I have noticed this lately. I normaly run between 185 and 190 during operation, but after I park and shut the engine off, the temperature will slowly rise sometimes as high as 225 before it begins to fall. Is this normal? The car never overheats and the coolant light never comes on.

PLease comment

 

i can't speak on actual numbers, but it would seem "normal" that temperature would rise a bit after circulation stops.

 

Totally normal. The gauge measures the temperature of the coolant, not the engine. The engine runs hotter than the coolant, up to 200 degrees hotter in places, so when you shut the engine off, the coolant trapped in the engine absorbs this heat as everything equalizes.

Might be a good idea to run some Water Wetter to be safe. If you have film boiling around the spark plugs, the engine can be overheating and you'd never know it because the coolant is staying cool. There's also the NPG route, which won't boil in the first place.

 

Kindly explain film boiling

 

It's just as the name implies - there will be a thin layer of steam around a hot spot on the engine. The steam insulates the coolant from the metal, so the metal gets very hot since it can only lose heat by transferring it to cooler parts of the engine rather than liquid coolant, and this extra heat perpetuates the steam generation, making it that much more difficult for coolant to get to the metal. It's not a good thing, but it does happen.

 

a relay to keep the fans active with the car off also helps.