I have been looking all over this web site for info to help me with this problem. I have a 2004 F-350SD with the 6.0. I bought it back in Feb. We have had some very cold days here in the last few weeks. My problem is my truck won't start unless I keep trying for about 30 mins. Of course in that time I have draged out my starter unit to keep the batties from dying out on me. It will start running after a while and will smoth out. This is why I don't think it is a fuel issue. If the fuel was gelled it wouldn't start at all I would think. I have tested all the glow plug at the gpcm. Every one of them is in range from .6 to 1.0. I checked the B+ voltage on both plugs and it comes back with the same rating as the batteries. I checked the switch voltage and it too is good. I put it all back together. Then I pulled the connectors on the top of the motor that go down to the glow plugs. I have voltage there. When the key is turned on the voltage jumps to battery volts. In about 1.5 mins it drops about a volt and stays there. When I shut the key off it still shows voltage. Maybe I am not test it right I don't know because I can't find anywhere on here how to test the GPCM. Should there be voltage with the key off? Should there be voltage after 1.5 mins (unless its colder. I do know the timer can go up to 120 sec)? Can someone please help me or point me in the right direction?

 

Things I forgot to add.... I am running 15w-40 motorcraft oil. It was about 6 degs outside at the time.

 

Ouch, wrong oil... I wonder if your cold & thick oil is having a problem circulating through the HPOP.

Did you check your FICM yet?

 

Have you tried plugging in the block heater over night? How many miles on the truck. Any smoke while cranking the truck. Try waiting 30 seconds to a minute after the glowplug light goes out before cranking the truck. While the oil is thick at that temperature and may give you some injector stiction while warming, it shouldn't cause you that kind of starting difficulties, however 5w40 would be a better choice in those temps.

 

Are you running anti-gel in the fuel? If it's that cold?? you need too.

 

Yes I have power service in the tank. I don't think it would be a gelling issue since it will start and stay running once you get it started. I took it to sears yesterday and they found one of the batties had a problem so I had them change out both. I also stopped by the auto parts store on my way home and they are out of 10w-30 (havn't been able to find 5w-40). I guess I will try that next since it hasn't been above 32 for weeks now. Yes when I plug the heater in it starts easier. Oil is next. Also... No white smoke just a lot of black smoke. I have to hold my foot on the floor until it starts or it will die out. Once it starts I have to feather the fuel until it smoths out.

 

All wally worlds sell synthetic diesel motor oil 5w-40