I just installed a 600W block heater to my 5.4 V8 the other weekend. It got down to 15 degrees this morning so I plugged it in last night on a timer to start 3 hours before I leave for work. I checked to hear if it was on before I left as I'm told you can hear the element buzzing. I also felt around the element area (not the actual element piece itself) and it was warm to the touch. I start my truck up and temp needle doesn't move. Ok I thought, maybe it heat the coolant up but not enough to register on the temp gauge. Turn heaters on, still cold air. It still took a majority of my 6 mile (15 min) commute this morning for the engine to warm up to operating temp. I didn't really notice any decrease in warm up time. Are my expectations too high? Am I doing something wrong? Is 3 hours not enough time to warm it up? Any insight is appreciated.

 

I dont have a block heater, since I'm in the south, but I would think that the reason they are there is to heat the block itself...not the coolant or oil. This is to prevent block cracking when the block goes from extreme cold to hot when the engine runs. Maybe I'm wrong, but I don't think that there is an issue here...

 

Also, keep in mind that the stock coolant meter is a dummy meter. It shouldn't be used to get accurate readings. All it does is register when the coolant is up to operating temp and when it begins to boil over. Try an actual scanner and see what the true temps are.

 

When you said a block heater, I'm thinking of the magnetic heaters stuck on the oil pan or the side of the block. I think the 600W block heater is too small for what it seems you are looking for. For example I have a 1500w Kats coolant heater on my diesel tractor, within 2 hours the temp will rise and I can start it without the glow plugs. Coldest has been 5 degrees.j Maybe an overkill, but I didn't want to wait half a day just to start it in cold weather.. Could have easily used a 750W.

The coolant heater I think works better that a block heater just my 2 cents
This is what I have on the tractor connected on what would be the heater hose.
https://katsblockheater.com/block-heaters/all/circulating-coolant-heater-1500-watt-120-volt

Just an example for your truck, not sure of the year or size. Freeze plug heater
https://www.jegs.com/i/JEGS/555/51120/10002/-1

They also have heater that are inline with the lower radiator hose. I didn't want to cut the hose for those..

Aubrey

 

Before you start it next time see if it's still warm to the touch. If so, I'd say that's about as good as that one is going to get.

 

Thanks for the responses everyone. I thought I was thorough with my research but it sounds like 600W might not be enough. This is a chart from this morning. Outside temp was probably closer to 25 degrees not 40 as the chart suggests. That number adjusted to the correct outside temp when the vehicle started moving. After about a minute the coolant temp was 70 degrees. I'm guessing that is a combination of the water pump circulating the coolant towards the coolant sensor and the engine warming up. Either way, I'm not sure what to expect when the temps get to 10 below which they do tend to in the winter. I guess we will see. Maybe I'll need to swap out to the 1500W system mentioned above.