Cold Start in Cold Weather Issues

[DenaliHD66]

I've never really had a problem with my 4WD, but any time my truck sits outside in the cold weather, and I turn it on, sometimes it won't let me shift out of 2wd and it says Service 4WD on the dash. The actuator light just blinks for whatever setting I put it on. Just kinda sucks because otherwise I have to warm it up a good 10-15 minutes (driving) before I can turn it on. The other day I was leaving work, and the roads were snowy and icy, so I turned my truck on, and started driving through the parking lot, shifted into A4WD, and it didn't engage, and the Service light came on. So I pulled to the side and shut the truck off (I've turned it off before, and restarted it and it would allow my 4wd to engage then), but this time, the truck wouldn't restart. It took about 10 different cranks for it to finally start back up... so about 5 minutes total had passed. Was my engine "flooded" because I turned it off while it was still revving high to warm up?

 

[The_Roadie]

I don't have much to say about the failure to start except to ask about the mileage and did you change the plugs at 100K and is the throttle body clean?

I have seen and repaired a sluggish front axle actuator that was overfull of non-synthetic grease from the factory, that failed in exactly that way when cold. Replace it unless you want to use my pictures from trailvoy to rebuild it.

Lastly, I've recommended for years to not use the risky A4WD mode. It's risky for the transfer case, risky for breaking you loose when it engages, and is basically useless except in very rare and specific road conditions. If it's slippery enough to need 4WD, go for it and use 4HI. If it's merely rainy, use 2HI and drive without pushing it to the limit of adhesion.

 

[DenaliHD66]

Yep, everything new and cleaned and maintained. I barely ever use the A4WD. I just like to engage it first, then bump it over to 4WD if I really need 4WD. Instead of jumping 2 selections at a time, ya know? But anyways, been running a lot of cleaner through my intake and fuel system to repair a misfire on #5 (carbon buildup on valves?) and so maybe it had an effect on the non-startup.

 

[CaptainXL]

Lastly, I've recommended for years to not use the risky A4WD mode. It's risky for the transfer case,

I always tell the wife to put the selection knob to A4WD if there is snow on the road. Never had a problem with it myself. It does stay bound up sometimes if you accidentally leave it on in A4WD transitioning from snow packed roads to wet roads. As Bill said, probably better to leave it in 2WD for just wet roads. But my wife doesn't understand going back and forth and the conditions that warrant a change between modes. So I made it easy for her. I drive it mostly in 2WD and the G80 locker is often more than enough.

 

[TollKeeper]

It probly has the same problem my Envoy does, a bad front axle actuator. A very common problem for the 2004 model year. Theres a thread around here somewhere, and it has some good info on it.

I am willing to bet that if she were to let the truck warm up, and then select the 4wd/A4wd, that it would not throw a code. The actuator is getting gummed up with grease more or less, and warming it up thins it out.