Hi, my octavia 1.6 tdi 5 speed manual 2013 has recently got 2 faults, I think they are related. When I start the car in the mornings the revs jump to 1800 rpm for a sec and then idles at 1100 for a min, then comes down to normal (750ish). It only does that the first time I start the car in the day. I do a lot of miles a day and realised my coolant temperature stays at 50 degrees even if I've driven all day. It sometimes goes upto 65 degrees for maybe a 30 secs and then goes down back to 50