Hey guys I just recently got a 1985 F250 4x4 4spd with the 6.9L engine in it at 250k miles. Everything seems to be working well with the engine right now. I want to make sure it stays that way. Is there anything I should change with it to make sure it lasts? I thought about changing the glow plugs since it seems to start up a little slow. Someone mentioned to me at Oreily the other day changing the injector o rings. Does anyone have a list of the most common issues and what I need to do to prevent them? Thanks so much guys!

 

Air intrusion in the fuel system seems to be the most common problem with these old trucks. That would be the o-rings ORileys was talking about. If the previous owner used junk glow plugs they won't last long. Use Motorcraft ZD1 plugs in the 6.9.

 

Personally I would not mess with the return lines if they are working. When you do make sure to get the viton orings. When you replace the glow plugs, try not to disturb the return lines, or you may have to replace them.

 

Good preventative maintenance would be a full tune up if it hasn't been done in the past 150k.

Injectors and IP, and that old beast will feel like a completely different rig!

 

what is the IP? can havoline and oil changing shops do a tune up or do I need to go to a specific diesel shop?

 

IP - Injector Pump.

If you got some tools and abit of mechanical knowledge, you can actually do it your self. It's pretty easy to work on these.

But if you can't do it, take it a good recognized diesel place.

 

Check the coolant for SCAs and replace it if it is old or has no SCA reading. Search the forum as there is plenty of info on SCAs and how to properly flush the coolant system.

Oil change, filters, front and rear diff service, check the brakes, inflate the tires to the proper PSI, always run a good fuel additive that adds lubricity for the IP. I use Diesel Kleen.

 

Well I have only had the truck for about 2 weeks so I havent hurt anything yet by not knowing about SCA's but now I do. Unless the PO did something to it. I did check it for blow by which a friend told me about and it didnt smoke so I think its ok.

I will check the SCA levels when I get back and start adding a fuel additive when I get back home to the truck. What should be changed with the injector pump?

Also sometime the truck is a little slow starting up for the first time during the day.. I am just guessing with my newb knowledge that it needs new glow plugs. I am guessing that because after the I stall the truck (which I always do since I am also just now learning to drive a stick hah) it starts right back up and I dont even need to wait on the glow plugs to warm up in anyway

 

you can get an SCA test kit at any decent part store., they till be little test strips you dip in the coolent and check the color against the code on the bottle.
as was mentioned a fuel system service is due about every 150-175k. that would be replaceing the ip injectors, and return caps and lines. youll need to go to a mechanic thats fimiliar with diesels if you dont feal comfortable doing it yourself. however if the truck runs good, starts decent, and dosent mis fire or smoke real bad you may be ok, at least for now. powerservice fuel additive will be your friend, use it
other than that regular oil changes, and make sure you get religious about checking oil. use only zd9 glow plugs as was mentioned, change your fuel filter with a good filter once a year or so, depending on the miles you drive, and dont forget to periodicaly drain the water from the fuel filter, theres a little know on the bottom of the filter bowl to drain it. keep your batteries in good shape and the cables clean. other than that do your regular maintenance like you would any other truck

 

regarding posts about SCAs, thats only an issue on the 7.3 with its thin cylinder walls, and is really not important on a 6.9, but keeping it up won't hurt anything
when you mention slow starting for the first time in the day, does this mean 10 seconds of cranking or 2 minutes? if its 10 seconds, maybe you were never instructed to turn the key on, wait for the glow plugs (wait to start light), then crank on it. if you're talking more like 2 minutes of cranking, you have air getting into your fuel lines through the return line system, repairs are simple, but continuing how it is will cost you in batteries and starters.

 

SCA's are important on all diesel engines, cat cummins and detroit all have problems, the 6.9 is just a little more metal to go through than the 7.3, but it still can.

 

No I am aware that it needs to sit and let the glow plugs warm up. I wait until the light goes off and I dont hear the clicking anymore. Sometimes I will let it go through the process twice before trying to turn it over and it takes like 10 or so seconds of cranking. Any ideas?

 

You need to start it immediately after the light goes out, they will click on and off for a few seconds after the motor is started, until the cylinders get some heat in them.

 

So I dont need to wait for the clicking to stop? I should just start literally as soon as the light goes out clicking or not?

 

Try depressing the throttle 1/2-3/4 of the way down while you are cranking it. That will let more fuel into the engine and give it more to burn. Don't let it rev up too much once it starts. AKA, don't keep your foot on the pedal once she fires off.