Hello everyone

thanks for all the advice I’ve got on this forum so far. Looking for insight on another issue here.

The previous owner of my truck lived in a warm(er) region than me and neglected the starting system. I live in an Extremely cold area, so once winter hit, I could not get the thing to start. I found many things were weak or non-working and replaced them:

- batteries
- alternator
- glow plugs and relay
- starter (a 6.7 PSD model)
- block heater

After this work, if I have a plug-in available I have no problem down to about -20F. No plug-in is okay to about +5F. But any colder than that makes for a sad powerstroke, and it does get a lot colder here so I gotta do something about this. Plus there is not always a plug-in around.

I have to try cranking multiple times, sometimes get a boost, and once it starts it runs very rough for a few minutes. During cranking, it sounds like the injectors are struggling to fire, or the fuel is not combusting. Wisps of smoke in the exhaust after cranking, occasionally one or two cylinders will fire once and then nothing.

I am aware that the GPR stays on longer than the dashboard light, I’ve checked the GPR and glow plugs with a multimeter, everything checks out. Injectors all sound the same on a buzz test. This is about the extent of my knowledge but I’m sure you folks can help me figure this out before next winter. I have Forscan available for whatever testing is needed.

 

what oil do you use?
air intake heater working?
what is your cranking RPMs when cold?

 

I run Rotella T6 5-40 in the winter.
I forgot to mention I also replaced the air intake heater and its relay. I thought it was an essential starting component but I’ve since heard that it’s not

RPMs when cold, I couldn’t tell you. My estimate right now (being 75 degrees out) is about 350 rpm? The 6.7 starter sounds much faster than my old starter. I am aware the computer needs to see 100 rpm and I was certainly above that in the winter with the new 6.7 starter.

May be worth mentioning that when I went to start the truck just now to check this, it had been sitting for ~7 days and I had a longggg crank to get it started. Big puff of smoke when it finally started, then quickly cleared up. I hadn’t done any work with the oil or fuel.

 

X2 on the oil. When winter hits for sure better have 5W-40 in there. How's the battery cables look? Might look into up sizing or adding additional wires between the battery and starter and the GPR. More copper means less resistance means more amps can get to where you need them.

 

They’re most likely the same ones the factory put on 20+ years ago. But they don’t look corroded or anything. I suppose a replacement wouldn’t hurt.

 

long crank after 7 days
hmm

see if oil pressure goes up fast or slow next time it sits a few days

mine goes up in a rev now with a new oil pump, before it would take a few revs if it sat a few days

 

I put a heater on the engine oil pan,
it has a thermostat that kicks it off just above 160*
with the block heater and that oil pan heated up,
it should start like it was sitting in Mexico City.

back in the '70s, I worked in NW Utah and Temps went down to -59*F and stayed there for more than six weeks. the '74 Suburban with a 454 engine, would not even rotate, without the heaters turned on.

I also put a 2nd heater on the transmission oil pan, can control it separately with a toggle switch.



while working there in NW Utah, I flew a company airplane, a Piper TriPacer
those have Air Cooled engines.
We used a 1500 watt floor heater, bypassed the Tilt Switch,
placed it under the engine, and then wrapped the engine with a Furniture Blanket pad....

put a Timer on the heater cord, it would turn on at 3 a.m. and by 8 a.m. when we needed to go flying, the engine oil temp gauge was on 160*

Prop the engine over twice w/o Mags on,
then Mags on, and prop it over once, and Varoom

 

Any way to test this without waiting several days?

 

Sure that would help at extreme cold… but relying on extra heaters because your truck can’t start at 0F is a band-aid solution… something is not working properly on my truck and I want to fix it

 

A dedicated oil pressure gauge w/ actual numbers on it could help give an idea of the health of the pump. There is a spec for hot and cold oil pressure. Going from memory so grain of salt here, but cold is 30-40 and hot is 10-20 at idle. Another thing you could check is the hpop reservoir. Before the first start of the day just pull the plug on top, the level should be within an inch from the top. If it's low then the lpop is having to fill it before the hpop can get oil to fire the injectors.

 

You're not going to like this, but with diesels and hard cold starting you need to make sure the basics are 100%. What gives them ignition is high compression super heating the air in the combustion chamber to bring the temperature above the ignition point of the injected diesel fuel.
I'm recommending that you get a compression tester and go through the diagnostic procedure to make sure that your engine has the proper ignition above all else. No "band-aids" in the world will cover up a basic loss of compression and resulting no-start for a diesel engine. That one thing is the most important part in finding out what is causing the long cranks.

 

hey,
cool off a bit,
just offering a possible solution.
for me, my truck is bone stock with 178k miles on it,
when the temps drop below 35* it is hard to start....

when I turn on the block heater, it pops right off...
it starts and runs smooth as glass when the temps are above 50*F,
to assist in turning on the block heater, I bought a Thermostat that switches on 120VAC to the heaters at 46*F.... that way I don't have to remember, " did I plug in the heaters? "

I want it to last me a long time, without spending my retirement check on foolishness like new injectors when the ones that are in it, perform just fine, in warm weather.

 

Okay, I’ll have to order a diesel compression tester because nobody has one within 300 miles of me. I’m a little skeptical because you would think low compression = low power? I’m having no issues with power. No noticeable blow-by so no concerns with the piston rings… although I’m aware there’s other places to be losing compression… but I feel like I would have noticed low compression while hauling my camper up mountain grades.

I’ll still check it out, this is just my thinking on it.

As above, I’d have to order an oil pressure tester… I’m in the largest city for 300 miles and yet nobody seems to sell simple diagnostic tools except for Napa, who never has them in stock anyway.

I’ll take a look at the hpop level. Would hpop issues cause low-power symptoms too? I’m not having issues with power at all… once you get it started (and slightly warmed up) it runs and pulls like a top. I’m hesitant to to point the finger at things that should affect hot-engine performance too.

Anything else can be checked while waiting for tools to show up? Can forscan show us anything useful?

 

No offense intended… in all politeness that’s just not an acceptable solution for me

 

I live in northern Maine, so I deal with the <-20F stuff on a regular basis.

The most impactful thing I have done is to install an onboard battery tender. When at home I keep it plugged in all the time. It does a good job for me that I haven't been compelled to replace the batts the truck came with (its an AZ truck). I had this tender installed on my e99 and again I never felt the need to upgrade the batteries to get me through the winter. I find that I don't have to run the block heater until -25F or so.

I also have to deal with my truck sitting at the nearby airport for 3 weeks when it is very cold. For that I got a good quality jump box. I slap that thing on right away before I even turn the key. So far I haven't had a problem, although it does protest when it doesn't have the benefit of an hour or two with the block heater plugged in.

I did upgrade my entire charging system wiring in the e99. But my 2002 AZ truck? I haven't had time to do so yet, but it did make it through its first winter on stock wiring.

So to hedge your bet in a very cold climate: 5w40 oil, upgraded/up sized battery/charging wiring, battery terminal isolation switches (for those times your rig sits for awhile away from a plug), and a battery tender. Also, make sure your auto headlights are not engaged and everything is off before you crank.
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