When starting my car the thermostat slowly rises to the top (just before the 3line), whiles still blowing cold air out of the vents in till I’m just about to stop it quickly drops back to normal running tmep and starts blowing out hot air! HElp!

Also my car seems to run rough when driving the cars not smooth it's kind of like stuttering..
Example if you leave it in 1st runner all on idle it's jumps (kangaroo style) not really bad but I can leave it doing it cus it annoying!

Please help me obi one you’re my only ........ Sorry any ideas?

 

Anyone?
could it be the thermostat?

 

could be the coolant temp sensor playing up. That can cause poor running as it may tell the ecu the engine is hot when it is cold so not putting as much fuel in and vice versa