it wont start first time i was told it is the fuell fillter houseing so i bought one today with anew wireing lume. any fed back on these problems would be great .