Okay guys, as some of you may know I just replaced the block heater in my 7.3 two weeks ago. I tested it before I installed it and I tested it after I installed it and burnt myself touching it to see if it was warm, it was so hot. I plugged the truck in to a timer two nights ago so it would come on about 3am. I went out to leave around 6:30 and the coolant and engine didn't even appear warm. I got home last night after work and immediately plugged the truck in and it was in all night until about 6:30 again this morning. I checked both top and bottom rad. hoses, valve covers, and eventually crawled under it in the mud to feel the heater and block around it... I couldn't feel any warmth which would lead me to believe it probably isn't working right? All opinions are valued.

 

Did you replace the cord also? Are you sure your extension cord is good?

 

if everything was cold, it sounds so.
did you check the power wire?
on mine the plug end was bad.

 

I just attempted to install a new one last weekend. Havent tested it with power yet because it blew coolant out around the o ring the first time I drove it. Hoping I can get it to seal by tightening the screw and not needing to drain all the coolant AGAIN. there were 2 things I read while researching the job

1. when installing, rotate back and forth till you feel the element contact the inside of the block on both sides. Center the element so that it doesn't contact on either side. the heater will short if contacting block.

2.Do not heat the element untill the block is filled with coolant and engine has run for about 20 min to bleed out air pockets.

Obviously as stated above you should first test the cord for continuity. Should be at or near zero ohms. The heater I bought came with a new cord.

 

Yep, the cord is the brand new one that came with the heater. I've been driving it for two weeks and this is the fist time I've used the block heater. I guess I have a few questions...

1) If the heater element was touching the block and shorting out, wouldn't it trip the breaker?
2) what do the air pockets do to the heater element?
3) if the resistance was in my extension cord instead, could that cause issues?
Cause I've run a 200 watt pad heater off of it and a 100 watt light bulb, but 1000 watts for the block heater is a big step up. I'll check the plug for resistance and then try a new extension cord just to see I guess.

 

1) Probably would trip the breaker, although when you think about it, the coolant will conduct electricity too, so the block heater has to have an insulated covering over it or it would always be shorting out...?

2) The coolant keeps the block heater from over heating. If you turn it on in the air, you can quickly burn the element out. The same thing goes for electric water heaters in houses, if they aren't full when you turn them on, you can fry the element very quickly.

3) How long is the cord? what gauge is the cord? If its too long, the voltage drop could be enough to not cause the block heater to fully warm up. This may also cause the cord to overheat, does it feel warm?

Check to make sure the cord is still plugged into the block heater, maybe it popped out if the cord isn't well secured.

 

Running the block heater without water around it will burn it out. Use an ohm meter, and check between the hot and neutral pins on the plug, it'll probably be infinite resistance.

 

There is an insulating coating on the element. If the element touches the block, vibration and thermal expansion will eventually wear through it and it will short to ground...

 

Well I did the quick continuity test of the plug end tonight when I got home and it was at like 650, not infinite, but a heck of a long way from 0. I'm going to check the pins on the heater itself at some point to be completely sure, but I think I'll wait until it isn't dark, 26 degrees outside, and snowing for that part.

 

It should be in the 10-14 ohm range, for a 1000W, 120V heater.

650 ohms means it's shot; it would only be producing 22 watts of heat, if that numbers even real.

 

It's just my luck something stupid like this would happen. Brand new $60 heater and $70 worth of brand new antifreeze and it took a s$#t already... So I can do it all over again. Does anyone have experience with the lower radiator hose heaters? I'm considering this as apposed to another freezeplug style. It'll be easier to get to and install and less prone to leaks... Remember I'm in PA so I'm not dealing with 30 or 40 below zero, just looking for something to ease those 15 or 20 degree mornings.

 

I used one on my Courier with the 2.3 with good results in -20 Idaho winters, so it should work ok. Just make sure to put it in the vertical section of the hose, if it's in the horizontal then it won't be as effective. An air hole in the thermostat will help tremendously with the circulation too.

 

Still haven't gotten to this yet since I made other advances with new batteries and such but I'm still considering. Anyone else have experience with lower rad hose heaters? What about circulating tank heaters? I've been looking at those as a fairly cheap, easy option. Please let me know what ya think. All answers and opinions are valued.

 

To me, the lower rad hose heater seems like it might lose a lot of heat through the radiator.

Two other posts appear to back up my theory.

The tip on installing the rad hose heater on a vertical part of the hose.
A valid tip I'm sure, this would help the rising heat go to the block, rather than the radiator.
And,
Drilling a hole in the thermostat.. To help with convection flow of the coolant. And that flow would flow into the radiator... Also drilling a hole will allow coolant into the radiator while it's running with the thermostat closed. That thermostat is closed while it's running to keep the heads hot so the fuel will burn... A hole in the thermostat defeats That.

I like the idea of a circulating heater on the heater hose. The heated coolant can circulate in the heater circuit and through the engine. When the truck is not running, with zero vacuum the heater blend doors will default to defroster setting. The heated coolant in the heater core might convect some heat accidentally through the defroster and began defrosting the windshield. Maybe, even heating the cabin a little...

Another heater I've thought about is a magnetic block heater. Not being a permanently mounted, it could be moved from vehicle to vehicle ....

 

I am personally a fan of things working the way they were designed to work. A 1000 watt heater inside the block of your engine is awesome when it works correctly. If it were me I would test ohms on the pins of the heater. 10 - 14 ohms like Macrobb said sounds right, definitely not more. Test the cord seperately for continuity, should be at or near zero ohms end to end. Whatever part is bad, take it back and ask for an exchange. I know it sucks. I had to install mine twice to get it right. I used clean 5 gallon buckets to capture the antifreeze and a plastic water pitcher to pour it back in. This is just my opinion but I say hang in there and you'll get er done.