# Ram diesel cold start problems



## Ducati 851 (Jan 3, 2015)

Here's a question for any mechanics out there...my 03 Ram diesel won't start in sub 40 degrees day unless plugged in. Previous to this year, would easily start in sub 10 degrees temps. I drive a Freightliner with a Cummins in it, and it will start,albeit hard, when cold and not plugged in. My mechanic friends who work on diesels have no answer. Originally thought it might be a fuel issue, such as lower fuel delivery because of clogged filter.....put new filter in couple thousand miles ago. More of a interesting question quandary than problem, will make sure I plug in. But, why is this happening with no other changes?


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## Blizzard1980 (Dec 27, 2012)

Ducati 851;1917199 said:


> Here's a question for any mechanics out there...my 03 Ram diesel won't start in sub 40 degrees day unless plugged in. Previous to this year, would easily start in sub 10 degrees temps. I drive a Freightliner with a Cummins in it, and it will start,albeit hard, when cold and not plugged in. My mechanic friends who work on diesels have no answer. Originally thought it might be a fuel issue, such as lower fuel delivery because of clogged filter.....put new filter in couple thousand miles ago. More of a interesting question quandary than problem, will make sure I plug in. But, why is this happening with no other changes?


Grid heater issues?


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## Ducati 851 (Jan 3, 2015)

Don't think so......used to start even without cycling grid heater


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## leolkfrm (Mar 11, 2010)

how old are the batteries....sometimes the batteries get weak and you dont realize its not turning as fast as it should


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## MIDTOWNPC (Feb 17, 2007)

Ducati 851;1917199 said:


> Here's a question for any mechanics out there...my 03 Ram diesel won't start in sub 40 degrees day unless plugged in. Previous to this year, would easily start in sub 10 degrees temps. I drive a Freightliner with a Cummins in it, and it will start,albeit hard, when cold and not plugged in. My mechanic friends who work on diesels have no answer. Originally thought it might be a fuel issue, such as lower fuel delivery because of clogged filter.....put new filter in couple thousand miles ago. More of a interesting question quandary than problem, will make sure I plug in. But, why is this happening with no other changes?


I have a 03 also and you should be able to hear if the grid heater kicks in and see the lights dim a bit. if you cycle the key for a warm up a few times will it still not start.

you can bump fuel to it by just turning key and letting it go over once. turn off do again. Its injector fuel related not fuel pump related in my opinion.

if one injector is faulty an 03 will not fire in cold. had this issue myself.
replaced the injector and it was fine. #2 was faulty

check for codes? on off on off on with the key. look at the odometer and write them down and google them

I bought from dieselautopower.com
good guy.

I did all the injectors on mine and I still use that truck today. 495 000 kms
bought it with 80kms 10 years ago.


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## jhenderson9196 (Nov 14, 2010)

You can confirm a bad injector with a rail pressure gauge or scan tool. The computer requires approx 5000psi rail pressure while cranking to fire the injectors. If one or more have a high return rate it won't make enough rail pressure while cranking. Plugging the truck in warms all components and in some cases closes tolerances enough to mask the bad injector. It also helps the truck crank faster which makes more rail pressure.


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## Ducati 851 (Jan 3, 2015)

Thx for replies. Injector issues were a thought, but not throwing a code, yet! My mechanic is thinking fuel related, so injector on it's way to being bad sounds possible. Don't think it takes much to make a difference in starting. Our old straight trucks in work have the 5.9 Cummins and they will not start in the cold without plug in. Funny my big 11 litre always starts, and that doesn't even have any grid heat or anything. Thx again, will look at injector issue...


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## 04trd (Sep 21, 2013)

How many miles are on the truck? Does it run fine other than the hard starts? If it does i doubt it will be fuel related. I've got a 7.3 and it has glow plugs and if there is a problem with the glow plugs the truck won't Fire when it's cold. Not sure how a cummins works you guys are throwing the word grid heater, I would look there first.


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## Cover Guy (Sep 30, 2009)

Check the grid heater but you probable need new injectors I had the same issues with one last year


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## jhenderson9196 (Nov 14, 2010)

IT ain't no stinking Ford! Doesn't have glow plugs and doesn't need the grid heater to start. The heater is there as an emmissions requirement.


