Hello all,

I have a 2003 Duramax, currently at 172k, all stock drivetrain 4" lift with 35s. I had Injectors replaced around 150k 2 months before warranty expired, that was 2 years ago now.

I am currently having a couple problems but let me go back a bit... I was having a problem with low coolant occasionally, so I kept adding some until it got to the point where it was every other day to get to work and back (30 miles round trip). I replaced the water pump and it went back to the every few months adding it. It is getting a little more often again every few weeks I have to top it off, never a light just the warning message low coolant message.

Over the last few months I have started to have a bit of white smoke at startup until it warms up but never seemed much worse than the other cars steam on the road...

I noticed it was starting to get a little harder to start a few months ago probably around the same time as the white smoke. 3 weeks ago I rented a trailer from uhaul and it drained my batteries... Killed them. So I replaced the factory batteries. It was time...

Anyway now when I try to start it when its cold it starts to crank and sometimes suddenly stops after a few turns like it hit something solid... maybe a full cylinder ? Bad starter?

This only happens in the morning or after sitting for a full day at work etc. Anyway about 2 weeks ago right after replacing the batters the temperature dropped into the 30s and the white smoke got bad, a solid cloud for say 3-5 miles on the freeway doing 80... each morning it does this now until it clears w/e out and warms up but seems to run perfectly, no engine codes etc...

I let it sit for about 5 days over the break and went to start it and it did the usual rough start but died, had to re-prime the fuel filter. this happened to me once before randomly at the grocery store, tried to leave and it started up for about 10 seconds then died, had to prime fuel filter to restart it.

Today it was in the 60s this morning and still left a major smoke cloud for ~2 miles and on top of all of that for the first time today I noticed a lack of power getting on the freeway this morning, the first time i stepped on the gas hard, this was about 1/2 mile from my house. I was stepping on it and the rpms were increasing but in the low 2ks it seemed to have a sudden lack of power so I basically backed off the throttle, waited for it to shift and got back on it a bit and everything seemed fine for the rest of the day.

I was at work for 1.5 hours then had to run an errand and it started fine, no smoke, no power problems...

At this point im half afraid its a head gasket and injector combination but please chime in... I will check the condition of fluids tonight, I know I am well overdue for a fuel filter change and I poured in fuel injector cleaner about 3 weeks ago when I was replacing batteries. I am down to a 1/4 tank from that tank.

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So I checked the upper radiator hose before I went home and it wasn't rock hard.

When I got home I noticed that I could hear the radiator was venting pressure, I could hear it from in the cab when I turned it off, it lasted for 10 seconds?

I picked up a fuel filter on my way home and changed it and topped off the radiator (Though the fluid looked like orange coolant and some rust mixxed and there was some black specks coating the inside of the resevoir, im sure it needs a flush but? The Oil seemed ok, not sure how to really tell if there is fuel in it...

This morning it started fine and no smoke.

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I guess yesterday was a fluke. Last night I filled up and added fuel injector cleaner again... This morning the truck is already showing low coolant, and it smoked again like it was for a good 3-5 miles on the freeway and had a hesitation cranking again...

 

So I topped the coolant off again last night and bought a new resevoir cap, I let it run with the cap off to see if it dropped again. It kept filling up, overflowing, dropping, then fill up, overflow and drop way down and repeat. It spit just about everything I put in out... So I put the cap on and turned it off. Of course the low coolant came back on this morning... but less smoke this morning, so it seems it doesnt smoke if I release the pressure to the tank at night... What do you guys think?

 

kinda sounds like an intermittent head gasket leak to me...

 

2nd that, you cooling system should have no leaks or missing coolant.

white smoke from a diesel can be atomized fuel that is not burned (temps are to cold) or air in the fuel can also cause this.
in your case, im thinking you are seeing water vapour that is leaking into the cylinder.