Engine Block Oil Stick Heater
 

Will an oil stick heater keep the water from freezing that is still in the system? I have seen oil stick heaters made for cars, so they will turn over easier in colder weather up North. Here in Tennessee the weather stays warmer until end of December. But, some nights get into lower 20's and days back up to upper 60's. I want to use the boat longer. Just worry about the outdrive. Boat is out of water on the trailer kept outside. Some boaters up North leave a 75 watt light bulb on in engine compartment to keep engines from freezing.

I've never heard of an oil stick heater, but the idea sounds interesting. Does it heat the entire engine? It seems like it'd only heat the oil. I don't know if I'd rely on it for keeping the whole engine warm during those nights of 20 degrees. The 75W light bulb is a commonly used trick, but remember you're introducing electricity (110v) into an area with gas vapors. If by some chance the bulb were to break and ignite a spark, your boat would catch fire. There's been a few incidents of this that I've heard of. It's scared me a bit from trying this. You could always pull the freeze plugs out of the engine block and drain the water out, just make sure and put them back in when you're done or you'll have a big problem next time you fire up the engine.

Or, if you've got a higher budget, they actually make specialized marine engine heaters that slide underneath your block and create enough heat to keep everything warm.

Or, the other option is take the boat out and run it for at least a half hour on those days when it's going to get cold. Heating the block up about 175 should keep everything above freezing for a day or so!

At any rate, if you feel threatened by the cold weather, and temps stay down below 32 for more than a day, it might be best to get the engine winterized. Have you seen the cost of a replacement engine? Better safe than sorry!

Hope this helps.

Back in my schooling days I had a car that was tough to start in the winter. Someone game me one of those dip stick heaters to try and it didn't seem to make a bit of difference. I then tried one of those magnetic oil pan heaters and it worked a ton better at heating the oil. I don't know that I'd trust either one to keep your block from freezing, but I know the dip stick version did not produce nearly as much heat as the magnetic one.

If it were me, I think I'd go with the light bulb in the engine compartment trick. The engine compartment is completely closed in and you'd be surprised at the amount of heat a light bulb gives off.

Edit:
As a foot note: Don't touch either heater to test their temperature. The magnetic one that I had would get hot enough that in the dead of winter, it could sizzle spit.

I know a lot of guys that simply drain the block for winter (besides fogging and fuel stabilizer). Just make sure you get all the drain plugs out!

I wouldn't try any sort of heater/light not approved for marine bilges. It's not worth the risk. Draining the block is extremely easy, then just lower the outdrive so it doesn't retain water either.

Re: Engine Block Oil Stick Heater
 

I know this question was asked a long time ago but I just joined :). Don't use the dipstick heaters. This is something I know about because I live in a town that can get 40 below zero. People try to use these all the time to keep their cars warm. The dipstick heaters don't seem to be consistent in watts that they are rated for (because they are cheap) and many times they burn the oil. I have used Kats magnetic heaters before and they seem to work pretty well.