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## SnoFarmer (Oct 15, 2004)

jhenderson9196;1917719 said:


> IT ain't no stinking Ford! Doesn't have glow plugs and doesn't need the grid heater to start. The heater is there as an emmissions requirement.


Then why don't all of them have a grid heater?
And i think they had them before the EPA?

It should still start at any temp with out it ,it's just much easer to use it if it has it

So how do you get it started, if it doesn't start below 40*F?


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## Ducati 851 (Jan 3, 2015)

SnoFarmer;1917746 said:


> Then why don't all of them have a grid heater?
> And i think they had them before the EPA?
> 
> It should still start at any temp with out it ,it's just much easer to use it if it has it
> ...


Grid heater is like a toaster element, it warms the intake air to ease cold starts. With the electronics, truck can still run OK if an injector is not quite up to snuff. I am plugging in to start now that it is cold all the time......THX


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## jhenderson9196 (Nov 14, 2010)

1: all of them don't have a grid heater because not all diesels are direct injection. Ford and GM are indirect, that's why they need glow plugs. 2: the EPA has been around longer than a Cummins in a pick up. 3: no heavy equipment that uses the 5.9 ( logging, mining, earth moving) has used a grid heater until tier 4 emmissions became law. They all start at -25F without it, but do produce smoke until a little cyl temp is made. Maybe you should stick to snow farming, seems to be your stronger suit.


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## dieselss (Jan 3, 2008)

Ford and GM are indirect, that's why they need glow plugs.

They WERE, not any more. They are direct now...Since 97 on the Ford's and since the dmax on the gm? And they both have glow plugs.


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## jhenderson9196 (Nov 14, 2010)

No pre chamber? I stand corrected. Why does a DI diesel require glow plugs?


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## dieselss (Jan 3, 2008)

Same reason an idi needs glow plugs. To create heat. 
Some factors include, compression, ignition timing, psi of the fuel delivery, and amount of fuel being injected.
Some engine manufacturers used a fuel fired intake type heater, and some solely relied on starting fluid.
While I'm not anywhere near a Cummins expert, fault injectors might be a place to start. As well as your fuel return issue he spoke of.


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## dieselss (Jan 3, 2008)

jhenderson9196;1918100 said:


> No pre chamber? I stand corrected. Why does a DI diesel require glow plugs?


Di.....direct injection, no prechamber
IDI....in direct injection, prechamber

Ease of starting as I said.


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## SnoFarmer (Oct 15, 2004)

yes, first the op has several threads open on this.
He needs to get a handle on his fuel return issues.



Ducati 851;1917785 said:


> Grid heater is like a toaster element, it warms the intake air to ease cold starts. With the electronics, truck can still run OK if an injector is not quite up to snuff. I am plugging in to start now that it is cold all the time......THX


He has injector issues because his fuel psi is to low.
IE he has a leak.
THX, thanks I've been wondering what that thing was for 38years.
What was in my post that lead you to believe i didn't know what a grid heater was?

huummm ,i only plug in if I'm going to use it, and if the temps are below 9*f.



jhenderson9196;1918079 said:


> : the EPA has been around longer than a Cummins in a pick up. 3: no heavy equipment that uses the 5.9 ( logging, mining, earth moving) has used a grid heater until tier 4 emmissions became law. They all start at -25F without it, but do produce smoke until a little cyl temp is made. Maybe you should stick to snow farming, seems to be your stronger suit.


:laughing:

The EPA was proposed by President Richard Nixon and began operation on December 2, 1970.
The use of grid heaters predates the epa..

tier4 emmisions.
NOX,& SOX, egr,dpf, urea,cat, and the grid heater was already in place to be used by the new computers to aid in starting, coming on automatically, no longer being a choice to use it or not to use it by the operator. They also use egr right after start up t0 raise temps, when latter it will be used to lower combustion temps.


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## Randall Ave (Oct 29, 2014)

Your intake heater needs to work. But you need to connect to a good scanner, run cranking fuel pressure. If it is not up to spec, it will not start. If it is low, you need a special cap for the fuel injector feed rail. This lets you check individual injectors while cranking watching live data. If you find a suspect injector, then you can check fuel return rates. If you have an injector leaking, it may not throw a code.


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## jhenderson9196 (Nov 14, 2010)

Sno Farmer, tell us all what Cummins engine used grid heaters before the first gen Dodges used them in the late 80s. 

