My current truck is a little worse for ware engine wise might be looking to buy another truck. I got a lead on a '87 f250 6.9L diesel, 4x4, 4 speed, 8ft bed. I dont know the current mileage or any kind of maintenance history on the truck. Guy told me body is a little rough but frame is solid.

I dont know much about diesels and Im curious, is the 6.9L a good dependable engine? Anything I should look out for on this truck?

 

Dependable is a GREAT way to describe it.

The 6.9 and the 7.3 IDI are the same engine. A 7.3 has a larger bore. These engines are mechanically injected, mechanically timed, mechanically everything. The only thing required for the engine to run is fuel and a single 12 volt wire to the fuel shutoff solenoid.

Because they're so simple, they last a long, long time. They can go for about 400,000 or more pretty easily, even without regular maintenance.

Maintenance on the diesels is pretty simple stuff. Cleaning battery contacts, replacing old corroded battery cables, replacing glow plugs (as easy as spark plugs) is the standard stuff. Glow plugs probably need replacing somewhere between every 1 to 4 years. Injectors need replacing around every 100k miles. They are also something that can easily be done yourself. In addition, the return lines dry out over time, so replacing these might be part of your maintenance. You can get a kit from typefour (one of the users here) for under $50 and it's just o-rings and hose and the like, really easy to do.

Easy to maintain, lasts forever.

It's also efficient. My '84 with the 6.9L and 4 speed manual 4x4 gets 16-18 highway mpg, and around 10 in town.

Now what the 6.9L diesel won't do is win races. It's slow. It will pull a heavy trailer uphill, but you're going to be all the way over in the right lane 10 or 15mph below the speedlimit (assuming you're on the highway).

Welcome to our world.

 

I love my 6.9 and it's been a great engine. If you've got the factory water separator, that will probably give you grief at some point, but it's an easy bypass. Always starts dependably in the winter for me. If you do a lot of heavy towing, she'll get you there, but not always the fastest. Just keep up with the maint and it'll treat you great!

I only have one complaint - after 400,000 miles she burns a lot of oil

 

1987 is generally considered the best year for the IDI series. Later 7.3 engines are more likely to have cavitation rot out the block due to the thinner cylinder walls (proper coolant maintenance eliminates the problem). 1987 6.9s should have the improved 7.3 style rocker arms, more reliable (but also more expensive) fuel filter, and solid state glow plug controller with improvements in the engine wiring harness.

All of this goes out the window if the truck was neglected, however. So take a hard look at it as you would any other used truck.

 

Also, the 6.9 was a more solid engine, internal wise, than the 7.3. I'm not sure though. With the right combination of various mods. and parts, you can get power comparable to a 7.3 Stroker. We don't have Strokers, we have Smokers.

 

Look at the mileage of my idi. It's ugly but its still going. Big issue i think would be using the right coolant. I changed mine to fleet charge pre charged. It is a purple color and already has sca in it. You just have to check every other oil change what your sca's are and put more in as needed.

 

Ok, I like what I hear, Im used to not being in the fast lane with my 300-six I pull a car trailer quite a bit when my buddies break their truck, doing contruction, hauling scrap, going to start towing a camper trailer too. I dont tow everyday but I would say every other week or so. Im getting a car for a better DD but I want a truck for a truck for towing and hauling, I dont want something that will keep breaking down on me time after time.

Sounds like a good engine, depending on the mileage, what would be a fair price. I havent seen this one yet or know the mileage or anything, but the guy said 2700 bucks for it, Which is a lot for me right now because Im a poor starving college student who is putting all his money into his truck, food, beer, and guns.

 

That seems a bit on the steep side if you ask me. My dad just bought his 88 from the dealer with 168k and minor cosmetic stuff, everything works and runs amazing, paid $2200 for it and its a Lariat.

 

Well my truck was $2000 list price. Paid the guy $1500 plus partial trade of $200 worth of pork. Altogether, it was $1700. Usually, the cheaper the price, the more work that is needed to get the truck running right.

 

ok, I thought 2700 might be a little steep esp with a rough body

 

You can always offer him less. Depending on how bad the body and interior is, he might be flexible. Don't overlook the engine, suspension, steering, tires and other wear points. Replacing belts, hoses, and other rubber parts adds up quickly. Good tires on one of these trucks will run you just of a grand, so if the tires are new, that is worth something.

 

ok thanks, he did email me back so hopefully Ill go take a look at it tomorrow or the next day and get an idea of what it needs and what its worth. He said he just bought it a month ago from the second owner and its more truck than he needs, so Ill see what I can do.

 

Tires for these trucks can be had for 550 bucks in your case....www.treadwright.com

 

My 6.9 was going strong at over 450k on the motor before I rebuilt it. If you're not to familiar with how diesels like the idi's work than you might be stuck wondering how to go about it at first, but in the end you'll realize how simple they really are. Good luck.

 

It's also good if you have a friend who knows about them too. My brother has a stroker and he knows those 7.3 strokers like the back of his hand, but when it comes to trying to help me with my 6.9, he's lost. The 6.9 is that much different of a beast than a power stroke. Also look at windows and weather striping as they can be pricey.