Silly question about block heaters

To set the question: I have a 1986 Ford that now has the 7.3 (6.9 give up the ghost, so, I repowered it) IDI non turbo.. It has been hard starting in the cold lately, so, the last few nights I been plugging it in.

I currently don't run the block heater on a timer, but thinking I might try to find a timer today, as I can see it getting expensive leaving it plugged in for 8-12 hours a day. If I get a timer, the question becomes irrelevant.

The question is: Should I plug it in when still WARM.. Like just got home from class or supper or.. and I know I'm in for the night, or should I let it cool, then plug it in???

I have a friend who claims you should never plug in a warm truck.. I don't see what difference it makes, other than the water is warm, so it more will "maintain" a warmer temperature as opposed to warming up freezing cold liquid.


Brad

It makes no difference at all if plugged in with a warm or cold engine. A frost plug heater or a tank heater, makes no difference. Frost plug heater runs at low wattage all the time (unless on a timer). Tank heater turns itstelf off via a thermostat.

When ever somebody tells you something like that, ask for specifics as to why.

If you haven't bought any glow plugs in a long time, the ones Ford sells now are much better. Made by Beru in Germany and stuck into Motorcraft boxes. 6.9 and 7.3 IDI engines are usually very good in cold starting when all is right.

When I dropped this engine in, I checked the glow plugs "by the book" and all checked as "working".. It was sometimes hard starting since go.. they all still seem to check "ok" but the cold starting seems to be getting worse.. My connections seem sound, and the voltage seems to check ok, again, according to book.

I'm sure it needs new glow plugs.. The 6.9 would always fire great.. no matter the temperature after the new glow plugs.

Problem is, I'm unemployed for the winter (as I am most winters) so money's tight right now.. at least till income tax time.. Or until we get a good spell of weather to work a week or 2.

Brad

Let me check around. If I have any new ones I'll send them to you, if you pay postage. That's if I can find them. I just sold my 85 F250 with the 6.9 and have no use for the plugs anymore. I have two newer 7.3s, but the 1987s and newer use different ones.

If I find them, I'll repost here later. Your 6.9 uses the same plugs many GM diesels used.

1983-1986 6.9 Ford IH and also 82-83 Buick, Chevy, Olds, Pontiac 4.3 and 5.7 diesel, 79-83 Cadillac 350 diesel - all use the same glow plugs.

Delco 8G, Beru 0 100 271 102 or 835MJ or GV835, Bosch 80024, Autolite 1107, Wellman GO80 or dual coil GO88, Champion CH80, Ford and Motorcraft ZD1A or E5TZ12A342B, General Motors 5613680, IH/Navistar - 1804211C2, Lucas/Delphi DS090A, Delphi HDS305.

A frost plug heater will keep it warm with less cost. The tank heaters lose a lot of heat from the heater & hose.

I have a simple little timer that I just now plugged my truck into. I have it set to come on about 2AM. That way I can plug the truck in anytime, but it won't start heating until it's on the night rate. Then 5-5:30 in the AM when I'm ready to go, it fires right up.

Buddy of mine tried a timer on his and never had much luck with it workin write. I have an 04 250 with a 6.0 and an 87 with a 6.9. You are absoulutly correct about how much electric they draw. I like to plug mine in before I go to bed and then Ill unplug it when Im gettin ready to leave for the farm in the morning. If I know that Im not goin to drive it anywhere for a day or two I just dont plug it in. It seems with both my trucks and when I had my 7.3 you really only had to have it plugged in for an hour or two and thtas all it needed. The way i do it works for me and my electric bill is definatly lower than when i just left it on all the time. Before you wonder how I know there is such a difference well I have a seperate service and meter for my garage than the house and thats were my truck gets plugged in at and other than the truck there isnt anything to draw anything outthere cause i shut off all the other breakers when im not out there.

You may also want to check the glow plug timer on top of the engine in the back. Ive seen them short cycle and not heat the glow plugs. My stepdad had a 91 ford with the 7.3 non turbo with 600k miles. i replaced at least 2 timers in its life. also had to repair the wire that feeds the timer. had got hot and melted and messed up the timer. Just my 2 cents. not worth much.

No such thing on an 86. Engine mounted electronic controller came out in 1987.

86 uses a thermal-switch screwed into a coolant-port into the intake manifold. Same as used in the early 6.2 GM diesels.

