Cold weather starting problems

[Mopar1973Man]

On 12/25/2016 at 6:50 PM, Mopar1973Man said:

There is a lot of factors that affect starting performance. Injectors, compression, valve lash, cetane number, grid heater performance. There is many more. I've done cold starts many times at -20F without much issues. I can explain better when I get home to keyboard.

 

 

 

Ok let me explain a bit more... General requirements is compression and fuel. Now with temperatures in the minus numbers your grid heater function is very important to feed heated air to the cylinder for better compression temperature. Now the fuel is also very cold and typically already winterized #2 diesel or #1 diesel is used. So the ignition quality is already present.  The problem is guys with larger injectors tend to have larger droplets size and with very limited heat of the grid heater they typically have more starting issues than stock or smallish injectors.This why a lot of guys have to plug in there block heater through the winter as a requirement because of starting quality. There are some of us that can start very good down in the minus numbers. Again its about the quality of the fuel mist and how fine you can make it, how much compression heat you can make (with the grid heater alone), and you fuel quality (cetane) if it capable of igniting easily at minus numbers. 

 

Now you can see bad valve lash could affect the valve timing and compression quality. If you already got excessive blowby (worn rings) then compression quality will be down. Grid heaters are ran on a timer from the ECM so if the batteries and or cable are poor quality then the amount of grid heater heat will be reduced and make starting more diffcult. Starter speed will also impact compression quality being these truck can draw up to 700 amps DC they are power hungry when cold. Again battery cable are very important to have less than 0.2 voltage drop while cranking. Bad starter contacts and or brushes can and will slow cranking down considerable.

 

I've done it several times this year with hauling cows and hay where I left my truck parked in New Meadows, ID in minus weather come back hours later and just fire it up like it was no big thing. Like this fall I knew my starter was getting weak in the brushes and needs to be rebuilt so I've installed a new NAPA starter and not had a single starting issue as of yet.

Edited December 30, 2016 by Mopar1973Man

[Silverdodge]

 

3 minutes ago, Silverdodge said:

I live in central WI and I've started mine block temp of 5 outside temp negative 15 or so degrees cycled the grid hit the starter till it fired let off maybe 2 seconds of cranking didn't stay running did that 2 times on the 3rd time cycled the grid b4 every cranking and she started no issue and I got 200 horse ddps so I'm happy with that i definitely noticed a difference cold weather starting with this truck compared to my old truck with 150s now quick question could I just fire the grid 3 times back to back then start I've only cycled 2 times befor at once and just curious here 

 

Edited December 30, 2016 by Silverdodge

[Mopar1973Man]

2 minutes ago, Silverdodge said:

I got 200 horse ddps

 

There is why your starting quality is lower. The larger droplets are fairly large and hard to ignite. You need more heat or more compression. Here we come back to guys requiring a block heater more than I do for cold starts.

[Silverdodge]

2 minutes ago, Mopar1973Man said:

 

There is why your starting quality is lower. The larger droplets are fairly large and hard to ignite. You need more heat or more compression. Here we come back to guys requiring a block heater more than I do for cold starts.

Not complaining mike just stating my experiences since I'm in the same state but I was figuring I usually don't plug it in until 15 degrees ambient temp

[Mopar1973Man]

No biggy... Just pointing out why the harder starting issues. It good to use your case as an example. Most of the place I go with my truck there is no power to plug in the block heater anyways so... I've got to keep that in mind during my modification thoughts. As for cold air this is pushing the limits for ignition quality. 

[Silverdodge]

Ya I hear ya I can plug it in at work and my apartment so I'm happy it starts better then my buddys stock 6.0 powerstroke at 15 degrees and his is stock lmao 

[WiscoRedkneck]

7 hours ago, Silverdodge said:

I usually don't plug it in until 15 degrees ambient temp

This is what I tend to do and as long as it's above 10 degrees ambient once the truck is fully warmed up, I usually can start easily without even waiting for grids for 6 hours past shut down.  It will need to sit for at least 10 hours before I think about plugging back in.

Now for your information when Cummins went through the top end and installed the turbo they informed me that I had stock injectors still in the truck, meaning my current injectors likely have 315,000 miles on them. 

Do you think I could have issues there as well besides the grid heaters and block heater?

I plan on messing with the block heater more tomorrow found nothing conclusive yet.

Edited December 30, 2016 by WiscoRedkneck

[Silverdodge]

Injectors could have clogged or nozzles went bad 

[Mopar1973Man]

4 hours ago, Silverdodge said:

Injectors could have clogged or nozzles went bad 

 

315k... I would say the injectors are tired.

[WiscoRedkneck]

Good to know, thanks,  it makes me chuckle a bit thinking I live by the adage "let sleeping dogs lie"  and for that reason alone is why I don't change parts until they break(sometime biting my butt for doing it), I know my truck starts better than a lot of others around here(in summer) and I haven't had a problem until now so the injector thought had never crossed my mind.

[Haggar]

One thing I think i noticed in this thread,

 

Double check the batteries!  Part of the compression formula is speed.  Cranking speed comes from voltage.  Older batteries or poor connections, cause a higher voltage drop so starting speed drops....  (we also have the cold oil and other higher mechanical drags.) 

 

I was hoping there was a cummins spec sheet like on the stationary motors showing minimum cranking speed.   It seems we need at least 150rpm and closer to 175rpm. 

 

You may want to warm your batteries.  That may make a big difference. 

