How long should I wait before attempting to install my EBH if the car is already "warm and toasty"? The outside temp should be in the 50's once the car is off, if that helps... Side note - wasn't sure if I should post in this or the modding forum. Mods, feel free to move this post.
When Wayne(FireEngineer) came to install mine, he said ~45 minutes to an hour since the EBH is installed very close to the exhaust manifold.
Engine Block Heater There are 2 kinds, the older immersion style that usually fit into a frost plug and directly heat the coolant. The one for the Prius, my FJ, and most other Toyota fit into a cavity in the block, which heats the block and - indirectly - the coolant
you won't damage the EBH if you install it while the engine block is hot, but to save your self some pain (unless your into that) wait however long it takes to touch the engine with out it burning you.
