When to plug in a diesel?

[never]

I have a Duramax and don't ever plug it in...always starts right away. Tell him to try not plugging it in and see if it starts.

[speedog]

Originally posted by never
I have a Duramax and don't ever plug it in...always starts right away. Tell him to try not plugging it in and see if it starts.

It did start at -7C, just belched a bunch of black smoke plus it didn't warm up as quick as he would've liked.

Like I said before, what's a "realistic" temperature to be plugging in a 2002 Ford 7.3 liter diesel - a temperature where it may not start if not plugged in. Chugging away and belching back shit isn't the issue here.

[never]

Diesels don't ever warm up that quick.

I'd just say don't plug it in at any temp until it has starting issues...then you have found the point where it would need it.

[89s1]

I plug in my gas engine vehicle at anything below minus 10, even though it is parked indoors in the garage. why? heater blows warm air much quicker as the coolant begins well above ambient. It's also much easier on the engine to not have to pump molasses around as lubrication for the first 30-45 seconds.

My block heater is an element like in a kettle for boiling water, stuck into the water jacket, so it warms the coolant.

Call me a wuss but my back gets really stiff if it's cold in the car.

[Unknown303]

Originally posted by never
Diesels don't ever warm up that quick.

I'd just say don't plug it in at any temp until it has starting issues...then you have found the point where it would need it.

He should get used to driving a cold vehicle if he wants a diesel. They take forever to warm up. Or he's going to have to run a aux electric heater in the cab to warm the cab up quicker.

[firebane]

Originally posted by speedog

It did start at -7C, just belched a bunch of black smoke plus it didn't warm up as quick as he would've liked.

Like I said before, what's a "realistic" temperature to be plugging in a 2002 Ford 7.3 liter diesel - a temperature where it may not start if not plugged in. Chugging away and belching back shit isn't the issue here.

Sounds like he probably also has it tuned to be an ass on the roads which probably doesn't help either.

[speedog]

Originally posted by firebane
Sounds like he probably also has it tuned to be an ass on the roads which probably doesn't help either.

He's had it for all of two days, tuning is most likely still to come.

[My_name_is_Rob]

While I don't have much experience with the 7.3's, it seems the less maintenance a diesel receives, the more they need to be plugged in. I plug my diesel in usually below -15, my one room mate, with a newer less maintained cars plug in around -5 to -10. And my other room mate, with an incredibly unmaintained Cummins has to plug in anywhere below 5 degrees. If he doesn't plug it in for at least 3 hours, it doesn't start.

[AllGoNoShow]

^^ +1 7.3s lacking maintenance can be a bitch to get going once they are cold. Just go buy him a timer and put it on 4-5 hours before he needs to go to work.

I plug in the 6.4 below -10 where I can, Yes it starts in -40c but if I can save a $10k+ motor job or extend the life of the truck by letting the oil start warm in the morning, that's a plus in my books. Less wear & tear, less chance of not firing, less chance of not making it to work.

And for the guys that don't think it warms the truck up any faster, start your truck -20c with no block heater and see how long to warm up to temp at idle and once you get going, then do it again -20c with the block heater plugged in, your already 30% warmer and truck will get to temp in less than half the time unplugged, no it doesn't blow warm out instantly but that isn't what it's designed for, if he wants that get him to buy a diesel coolant heater so it isn't your bill and runs on his diesel.

http://www.espar.com/
http://www.webasto.com/us/markets-pr...ating-systems/

[RickDaTuner]

A Ford 7.3 uses a HEUI injector system; which literally use oil pressure to fire fuel into the combustion chamber, This coupled with the fact that a diesel will only combust when the air inside the combustion temperature reaches a certain temperature from compression, is what causes a great deal of miss informed people to do silly things with their diesels.

Normally the intake air temperature on most modern diesels is raised by the use of intake heaters, the 7.3 if it hasn't been modified has one of these systems present.
Some guys claim that the heat shock to the glow plugs is too great when you hit -10 and bellow, because they go from ambient to 600c in about 15 seconds.

If the diesel in question has higher kms, and the hydraulic injector drivers are worn, this will result in the residual oil leaking out from the injectors after the engine is turned off, then having 15w40 oil cooled down to -10 causing it to become sluggish, the further end result will be an extended crank to re pressurize the HEUIs so that they can fire fuel into the chamber.

your roommate basically just needs to run synthetic oil, and add a bottle of diesel oil conditioner every other oil change, then the system will work just fine. plugging in at -7 is a bit silly, were not running diesels from the 70s anymore which had no intake heating devices.

Fuel additives can help on older trucks, but its far better to just keep water out of your system, and have fuel filters changed regularly. cetane boosters can damage the particulate filters of the modern diesels

[spacerz]

As a couple other's have suggested, if the truck has higher KM's- the injectors or injector o-rings are worn out. I had a similar issue with my 02' 7.3 (370,000KM), when I had them replaced, it started just fine.

[italianstylez]

My Ford didn't like to start at 0 plugging it in when its -7 or colder is pretty average

[ddduke]

How much extra would it really cost on your electric bill if you just let him plug it in? I'll be gone for months and use nothing at home then when I'm back plug in my vehicles, run my computers 24/7, play music, bake my meats daily, etc. and I don't notice much of a difference.

I know you're one of beyond's grumpy old men that likes to complain about everything but is it really worth the stress? Just let the guy plug it in and stop losing sleep over it, you'll be a much happier person that way.

[speedog]

Honestly, I'm not losing any sleep over this - I'm just trying to educate myself with regards to this particular diesel engine model and it's real requirements. It needs to be noted this individual wanted to plug in their last vehicle at -5C so it they'd have a cabin that would be warm in a shorter amount of time and this individual fully admitted it was for their own selfish reasons.

[racerocco]

A factory 7.3 1000watt diesel block heater would cost about $1 to run 8 hrs. If it's that big a deal just bill him for the time he wants to plug it in...

[speedog]

Thank you racerocco, that is great information and puts things in a new perspective. Now I just need to positively suggest that he get his 290,000 km diesel tuned up and do all the others things that are needed to ensure that it starts in the most efficient manner - it does appear that he probably bought a bit of a beast with respect to cold/cool weather starting.

[legendboy]

Originally posted by speedog

Why?

Educate me as I'm not a diesel guy.

I baby mine but diesels are very high compression. Combine that with cold starts = premature wear on piston rings = smoking diesels you see everywhere

[speedog]

Is it a safe bet to say that at the 290,000 km that's on this 7.3l diesel, that it probably has a bit of wear on the piston rings and elsewhere?

[Alak]

He needs to run 0w40 oil. 15w40 moves very slowly when it's cold (that's an understatement). If I was running 15w40 I would probably plug it in around -15. If I was running 0w40, probably -25 or colder. My work truck runs 0w40 and I never plug it in. With good batteries and a couple glow plug cycles it fires at -35 provided the fuel filters are clean and the oil is clean.

I have a block heater timer to come on about 4 hours before I get up in the morning for my personal truck. The block heater heats the coolant in the block. The it warms the oil through conduction.

I'm not sure how the 7.3 is for cold. both my work truck and personal truck are 6.0.