Jerry,
I have a 2001 F-150 with the 5.4 L V-8 engine and about 65,000 miles.
Haven't had your problem with smoking at startup (or any problems for that
matter), but I did notice that it burns fully synthetic oil, but not regular
oil. I think that somehow the synthetic gets past the rings and goes out the
tailpipe, but that regular oil doesn't (bigger molecules?). I can go 5,000
miles without adding any oil using regular 5W30 oil, but have to add a quart
every thousand using synthetic.
In the winter when I'm not towing I'll use the 5W30, but in the summer when
I am towing I've used 10W40 without any problems. I was told by Ford that
using a "heavier weight" oil will not invalidate the warranty. The lighter
viscosity oil can be used because today's engines have tighter tolerances,
and I think Ford only recommends it because it helps save fuel during
startup by reducing friction quicker.
I'd push Ford into fixing the problem though - if you're the original owner
the factory warranty should be 100,000 on the power train, yes? Perhaps it
is the extended warranty that is reluctant to pay for the fix? Of course, if
you have been towing beyond the stated rating of the 4.6 L package that
might invalidate the warranty. Looking at the chart I have the max trailer
towing weight for a 4x2 with 4.6 L engine and automatic transmission is
2,000 lbs. for the 3.08 axle, 6,200 lbs. for the 3.31 axle, 7,200 lbs. for
the 3.55 axle. Subtract from those weights the weight of any cargo carried
in the truck itself. The max trailer towing weights are less if you have a
4x4, a SuperCab or SuperCrew.
By way of example, I have a 4x2 SuperCrew (5.4 L V-8), but with the optional
factory tow package, which gives me a max trailer towing weight or 8,500
lbs. I tow a 1966 Globe Trotter, that weighs in at 3,500 to 3,600 lbs.
loaded. It would seem that I'd have a huge surplus of weight towing
capacity, but after I've loaded all the accessories and other stuff in the
bed of the truck I'm within a couple hundred lbs. of the vehicle's max gross
vehicle weight (don't forget to add the weight of the driver and passenger).
The only way to know for sure of your weight is to go to a certified scale
loaded as you'd normally be when traveling. I'd bet you're at or over your
maximum, unless you tow a vintage Caravel or Bambi. The new Bambi Safari, or
International would be too much for the 4.8 L engine drivetrain IMHO.
Forrest