Debbie Van

driving highway speeds for 30 miles and then within 1 mile after leaving the highway, temperature gauge starts rising. I changed thermostat and coolant sensor. Radiator fans come on when checked. Hose replaced 1 year ago. 1 fan replaced 3 years ago. Water pump and timing chain replaced 1 year ago.now what?

Slumpertcivic

Critical question..... is the radiator full of coolant or does/did it need quart to gallon to fill it back up.

GolNat

iTrader: (7)

I'll leave this here:

https://www.civicforums.com/forums/3...reference.html

Debbie Van

It needed a gallon and it needs approximately 2 cups of coolant added each time I drive it 60 miles

BrotatoChip

Is it leaking coolant? Is the coolant reservoir overflowing? GolNat's link will tell you everything you need.

Slumpertcivic

Now it’s question of do you have a leak in the cooling system or do you have a leak in the head gasket.

At home without shop tools test way to diagnose is to start with a almost empty overflow tank and a full radiator and do your normal daily drive.

After everything is cooled down,
If the overflow is still almost empty and your radiator needs 2 more cups, your likely looking for a coolant leak somewhere.
If the overflow is filled up, likely your head gasket is leaking.