[VAL] Old Diesel Trucks

[Mark Pate <spectrumnc@xxxxxxxxxxxxx>]

Hi All:

Got in late on this thread, but I specialized in old Ford Diesels for 
years. The pre-'88 trucks are all 6.9L, which are just as expensive to 
replace as a later normally aspirated 7.3L. Both rebuilts are in the $5-7K 
range, easily totalling the truck should engine failure occur.

An '85 F250 diesel 2wd with 200-300k miles is worth around $2500 around 
here (NC). $900 for any one that runs is a good deal, the engine is easily 
worth that much, the transmission and rear end are worth that much as well. 
The only way I would not be highly suspiscious of a truck this cheap is if 
the body is damaged or rusted.

At any rate, on most of the old trucks I do the following: 1)Check the oil, 
see if there is any discoloration. Any milky looking substance is an 
indication water is getting in the oil, probably a head gasket, which 6.9L 
engines are very prone to do. 2)Look for smoke out the tailpipe. Obviously 
diesels smoke black, especially older ones with no Cat. White smoke can 
indicate either water in the cylinders, leaking injectors, bad injector 
pump. 3) Check the condition of the rest of the drivetrain - transmission, 
u-joints and rear end. These components are no more expensive than a gas 
truck. 4) Don't be surprised if it doesn't crank the next morning after you 
buy it. Most of these old trucks need glow plugs and timers, and for some 
reason the folks that have these trucks think it's easier to use starting 
fluid. 5) Unless you know the person selling the truck, do not believe the 
mileage. These trucks have 5 didgit odometers that have spun around many 
times. I know of an '86 6.9L still running around here with the original 
engine and 400k+ miles.** If there were ANY problems with the engine or 
transmission (like an automatic slipping) there is no way I'd hook a 
trailer up to the truck and haul it the distance you described.

Lastly, if I bought such a truck and was going to drive it the distance, I 
would fully service the engine. The 6.9L trucks of that vintage have 2 
seperate fuel filters, one for water on the firewall (lots of folks take 
these off) and one on the right front of the engine. If the transmission 
were an automatic, I'd service it as well.  I'd take a long hard look a the 
belts and hoses. Check the mileage on your odometer when you fill up. You 
should be able to get at least 225mi/tank. I say this because the fuel 
guages on the old trucks are prone to be inoperable, and you DON'T want to 
run it out of fuel. Ask any of your friends that have diesel cars or trucks 
how much fun that is. The floats and sending units are $200/each, plus you 
have to drop the tanks to install. Those old trucks have 5 belts on them 
rather than the one serpentine belt on the newer trucks, and they jump 
around all over the place when the truck is running. If one goes, they all 
go. Any other items, unless completely shot, can be replaced when you get 
it home. I don't like to do major work on any vehicle prior to taking it on 
a trip. I like to drive around town a few days to make sure everything is 
ok.

The good part of the old trucks, though they don't have the power of the 
new DIT's, is the fuel economy. I regularly got 18mpg overall, and well 
over 20mog on the road with a 6.9. The powerstrokes I've had struggle to do 
14-16mpg. Hope this info is helpful. If you need to ask any more specific 
questions, feel free to contact me off list.

Mark Pate
Spectrum Automotive
Stanley, NC