Hi, just bought my first diesel. So anyway it has the 6.9 idi in it and 167k miles. This isn't my first truck and I live in the mountains so I am used to the driving style. I was curious about the following,
What normally should I watch?
I want to keep the truck stock, I don't mind going slow, is there any issues with that?
Is the stock C6 as reliable as I have read? I cruise at about 55 mph at the most.
The truck I got seems very well maintained. Oil is just oil and the antifreeze looks clean. No colors out of the smoke and it sounds just like a diesel. Click,click,click,click...
Any advice is apreciated, elevation here is about 4,600 ft and it gets cold if that is important.

 

make sure your coolant has the proper SCA's in it.
a 6.9 are not prone to cavitation, but a good thing to keep up on.

make sure your glow plug system is in perfect order.
motorcraft glow plugs only!

keep your fuel filters clean!

other than that, enjoy!

if you find any fuel leaks...
address it right away. air intrusion can be a pain!
there not like gas trucks where it can leak a bit and youll be ok,
air in the fuel = issues.

 

Thank you, I'll keep that stuff in mind. Will definately check for fuel leaks. I appreciate it.

 

Any fuel leak will allow air to be sucked into the system and the engine will be hard to start and produce some gray smoke. Most often the leaks are in the return fuel lines and the caps at/between the injectors, sometimes at brass flair fittings (O-rings in them) - don't tighten those too tight or they will break! (use flair wrenches - for tubing connections if you have them) but leaks can be anywhere in the fuel lines back to the tanks. LOTS of information in these forums so search those out - It's probably covered well in the Tech article in the 'Read First' section at the beginning of the forum. Very common problem. Return fuel line replacement kit's are readily available - I bought on-line.

If you like to do nice things to your truck: I drained the C-6 including torque converter, cooler in the bottom of the radiator & aux. cooler, added Full Synthetic fluid AND BY THE WAY, MERCON V Definitely IS fully approved for use in all Ford transmissions prior to about 2006 or maybe 2008. There was a technical service bulletin from Ford about that time stating this specifically. You will read many times in the forums where people say MERCON V it is NOT to be used but that is obsolete information. Mercon V is better than previous automatic transmission fluids. I used the full synthetic with much better performance characteristics.

I also installed an external MAGNEFINE filter in the rubber return cooling line, the TRUE MAGNEFINE, not the look alike copies which are not made as well. $26 online. THAT is an amazing little filter! I also installed a larger auxiliary transmission fluid cooler because I'll be hauling some weight and a trailer over a few mountain ranges. The factory one was small and it was plugged off because of leaks. If you'll be hauling significant weight in the mountains you might consider a better cooler- original is probably fine for typical use and hauling if it is in good condition. I expect my C-6 to be very nice to me and last longer than I will. this is how I mounted my larger cooler:
https://www.ford-trucks.com/forums/1...er-cooler.html

In Minnesota during very cold winter weather I blocked off some of the air flow to the radiator to assure that the diesel I had then would get up to normal operating temperatures for the driving that I was doing. (see temp gauge comment further below)

Next time I do an oil change I am going to use full synthetic with a special filter AND add rare earth magnets from old computer hard drives placed outside of the filter housing to duplicate the Magnefine concept- these are available commercially but too expensive for me!

Other than that, check the rear brake adjustment- sometimes the automatic adjusters don't work, and just basically follow the recommended service intervals for most things- those intervals are increased considerably by doing what I mentioned above. The MAIN thing that most often gets neglected is greasing (and inspecting) the chassis parts, steering etc. under the truck. I think that would be especially important in your Montana climate.

The BEST glow plugs would also be essential in that environment and those are Motorcraft/Beru ZD9. Beru manufactures them for Motorcraft. Maybe the previous owner knows if that is the brand you have in which case you won't have to mess with them. If it ever doesn't start like it should you can test the GPs with a test light. (it's usually air in a fuel line or bad GP(s).

I would advise that your temperature gauge be working- if not, fix it - (replace the RIGHT temperature sender) or upgrade the gauge to a better more accurate one.

Front end alignment check.

By now all of this will be adding up to considerable money spent. I don't mind because I like fixing up my old truck :-)

 

Diesels are not driven like gas engines, (RPM range, torque & HP relationships and shift points are different) but you will get use to it if you are mindful of these things. Lots of info in these forums. If you put more fuel to the engine than it can efficiently burn then much will be wasted as un-burnt fuel and come out the exhaust as black smoke. Sometimes this might be necessary for a little bit more power and acceleration, especially in the mountains to get up to speed quickly but I personally love the performance of diesels and driving them when the fuel air mixture is perfect. I'm not a diesel hot-rodder but must admit I've experimented a bit to see what my 6.9L can do on a steep grade, empty, and I LIKE what it did. Injection pump timing will affect these things too but you probably won't need to mess with that at all-

 

The stock C6 is pretty much bullet proof, if it has been taken care of. As far as synthetic goes, to each his own, I have an 86 6.9, went to synthetic and it leaks more than it burns. Take a look at your engine, if you already have oil leaks, you will have a lot more using synthetic.

 

Thank you everybody, I appreciate it. It definately takes some getting used to. The truck doesn't seem to have any real issues. It goes around town just fine, and I am pretty sure all of the glow plugs and injectors work.
Even though it has far less horsepower then my previous gas trucks, when I am taking off from a normal stop, it just feels more powerful. I got to say, this is my first ford truck and my first diesel, and so far I am very impressed. gonna make sure I keep up on the maintanence too, I definately have some required reading. But thank you guys again for the tips !

 

If you feel you need more HP, you will want to look around for a used turbo kit for like $500. It'll pretty much add 50% more HP safely, especially with you being up in the mountains.
These motors are built like tanks, and just about never die. They just get old and cranky, which is why people complain about them.

 

remember,
Horsepower, is how fast you hit the wall.
Torque, is how far the wall moves after you hit it..

 

I had heard the C6 will just about last forever if maintained properly. Glad to hear some truth to the rumors. And I laughed pretty hard at the horsepower vs torque comment