I checked around in my "junk box." I've got four new Champion CH77 glow-plugs and four new Delco 9Gs. You can't use the 9Gs, but the CH77s are fine.

I checked the specs and the Champion CH77s should be fine for your 6.9. If you want them, pay the postage and I can stick them in the mail.

To be honest though, the Beru plugs that Ford sells are much better quality and are pretty-much burn-out proof. That's what GM sticks in Delco boxes also.

I suggest you hook power to each plug though an amp-meter- just for a second and check amp draw on each plug. That will tell you if bad or not.
Your plugs are rated 9 amps.

Ford-IH up through 1986 takes plugs with these stats. If you were using Delphi brand, your truck takes a HDS305. Made for a "12 volt system", plug marked "6 volts", operating voltage is 9 volts, draws 9 amps, takes 50 seconds to reach full heat at 6 volts, threads are 10 mm X 1, heater-element depth is 26.5 mm.

HDS305 12 6 9 <50 @ 6V <50 @ 6V .375" 10 x 1.00 80 mm total length, 26.5 mm depth

The Champion CH77 is built to the following specs:

HDS306 12 6 9 <50 @ 6V <50 @ 6V .375" 10 x 1.00 77.5 mm total, length depth 26.5 mm depth

They are exactly the same except the Champion stands out a little taller by 2.5 MM (3/32").
The installed depth of the heating element is actually the same length.

I bought an intermatic heavy duty appliance timer (Ebay for about $12.00) to use on my F350 7.3 diesel. Works just fine, but it's not weather proof. Do not expose to rain.

I've got the HD Intermatic timer I bought new in 1979. I use it in my chicken coop to turn the lights on and off in the winter (to keep them laying).

So, it's over 30 years old and still works fine (makes some noise though). Must be all mechanical.

I wonder if the new ones last even half as long?

Now are those the same for the 7.3??

The 6.9 had "spade" connections, and i was always told they are 6v..
This 7.3 has the round "bullet" connections, told they are 12v

I have the 7.3, and I have the "intake mounted" controller.. Somedays I wish I had swapped over all the 6.9 starting aid stuff, but I was ASSURED the 7.3 would start even better..

14 months after the engine swap I AM STILL NOT IMPRESSED!!!

Brad

It has nothing to do with the engine you stuck in.

It all about how much you swapped over from your 6.9. 6.9 and 7.3 are the same engines. 7.3 just has a sligthly larger bore.

6.9s up to the end of 1986 use the thermal-controller and the HDS 305 glow plugs.

6.9 in 1987, and the later 7.3s (1988-1994) use the electronic controller and HDS 307 glow plugs.
Same as Delco 32G, Champion CH84, Beru 0 100 271 101, Bosch 0250 202 254, Ford Motorcraft ZD9, Lucas DS092A, etc.

I have no idea how much of your original truck wiring you kept. Maybe that's your problem?

Would that 7.3 engine by any chance be out of a 1988. We got 1 and never has started as good as our 6.9 or our 1992 7.3. Dealer has replaced everthing top of that engine and says 1988 had the glow plug offset from earlyier and later . To fix we would need to replace heads. It only has 80000 miles on it cause when It gets down to 30degrees it gets parked.

How would the block heater know if the engine was warm because of just being run or if the heat was from the block heater itself? It's not going to heat it up to running temps, just keep it warm enough for an easy start. I think your friend is nuts on this.

A lot of truck owners in this area use timers - most set them set them for about 2 hours before startup.
Just make sure the timer is rated for your heater.

Brad. A block heater works on the same principal as a water heater element.Keeps water warm from a warm engine,just as a water heater keeps water warm while in the tank.Only difference is a water heater uses thermostats to control the on off cycle, while the engine frost plug heater hasn't any built in thermostat.The tank heater does have a thermostat,much like a water heater in the home.
LOU.

If we're both around in 30 yrs and I remember, I'll let you know.

I'm sure that someone more mathematically inclined than I, can run the numbers, and find out what the amount of energy times the kilowatt hour price comes to. I run a 300 watt freeze plug heater on my Cat 3013, cause it's the loader that I feed with. I think someone calculated the price at less than a quarter a day, a while back, but I could be wrong.

JD: I DID NOT use the 6.9 glow plugs and controller.. I used the unit that belongs on the 7.3

I did, however, wire it just as Ford recommends.. 4ga wire from battery to controller, IGN power source to controller.. exactly as it was in the truck it was removed from.