Randall Ave, why do his grid heaters need to work ?


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## Randall Ave (Oct 29, 2014)

The intake heater will aid in his cold starting, but I do not think this is his main issue. Until 
he runs some tests, we are all just speculating.


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## jhenderson9196 (Nov 14, 2010)

The heater grid is emission related. No other 5.9 application has had them installed until required by fed vehicle emission standards. As I have pointed out many times , no off road application used them until tier 4 standards took affect. The engine will start without grid heating down below 0F without starting fluid. I know because I own and operate them every day. Have for over 20 years. You are correct when you said more testing. In my 1st post I told the OP to run a rail pressure test and the probable outcome. Then he got conflicting info from people who don't really know Cummins common rail engines. Hope he can weed out the BS.


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## Ducati 851 (Jan 3, 2015)

Luckily, I have good ******** detecting skills.....you guys really take this **** seriously. I do appreciate it. Been driving BIG truck Cummins for 30yrs. Am not a mechanic, but my friend who is our fleet mechanic will certainly be able to diagnose. Our 24' straight trucks run the 5.9 and now the 6.7....same motors as our pickups. No grid heaters or glow plugs. And, a real ***** to start after they get a little old.


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## Randall Ave (Oct 29, 2014)

Snap On tools sells the rail caps, I got mine from the company that makes them for Dodge. Your larger trucks may have 5.9s, but might not be common rail. I wish you were close, I have a new snap on scanner I would try on it.


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## Ducati 851 (Jan 3, 2015)

Big trucks have an 11 litre I think. Will ask my buddy if he has the tool.....if not I will see if Cummins will let us use one. Fairly good relationship with them, got many thousands of their engines. THX for the info.


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## SnoFarmer (Oct 15, 2004)

tire 4 doesn't mention a grid heater, nor glow plugs,
They are a starting aid, 
Any dttitional soot produced by starting without the aid would be taken care of by the PDF or scr system.


And mine will start with out using the grid heater or starting fluid


Again the use of grid heaters and glow plugs per dates tier4
And the creation of the EPA

I can see we're it would be a up grade to a power unit.
As it would shorten warm up and the engine would be is service quicker


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## jhenderson9196 (Nov 14, 2010)

We're talking Cummins. Tell me. What Cummins used grid heaters before an 89 dodge pickup. And explain to me why the grid heaters are covered under the Federally mandated emissions warrenty.


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## SnoFarmer (Oct 15, 2004)

jhenderson9196;1918963 said:


> We're talking Cummins. Tell me. What Cummins used grid heaters before an 89 dodge pickup. And explain to me why the grid heaters are covered under the Federally mandated emissions warrenty.


Yes we are talking cummins so don't play stupid.
Glow plugs, starting fluid, grid heaters ect ect are starting aids.

Tier4, as your always going to that, wasn't even a thought in any ones mind in 
89.

Show me your proof.
As I cited my source earlier.


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## SnoFarmer (Oct 15, 2004)

http://www.csemag.com/media-library...ing-cost-effective-compliance/15eb2f8716.html

^ This address emergency standby generators.......
hummm no mention of grid heaters........

http://www.csemag.com/single-articl...llenges/9ab23a8f9225fd9aec743c5ac34f707d.html

http://www.epa.gov/midwestcleandiesel/publications/webinars/merkel_cummins_repower_web_092210.pdf

^right from cummins , humm not one word about a grid heater.

and Ive been searching for" epa emission requirements , grid heater" with no luck.

You could be right but i have found nothing.

ps no one has failed a emission test because of deleting the grid heater nor were they flanged because of it.


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## jhenderson9196 (Nov 14, 2010)

I asked you to tell me what Cummins motor used grid heaters before a 5.9 in an 89 dodge. The grid heaters are there to reduce smoke on cold start in the pickups. If hey we're needed for cold start they would be on every 5.9. Non to be found on off road or marine applications. Some tier 4 apps. In off road MAY use depending on chassis mfg emission equip. As far as failed emission test, a visual insp. is supposed to be done. If the heater is missing it's not supposed to pass. Now tell me, which Cummins used a heater grid, and why warrenty coverage for them comes under emission equipment warranty. By the way, I'm not playing stupid, you refuse to answer my question about prev Cummins motors with grids. And I suspect you'll continue to do so.


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