Cumminsdude

I read that cummins use something called a grid heater and I was wondering what that was. I heard that cummins start easier in the winter. Cummins must still have glow plugs but is this grid heater on all dodge's? Thanks

Shovelhead

The Grid Heaters on our Cummins are used instead of glow plugs for cold weather starting.

They heat the incoming air before it hits the cylinders with what resembles a couple of toaster elements in the intake tract.
Look at the base of the intake horn, you'll see several large wires connected to terminals with nuts and washers.
These are the heater's electrical feeds.

Them heatin' elements pull about 750 watts each.
This is also the cause of the infamous "Voltage Dropping at cold start-Up".

ed

Monty

To add too Shovelheads comments. No Cummins engine that I am aware of uses glow plugs . From the A series all the way up to the QSK models in mining and trains.

Cumminsdude

oohhh, I see so they dont have glow plugs. Now this must mean you have to have a pretty healthy battery or two batteries, dont they have two batteries? This could be a pain in the neck if your battery was dead.

Commatoze

[quote author=Cumminsdude link=board=8;threadid=12654;start=0#119498 date=1048442369]
I read that cummins use something called a grid heater and I was wondering what that was. I heard that cummins start easier in the winter. Cummins must still have glow plugs but is this grid heater on all dodge's? Thanks
[/quote]

I'm confused at your question because you first acknowledge that Cummins' use grid heaters, then say they probably use glow plugs. ??? Cummins uses a toaster-like element called a grid heater which heats the intake air. When the engine is cranked, then hot air is pulled into the cylinder making starts very easy way down below zero without the aid of a block heater.

Cumminsdude

oh see, I thought you had to have glow plugs to ignite the fuel? sorry for the confusion, I am new to diesels but very interested and I love the sound and power they have but would love to know how they work you know.

Commatoze

[quote author=Cumminsdude link=board=8;threadid=12654;start=0#119504 date=1048443057]
oohhh, I see so they dont have glow plugs. Now this must mean you have to have a pretty healthy battery or two batteries, dont they have two batteries? This could be a pain in the neck if your battery was dead.
[/quote]

Whether it's glow plugs or a grid heater, both pull copious amounts of current, and you'll find 2 batteries in most diesel vehicles for that reason.

Shovelhead

See here for how diesel engines work.<br>http://auto.howstuffworks.com/diesel.htm

Cumminsdude

ok great thanks for all the help. How does the fuel burn? There arent spark plugs right? Also what is an exhaust brake? I want my truck to be able to idle until it gets up to temp because I sometimes drive short distances but I will let it warm up but I hear people saying dont let your cummins idle and all that so what should I do? Dont they make on the big trucks where when you turn the key off they actually stay running until they are up to temp or the turbo is cooled down? Thanks for all the help guys. Sorry for such stupid questions

Cumminsdude

oops sorry, I posted that before I read the link. SORRY BUT THANKS FOR THE LINK....VERY HELPFUL! Thanks shovelhead<br>

Cumminsdude

ok another question.SORRY but would a cold air intake help a diesel? I mean its more air but its cold and the idea is warm compressed air right? I would think it would help because the turbo is all about air and the more air the better. Also what is the exhaust brake?

Shovelhead

No Problemo.<br>The only dumb question is the one that's never asked. 8)<br>We're all here to help, and have fun learning.<br><br>Ed

Shovelhead

This'll give a basic idea of how an exhaust brake works.

http://auto.howstuffworks.com/question134.htm

Ours uses a butterfly plate in the exhaust system to achieve the resulting backpressure.
Cooler air is good, to a point, once the engine is warmed up to operating temps.
REAL cold air can reduce the engine's ability to stay in it's happy temperature range leading to inefficient fuel burn.
It's a delicate balance.

Ed

Cumminsdude

Maybe I am not understanding this right but the way I read things it sounds like you shouldnt let your truck idle too long unless you have an exhaust brake. What does the exhaust brake do that allows you to leave your truck to idle for longer periods of time. Also can you put and exhaust brake on a 2500 oe 3500 and how much do they cost?

Shovelhead

You can idle a 24valve engine for longer periods of time in colder weather if you use a high-idle system to raise the idle speed to 1200-1400rpm.
My high-idle system in a stick cut to the proper length that when placed on the throttle pedal, and the other end on the seat frame, raised the idle to 1200 rpm.
The engine temps must be kept up to ensure all fuel introduced into the combustion chamber is burned to prevent the unburned fuel from washing the oil off of the cylinder walls, or allowing varnish to accumulate on the valve stems, causing seized valves/galled valve guides.
An exhaust brake creates backpressue holding some of the combustion temps in the chamber.
It's not advisable to use an exhaust brake with a stock auto tranny.