I CAN HEAR THE CONTROLLER do it's thing.. Comes on steady for about 30 seconds or so, then cycles off and on 5 or 6 times (which is USUALLY an indicator that one or more glow plugs are not functioning as they should, per a IH/Navistar mechanic)

The controller has proper voltage in and out, per the service book, and proper voltage to ALL glow plugs. I don't suppose that means that there couldn't be a controller issue.. Maybe not "cycling" for a long enough time, I don't know. Don't necessarily mean the gp's aren't "weak" either.. I'll check them out after this next cold spell.

I know everyone thinks I'm some backyard HACK.. But, alas, I am not.. I do things per the service book.. YES, I BUY MY MANUALS!! I don't start asking what I consider stupid questions.. I do my homework, then ask if I get stumped. As a matter of fact, the how much oil, what kind of oil, where is my fuel filter, etc. questions really pi$$ me off.. BUY a D@MN BOOK and READ IT, then you don't have to ask.

I know the block heater question was a dumb one, but, as I said, I have a friend (who drives truck) and he claims that if he plugs the block heater in while the semi is warm, he's lucky to get a season out of the block heater.. I too, like a couple other posters, think he's crazy, which is why I asked the question.. I think he has a different issue somewhere, but hey, what do I know.

As to the poster who asked, I cannot recall now if this engine is from a 87, 88, or 89.. may very well be a 88.. and I have never heard about the gp's being in a "different" location.. I'll ask some questions and look into it..

Sorry for the long post, and sorry if I came off as an a$$.. I'm just sick of a truck that won't start.. Plain and simple.. Drove it with the 6.9 for a LONG time, never plugged it in.. NOT ONCE.. This 7.3 so much as hears cold forecasted on the radio and it wants to hibernate.. Runs like a top, once it starts.. and as I said in a post the other day.. once it starts in the morning, and it runs till warm, you can shut it off for 4-5 hours, fires right up, no issue.. I'm seriously at a loss.. I just don't know what to try next.

Brad

Not enough difference to worry about.

Not enough difference to worry about.

I have my snow blower tractor and Diesel pickup plugged in 24/7 in the cold weather. The extra electric for both is less than $30 each month. I may get a call at any time to come blow someone out so the tractor may need to go ASAP. The truck is my insurance against needing to get someone out in an emergency.
Many years ago one of my neighbors had a heart attack in the middle of the night. We had blizzard conditions that night. None of their tractors would start as they had them on timers. They called me and I was able to blow the road out plus their lane so the life squad could get him to the hospital. It was only luck as I had been using timers myself until just a few days before. Mine had burnt out and I had not replaced it. It made me think real hard about what the savings would be verses being ready in an emergency. I do have the other things on timers but not those two things. They are on a thermostat. When it gets above thirty degrees they shut off.

What ever the case. Good to see somebody using an
engine heater. Instead of extended cranking sessions
which wear out the starter, battery & alternator.
Ether, jumper cables or tow starting are silly too.
The immediate heat to the windshield defroster
beats idling the engine for 10-20 minutes wasting
$$$ fuel on warmup. While causing extra engine wear.

Well if I ever have a glow plug issue I know who to get hold of. LarryT

93 7.3 idi turbo.....I just give a shot of you know what into the air inlet when its cold.....
Block heaters in the freeze plug seem to heat the motor faster than the heater hose type to me...
Used to have a couple farm tractors with them in the bottom radiator hose,,They seemed pretty good also...

When I worked in a fleet truck shop, The trucks were plugged in when the driver parked it, and un-plugged BEFORE they started them. It seems the life was shortened if left plugged in when the engine was running. I was told it was because of cavitation.
Me, I'd plug it in when parked if it was cold enough to make starting hard. My wife also likes the heater blowing warm air as we leave the driveway.
Tim in OR

6.9 diesel, I had problems with my 86 f250 with glow plugs. I replaced the glow plugs and a good mechanic here put in chevy parts to run the glow plugs and it started good. I wish I had the old truck back. I bought a 01 with 7.3 and is hard to start too when it is under 35 degrees. It has a flat bed on it which I really like. when I bought it I had problems with the auto tranny. When I went uphill with a trailer with out lights it would shift up instead of down. Had to change the tail lights from LED lights to regular tail lights. Now the tranny works good if I get the darn truck started in the cold weather. I do use a block heater too. It helps a lot.