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Engine heater

Where’s the best place to put a magnetic heater on an engine? The heater is a 2 inch by 2 inch square with a magnet on one face. I wouldn’t like to mount it permanently on the block (it might fall off) . . . so what is the easiest? It’s for a 1995 Civic. I can stick it on the valve cover or exhaust manifold really easy, underneath (the oil pan) would be a bit messy in the snowy-salty NE I live in. Would the exhaust manifold or valve cover do any good? Never used one before. Rocketman

You want the heater near a rezervoir of coolant, this is why they’re recomended on the engine block lower portion ( heat rises ), or a lower radiator hose type heater. When the car is off overnight the coolant settles to the low points and heating an upper area of nothing but air space will not accomplish the intended outcome.
Where you think you don’t want to try to put it… is exactly where you need to put it ( re: instructions included within ). Just leave it there forever and plug or not as needed.

Two inch square magnetic heater? How many watts does this thing provide?


You can get a block heater installed, it uses about 100 watts and keeps your engine about 35 degreees I was told on a previous car I had one put in.It replaces a freeze plug, and a blue flexible extension cord in winter is a good item to go with it!(the kind with the light in the end are not the ones to get). I was surprised the last 3 cars we bought actually had one factory installed. 2 bought new from a dealer, I asked the salesman about getting one installed and the salesman recommended having a local mechanic do it. Imagine my surprise when I found there was already there! (2 fords 1 chevy)
After living in grand forks and hearing stories of dipstick heaters frying oil and 400 watt heaters put inline on the radiator hose that did not do much I have little faith in the magnetic heater solution.

The oil pan’s the only spot it’s going to do any good. Your car has too much coolant and it’s spread out too much for a dinky little stick on heater to make a difference, but having it on the pan might make the oil circulate just a tiny bit better on start up. Not that there’s an epidemic of Honda engines prematurely failing in the cold country.

If you’re looking for instant or faster heat, you need one of the block heaters that installs in line and circulates the coolant or a freeze plug style one. The magnetic kind are okay for situations in which you need a block heater just to stop the anti-freeze from freezing overnight, but they really don’t crank out enough heat to actually make the coolant anything you’d call warm.

Sorry . . it’s 2 x 4 . . . it says 200 watts, made by “Zero-Start”, in Canada. I had it given to me, brand new, never used . . . but no instructions. Maybe I will attach it to the lower block . . . just being lazy I guess. It’s not all that cold, and the wife’s civic starts fine . . . just thought I could warm it up faster for her in the really cold weather. Rocketman

Thanks guys! I’ll let you know how things turn out. Rocketman

You’re going to be using 200 watts of electricity all night long to make the engine warm up 30 seconds quicker? Doesn’t sound like a good deal to me. I question how much heat the magnet will transfer to the block. Putting a light bulb under the hood would probably work just as well, which is to say, not very.

I suggest sticking it on the bottom of the oil pan. It’s the only place you have any hope of getting any heat, and if you’re lucky the thing will fall off and you won’t have to worry about it any more.

You live near Canada in the Mountains?? Because that’s the ONLY place I know that you’d actually NEED one of these.

When I lived in North Dakota I used a lower radiator hose heater that would directly heat the coolant, which would circulate via convection. It’s a simple coil that is installed directly into the lower heatare hose with two standard hose clamps. It gets way below zero in ND for extended periods.

Those that recommend a block heater or some other type that heats the coolant are correct. Those are definitely the best kind.

Never been to North Dakota or Minnesota Mike?

As stated previously after living in ND where a 46 below was something to be dealt with my thought on the 400 watt heater hose is the radiator will probably be helping cool all that you heat before it has a chance to help your engine, I had one once and ditched it when I lived in Illinois for the block heater.

I see your point, but it worked great. Of course I neglected to add that we had blankets or corregated cardboard in front of the radiators anyway. Without that the engines could not warm up at all when he car got moving and the air started passing through the radiators.

Remember that the heated coolant migrates via convection upward through not only the radiator but the engine too. Without the waterpump running and with no air passing through the radiator or past the engine, the warmed coolant simply goes up via any and all pathways, the cooler fluid dropping down past it within the same cavities…or via whatever natural path develops. Fluid direction is completely uncontrolled when the engine is off.

Block heaters were, I agree, better than the hose heaters.

Those little heaters are for the oil pan. It just keeps the oil warm not the coolant. Putting it on the block will do no good at all. You really should remove it though before driving since they are known to fall off.