glow plug based coolant heater

[Coyote X]

Some glow plugs draw 15 amps so depending on the plug it can put out 150-250W of heat. So how about mounting 3-5 of them in the intake line going to the heater core. It would load the engine down by making the alternator work harder. That also helps warm the engine up faster. If there were 5 of them running it would be ~1000W of heat being put into the coolant along with the extra load from the alternator.

On most cars the heater core is on a bypass so it circulates no matter what the thermostat is doing. It would also put a bit of heat into the heater box to give a bit of heat to help keep the windshield clear.

I figure my car takes about 5 minutes of driving to reach operating temperature. I don't know how much faster it would warm up with a setup like that though. Anyone got any ideas?

[Frank Lee]

Intriguing idea!

Only thing I'm wondering is, glowplug tip temps get very hot- how hot I don't know- would they fry the coolant and/or would there be enough flow to prevent that?

[SVOboy]

This is indeed an interesting idea. How much money do you think this would cost to set up?

[Coyote X]

I have seen 8 packs of plugs for 50 bucks on ebay. It is really hard to find specs on them though. I have not been able to find a listing of current or wattage anywhere.

They heat up to 900 degrees but with water moving even slowly it would not boil the coolant since they would only be on when the engine was under 80-120 degrees F or so.

[Coyote X]

I keep seeing 12A for fast glow plugs on pages so I think that seems like a pretty good bet to stick with.

so 12A X 14V = 168W each. 1300W for 8 of them. That seems like a decent amount of heat to me.

So anyone here using a block heater that pulls like 500W or more? How long does it take to warm up the engine by itself?

[SVOboy]

I think darin's block heater pulls > 500W

[dremd]

Just get the coolant glow plugs from a TDI. There are 3 of them, supposedly they add up to 750watts. They last the life of the car (mostly), factory turn off is 110degF coolant temp. I want to have my ecu modded to run till 125 ish . . .

[MetroMPG]

Originally Posted by Coyote X

So anyone here using a block heater that pulls like 500W or more? How long does it take to warm up the engine by itself?

I haven't measured the time vs. temp of my 800w inline tank style unit.

The external 300w bolt-on heater that I installed first: Plugged in for an hour and a half to 2 hours, the engine temperature reads 40-50 F above ambient temperature at start-up, according to the ScanGauge.

Probably not very helpful, since it's not nearly as efficient as an inline heater.

[DifferentPointofView]

Speaking of Block heaters, How long would I have to plug in a 600w block heater to warm my engine up? it's a 6 cylinder. I'm just wondering because I'm gonna buy one, and saw that 750watts takes all night to warm the engine for a six, and like 2-3 hours for a 4 cylinder. It was specs. for a tank type. I'm about to buy a freeze-plug type specified for my vehicle, (not tank type) and the only type is a 600watt one. Also, should I go permanent or removable?

[roflwaffle]

If your warmup time from freezing to say, 92C, is five minutes, and you heat half of your two gallon coolant capacity, then the engine is transferring about 5000W to the coolant, just to put a 1300W heating system into perspective.