Ford 7.3 idi diesel?

Are there any major issues with these engines? I saw a couple trucks with them for sale for a decent price and I am tempted to look at one.  I remember the 6.9 and 7.3 diesels used to be pretty common but I rarely see them on the road anymore.  

Cockroaches and 7.3s will take over the earth after the apocalypse 

Truck version of a W123 Mercedes would be exactly what I'm looking for.

See if they kept up with coolant system maintenance, otherwise check the usual stuff. Rebuilt engines will costs more than the entire truck is worth by 2-3 times.

Don't buy one with mystery crud in the bottom of the fuel tank that you don't find out about until later.

I know, I know. Not useful, and unlikely to be a common problem. Just bitter about unrelenting problems with what had otherwise been a pretty nifty truck (that got better mileage than I'd ever have expected from a 3/4 ton 4x4)...

81cpcamaro said:

See if they kept up with coolant system maintenance, otherwise check the usual stuff. Rebuilt engines will costs more than the entire truck is worth by 2-3 times.

It looks like $3-4K, cheaper than a Mercedes diesel at least.

I have a buddy that runs them exclusively in his plumbing biz.  His guys can't kill them, economy is decent (we are talking non turbo, pre Powerstroke?) Cheap to buy and nobody ever gets a ticket because the 0 to 60 is like 7 minutes 

It's the diesel version of the 300 straight 6 imo

Justjim75 said:

I have a buddy that runs them exclusively in his plumbing biz.  His guys can't kill them, economy is decent (we are talking non turbo, pre Powerstroke?) Cheap to buy and nobody ever gets a ticket because the 0 to 60 is like 7 minutes 

The ad that made me ask this question was a 93 I think so that was was turbo, but yeah any of the pre-Powerstroke ones.

I believe the IDI diesels were purely mechanical where the 7.3 powerstroke was computer controlled. Seeing the condition of some of my 7.3's wiring at 25 years old, I think the mechanical system is a huge plus. 
 

edit: mine is a van which runs hotter under hood temps. 

Justjim75 said:

It's the diesel version of the 300 straight 6 imo

That's an interesting comparison to me because in the early '80s I worked for a company that had a fleet 15 passenger busses built on stretched E350 Econlines that were powered by 300 sixes and the 6.9L international engines.  Both of them were really reliable, lasting several hundred thousand miles with nothing but routine maintenance.  

Neither of them liked it if you put the wrong fuel in them but that's not the engines fault.

The 6.9s would weep coolant out of the back of the head gaskets and at first we would change the head gaskets to fix it.  After a while though we would just hose them down with brake clean when we changed the oil and just before DOT inspection. We had some glow plug issues early on before we figured out what the change interval should be but once we had some data to know when to change them preemptively that was no longer a problem.

I worked at a Ford dealership in the late '80s when the 7.3l engines came out and I don't think I ever had to do anything to the engine on one of those.

had a 6.9 idi for a long time in an 84 f250. Other than the glow plugs, that thing just worked. 

I had a 6.9L in an 86 F350 for a while.  I bought it from my friend who had put 300k on it towing a monster fifth wheel.  Not sure how heavy it was, but it was 40' long and had three axles, so probably somewhere north of 14,000.

It was slow and wouldn't die.  I bought a used Banks turbo kit for it but before I could put it on I ended up getting offered a ridiculous sum for the truck and kit so I sold it as a package.

Many of those older diesels just ran.  6.2L GM, 6.9 and 7.3 IDI, early mechanical Cummins.... they just do everything (except speed) very well and for a long time.

Even the much-hated 5.7L Olds diesel worked well once you fixed the head bolts

In reply to APEowner :

As in, slow and dead nuts reliable?

In reply to Justjim75 :

Yeah, they're VERY slow - but fix on the side of the road with a rubberband and some tape from what I understand. A lot of the cheaper tow trucks have them in it so I did a bunch of research before I got a PSD truck instead, they're just dandy for getting around in-town and not in a hurry, but apparently you're going to spend a lot of time accelerating if you took it on the interstate even with the crazy short rear gears. Even my 7.3PSD fully loaded isn't exactly a rocketship so I can't imagine how slowly those must get up to speed.

What's OP looking to do with this truck? 

I once had an E350 extended with a 7.3 IDI and E40D.  That thing would idle down the road.  With dual tanks it went forever.  I think the only issue I had was a pinhole leak in the oil pan.  I noticed it doing an oil change the day I was leaving for road america - I JB welded it and forgot about it for the next few years.  Solid.

Justjim75 said:

In reply to APEowner :

As in, slow and dead nuts reliable?

Yup.

I've owned quite a few.  Terribly slow NA, but a turbo one will just about run with a stock 7.3 powerstroke.

Put probably 100k mi on a '85 6.9 non turbo with a C6.  I pulled it out of a field for $200, got it running and daily drove it for years.  Mid teens for mileage and just did work.  Wish I still had it.

I had to put a low pressure fuel pump in it, and eventually an injection pump.  Injector return lines are a common maintenance item but easy to fix.  Glow plug controllers are problematic, but it is very easy and recommended to just convert them to a manual push button.  Other than that they just run.

Here's a pic of it about 1000 mi into dragging home a bad idea.  Expect 20mph or less over moderate grades.  I took it to Colorado over eisenhouer pass and I am pretty sure if I stopped i would have not been able to get it moving again

accordionfolder said:

What's OP looking to do with this truck? 

Mostly for hauling stuff that any truck could probably do (car parts, lumber, etc) and to use for camping/light off road driving.  Eventually finding a pop up camper would be nice too.  It seemed to be a good enough vehicle for this:

I need to drive one and see if I like them and could deal with how slow they are, but it seems like an interesting potential option instead of a worn out early 2000s SUV or pickup for the same price, or a new base model ranger that would be about at the limit of my budget.  No emissions testing and dealing with failing emissions equipment, simple repairs, and minimal electronics and ticking time bomb maintenance issues makes it seem appealing.  They do seem quite expensive though, rough 4wd ones are selling fast at $6-7K in my area, or $5-6k for a 2wd 6.9. 

I have a 1991 F250 4x4 diesel.  Non turbo.  A turbo really woke these engines up.  Without a turbo the engine does not make enough power to hurt itself.  Which is why they run and run and run.

Other than standard maintenance the best upgrade you can do is replace the huge, heavy starter with a gear reduction starter that is available online.  And these trucks are getting old enough that parts are becoming available again.  Today I ordered a left tailgate latch online (NO, not from A*azon or Epay. ) which has been discontinued from Ford.

Like a lot of vehicles, rust is the killer here.  I have over time replaced all the hard brake lines with the exception of the hard brake line that goes to the right front.  Both fuel tanks have rusted out.  The rear one was replaced first and a few years later the front tank started leaking.  On that one I took the easy way out and stopped using it.   Sad, I know.  

There are other things, but it is an old truck.

Scott