How long does an engine coolant heater need to be plugged in?

[5030]

I had one of the engine heaters that gets cut into the radiator hose. I would plug it in and hour or two before I wanted to start the tractor and it didn't seem to help at all. Did I need to leave it plugged in longer? Like over night? Was it a junk heater? Do they not really work below O degrees? Should I have had a battery heater?

Depends on a number of factors. heating time is dependent on the wattage of the heater element, where it's located in the cooling system, the outside (ambient temperature and if the unit is sitting out in the cold wind.

The best heaters install in the block in a freeze plug hole and have direct contact with the coolant itself within the block. The least efficient ones are low wattage units that install in the lower rad hose and the terrible ones are the ones that magnetically attach to the oil pan.

 

[pmsmechanic]

A few have mentioned electricity costs. I phoned my power company a few years ago and this is the formula they gave me.

Watts divided by 1000 = kilowatt hours (kwh)
Kwh x electricity cost = cost/hour

So in my case:
Oil pan heater is 250 watts. 250/1000 = .25
My electricity cost is $.10945/kwh CAD.

.25 x .10945 = $.0276625/hour CAD or about 2.8 cents/hour. So I don't get too excited about leaving my diesel Jetta plugged in for an extra hour or so.

Lets figure for a different scenario.

1000 watt heater/1000 = 1
Electricity cost is $.15 USD.
1 x .15 = $.15/hour USD electricity cost. Even that is pretty reasonable to have your tractor or vehicle start easy.

My conclusion is that a block or oil pan heater is not a place to be frugal. That being said I don't like to leave them plugged in all night either. They seem to burn out quicker then.

Someone wanted to know about oil pan heaters. The stick on ones work great on my older Jettas. The biggest issue is gravel roads scraping then off if you don't have an engine shield. I don't like paying NAPA $120/heater so I order off the internet for about $25/ 250 watt heater. I always have a few in stock.

I also have some magnetic heaters. They work great to warm up the oil if your in a hurry to get the motor started.

 

[Agvg]

Someone wanted to know about oil pan heaters. The stick on ones work great on my older Jettas. The biggest issue is gravel roads scraping then off if you don't have an engine shield. I don't like paying NAPA $120/heater so I order off the internet for about $25/ 250 watt heater. I always have a few in stock.

I also have some magnetic heaters. They work great to warm up the oil if your in a hurry to get the motor started.

How cold is it in your area?

 

[pmsmechanic]

How cold is it in your area?

In winter overnight temperatures can see -20 to -30 C on average. We can get colder. -40 C is not impossible but not common either.

Unless we get a chinook. Then all bets are off. I've seen a weather change from -30 C to 10 C over 8 hours or so. I've also seen 2 feet of snow disappear off of the fields over night. It's not a regular occurrence but happens several times a winter.