I own a 98 civic ex with a b18b1 swap. when im not driving for example sitting at a red light my coolant temperature starts to rise pretty quickly but when im driving it drops to normal level. any ideas why?

 

Is your fan coming on? If not, change your fan switch.

 

i actually dont know i didnt check but wouldnt it heat up worse when driving around then just sitting there if the fan wasnt on??

 

When your driving around there is natural air passing by the entire block which cools it, sitting still is like you sitting in a sona your not working as hard as running around outside but the think hot air beats the crap out of your engine