Absolutely no question--
that's a block heater.
Engine heaters as sold for my Luminas. the Temro actually fits, the Kat's isn't even close.
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Sealing O-rings not installed. They'd fit into the groove in the main body.
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First step in removing a block heater is to
find and remove the block-drain plug on that side of the engine. Yeah, it's a pain in the asp, but WAY better than draining the "radiator" and then pulling the engine heater which releases another gallon of coolant on you. Glycol showers are no fun. I generally replace iron/steel block drain plugs (corroded) with brass pipe plugs, or--on vehicles I own--brass draincocks. Then it's easy to drain the block forever afterwards. Your block drain plug is visible in your photo.
You can remove the heater, clean the block hole, and install a proper core plug, sealed with thread-locking compound such as Loctite 242 "Blue". Some folks think a rubber expandable plug is a suitable replacement; until it pops out under system pressure and the engine overheats
with no warning because the dash gauge sensor and the computer temp sensor rely on liquid coolant to transmit heat to the sensor element--and your liquid coolant is all over the roadway.
Around here, I'd test it to see if it worked. If it works OK, and the center screw is tight enough to not cause a leak, pop it out, and look for damage on the rubber O-ring. O-rings are cheap. Lube the O-ring, emery cloth on the block hole to remove rust, sediment, or burrs, and pop it right back in.
If the seal around the center screw is damaged, you may be SOL for repairing the heater. I'd install a new heater in that case--but you don't seem to want/need a heater. The center screw that holds the heater in place does not get tightened excessively. An inch-pound torque wrench is recommended.
Testing heaters to see if they work is fairly easy. Two ohmmeter measurements are "usually" all it takes. Replacement cords are available if the cord is damaged, but the heater is OK.
1. Ohmmeter measurement across the electrical cord blades. "About" 35 ohms is typical.
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2. Ohmmeter testing from either blade--doesn't matter which--to the round ground pin. Meter reading should be "infinite", "Out of Range" "Over Limit" or similar--NO continuity.
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