 

Here is a neat sheet attached on calculating what size batteries we need

 

and here is a nifty video on voltage drop

 

Hope you get it figured out!   I have a couple batteries here at the house right now (not including the ones in the truck)  That will hold 12.6 volts all day, but the minute I try to start, they drop to about 6v....  If the car lights off  I am in good shape, but if for some reason I need a second crank, they won't make it.....

 

Happy New Year!!!

starting amps calculator.pdf

 

Note, at about the 9 min mark they show a list.  It says if you drop below 9.5 during cranking, batteries are bad.  ( looking for a voltage/speed curve for starters...)

Edited January 3, 2017 by Haggar
added voltage note

[Mopar1973Man]

Very good video @Haggar  

 

Works off the same idea of the voltage drop test that I've got in the article page.

[LiveOak]

I leave a charger/maintainer on both of my batteries and plug in my block heater at least 4 hours before I attempt to start it.  Both of my trucks set for long periods and that can be hard on batteries.  You would be surprised at the voltage drop due to extreme cold weather.  With a fully charged & topped off battery I get the maximum output from by grid heaters.  The block heater warms the cylinder head to where I can feel the change in temp with my hand.  I find that this almost always makes for a fast and nearly immediate start.  Fully charged batteries WITH CLEAN, CORROSION FREE connectors on BOTH ends of the cable (ie: starter end as well) is a big deal.

[AH64ID]

In terms of testing the block heater just pop the hood and touch the block. It should be at least noticeably warm where the heater is. 

 

The windchill won't have an effect on the temperature but it can have an effect on the efficiency of the block heater. I highly recommend some sort of winter front to help keep the heat in. This will also help warm the intercooler and batteries, both of which will help with cold starts. 

 

As far as the oil, yes 5w-40 is needed when temps are that cold. It will not effect the starting ability but it will effect oil pressure after startup. Even with a block heater I wouldn't run dino 15w-40 that cold even with most of them having a pour point of -25-27°F they just don't flow well below 0°. 

 

My synthetic 15w-40 has a pour point of -36°F and when the block is 0° it takes about 6-8 seconds to get good pressure on the on drivers side of the block. I've done a freezer test at -5° and there is a huge difference in dino and synthetic 15w-40's. 

[LiveOak]

One other thing I forgot to mention is that I have winter grill loover covers installed on both of our trucks.  This helps to hold what heat the block heater generates in, under the hood and also helps to reduce cold air penetrating into the engine compartment once under way.  I bought them from a guy who sells them over on TDR. 

[CUMMINSDIESELPWR]

brutus spent better part of 10 years in colorado and i will say one big factor to cold starting is good batteries. i feel mainly to be able to spin the engine over fast enough to get compression fast enough to get good detonation of fuel.  and this of course after a round or two of grid heater cycles...

 

in wisconsin last winter it was 7degF out and truck didnt want to start. turned over but died quickly...  ok so i tossed a solar charger on it and let it sit for a couple days, i went to start him up, (it was colder and no block heater) and one grid heater cycle and he fired off like it was summer temps...  the solar charger topped the batteries off well!

[Me78569]

Good batteries are key when it comes to getting an engine to kick off in the cold.  

 

Diesel needs heat to combust, the speed at which you compress the cylinder will have a great impact on how much heat is created.

[Mopar1973Man]

You can have 4 batteries producing massive power. But if your cables, terminals, starter are all junk it won't matter how much power your batteries have if you can't deliver to the starter without huge losses. Most trucks I've seen the cables are junk and the starters are marginal at best. This is why person like myself with bit over 800 CCA batteries can start easy in minus weather. Very minmal losses from the battery to the starter and grid heater.

 

Edited January 4, 2017 by Mopar1973Man

[WiscoRedkneck]

Happy new year hope all is well.

Update, I have found a few things, thanks for the pointers along the way.

1. Grid heater relays are fried, wiring was questionable at best.  The relays shorted internally this melted post relay wiring and relays, pre relay wiring is corroded beyond repair.  The grids have been removed, the relays were hitting 130f and above so I was fearful of other damage...  I will have new relays on Friday, I will be installing and rewiring this weekend.  The grid heaters themselves have not been tested, that will happen this weekend, as well I hope they are not damaged. 2. Batteries and most wiring tested out good and passed voltage drop test, not surprised  FYI when I got stuck I had started 3 times and had over 2 minutes of total crank time when you add up all the attempts and the forced oil prime.

3. Block heater may be routed incorrect it comes out by my passenger front tire, but is working, tested this morning.

4. I found the cord I used that day works in the perfect position but a little jiggle and it breaks connection.  I found this after using it today with my circle saw to cut lumber.  

So my two cents do yourself a favor, plug a hair dryer or electric appliance into the extension cord you intend use turn it on and shake the cord if the hair dryer or electric appliance stays on your good if not replace the end, heavily used cords will wear out internally. 

5. Injectors, lash, and compression are not part of the current issue.  I'm still south and this morning it was +4F truck fired off first try, only issue was oil pressure (read on) and no grids FYI.  It will not be above +10F until Sunday.

6. Personally for me the 15w-40w dino oil has got to go even with the block heater after 6 seconds I shut down due to no oil pressure and restarted immediately I had pressure 4 seconds after that start.

 

 

Edited January 4, 2017 by WiscoRedkneck
Typo

[AH64ID]

Glad to hear you are making progress!!!

 

Good call on ditching the dino 15w-40, but I think you're probably better off letting it idle for 10 seconds than start/stop and still not getting pressure for 10 seconds. It will take the same amount of time either way.