cold start problem

[caissiel]

This morning I had to use the 87 Turbo diesel to boost the 2005 Ford, that refused to start, I have 15 / 40 Rotella T in it, because I planned to spend the winter in florida. The truck would start but as I released the key of the start mode it would not keep running. I had to try 4 times before it started. It is very funny to see the $200.00 diesel VW used to charge the batteries and boost the $25000 Super Duty. The VW started right off this morning with 15/40 Oil in it to. It was 5 Deg F outside. This same thing happened to me 2 days ago but the batteries allowed it to start on its own. It seam that the oil is to tick and does not fire the injectors. What will it be if the temperature was much lower. What weight of oil does Ford put in it, is it 5/30 or 10/30. I always use 15/40 in the winter in all my diesels for the past 15 years. Found the 5/50 synthetic would make my VW hard to start because the compression would not build up fast enough. With 5/50 I had to plug them in while with 15/40 they start right off at any temperature. GM was the same for me I never plug them in ever.

[mtman]

My '04 manual specifies 15W-40 above 30 unless heavy towing, then above 10. 10W30 preferred for 10 below to 30, but ok to 90; 5W30 below 30 and 0W30 below 0. Mine is a lot harder to start when cold than say 70 degrees and that's with it plugged in. Took 10 minutes today to start nearly.

[caissiel]

what grade oil are you using. I always faithfully used 15/40 diesel oil. I might have to dump this oil and place 0/30 oil in for a month then. Its bad when you have to to be so fussy with 16 Quarts of oil. Might have to use my 87 VW for the fall because I can't trust this Ford

[mtman]

I have 15W40 in mine right now. I'm new to diesels and not to thrilled about how difficult it is to start in winter. Have you run a diesel additive/injector cleaner recently? It might help. If I can get my oil leak fixed, I'll probably put 10W30 or maybe 5W30 in it, although I'm a little leary of going below 10W30. A friend of mine from Minnesota has had Fords over the years and never changed from 15W40 even at 40 below so I'm wondering if it's a 6.0 thing. Good luck.

[vitalidle]

I know the manual doesn't specify it and neither does ford, but I switched from 15w-40 to 5w-40 rotella last year and its a night to day difference

[mtman]

So you cranking time diminished? I think 5-40 is synthetic right?

[vitalidle]

Yeah sure did and the engine smooths out so much quicker when its cold. Also seemed to quite down the injectors as well. Yep its rotellas synthetic.

[vitalidle]

We have been single digits to teens at night for a few days now and I have yet to plug the ole girl in yet

[vitalidle]

Oh and another reason I like the oil is it doesn't start to look dirty till around 4000 miles. The 15w-40 was dirty after 1500-2000.

[mtman]

Do you have the 7.3? How often do you change your oil? Over the past week it has been down to 10 below here, but even in the low 20's it took almost 10 minutes to start with it plugged in. One thing to save the batteries though is to not over crank and give it a bit of a break between cranks.