I have a 96’ Cougar when I got it the top Rad hose had a small leak fixed topped off. Now the temp gauge fluctuates constantly and it wants to heat up quickly at idle. I’ve changed the rad the thermostat and pump with no change but I did change the cap and that seemed to help. Even today at 35* after warmed up sits still for 5 mins creeps up till the fan kicks on then back down and cycle repeats. Any hill makes it move the gauge quite a bit. I also did a block test and it was great so is this norm for the cougars im mainly worried as summer gets here that the problem will be worse. I can’t find any leaks and did used distilled water and Preston to refill.