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Discussion Starter · #1 ·
I am thinking about getting an f-250 and found a couple I like. Almost identical, diesel with a 5-spd, but one has the 6.9l and one has the 7.3l engine. My question are there any big differences in the way these engines preform? I just haven't heard very much info comparing these two engines, and was wondering which to lean tword. Thanks.
 

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Go for the 7.3, much better engine, many of the bugs of a 6.9 were worked out including block porousity, tendancy of the main oil galley near cam to crack, got rid of those prechambers, and a much better designed glowplug system.
 

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PS. Most important is to make sure they have been maintained real well. good for 300,000 if well maintained. But nothing is more disgusting than to have to buy International diesel parts, 1000+ for pistons, 500 plus for a gasket set, etc. bearings are in the 400 range for a full set. (these prices are a few years old, with a full shop discount from NAPA) Machining costs a bunch extra, pure guesswork to time the injector pump without an expensive (700 from snapon)gizmo, and the damn thing weighs 1400 lbs!! I've had 4 ford (international diesel) vans, been there, done that. Still have two laying in back yard needing $$ both of them 6.9. 84 and 83 were the absolute worst years 89 and up had the 7.3 newer you go the better engine, Treat the 5 speeds with care also, they are big $$ for a rebuilt, 1500 to 2000 from major rebuilders, we went through 4 of them on a 450 super duty rollback in four years of general abuse. Brion
 

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The 7.3 IDI still had the prechambers, they left with the Powerstroke, which also displaces 7.3l. If it has a mechanical injector pump, it has the pre-chambers.

The big gotcha with the Ford (navistar/international) diesels is that Ford did not advise owners or even dealers of need for coolant maintainance strongly enough. It was in the fine print, which is not appropriate for something that can cost a whole engine. If neglected the coolant can cavitate and eat into the cylinders. The 6.9w sere the worst offenders, but the 7.3s and even newer Powerstrokes will have trouble if neglected too.

Go to NAPA and get some coolant test strips (PN 106) Test the coolant in any diesel truck you intend to buy. If the Nitrite level is OK, then there is a good chance the previous owner has been maintaining the coolant all along. If the level is zero, pass on that truck.

A 7.3 IDI with a Banks Turbo kit will outrun a stock powerstroke (but not a "bombed" one!) so there is a lot of power potential there. In 94 Ford also sold a Factory turbo IDI.

You will find a lot of info in the archives at http://www.ford-diesel.com/ There is a forum especially for the 6.9 & 7.3 IDI engines.
 

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Actually, I think they sold 3 different 7.3 motors in 94. A non-turbo, a turbo IDI, and a power stroke (turbo Direct Injection). The PSD will say "turbo diesel" on the side and tailgate. There will also be an engine cover that says Direct Injection.
 

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Correct on the three diesel options, but both the IDI-Turbo AND the Powerstroke got the "turbo-diesel" badges...The Powerstroke badges were not seen untill '95. All the '94 powerstrokes went into 5 speeds.
 

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Discussion Starter · #7 ·
I found a couple with the 7.3. One was a 92 and the other a 93. Both 4x4 f250's. What would I be getting as far as axles and t-cases are concerned? It would only have to suffer DD and towing duties for now.
 

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This is oppisite of what everyone is saying but I have a 4x4 f250 with a 6.9 that sat for 7 years and fired right up after the glowplug harness was changed (long story short and pack rat made a nest on top of the engine while it sat) and it fired right up and I haven't had a problem with it. My other truck is a 2wd f350 with a 6.9 and it has almost 1/2 a million miles on it and still running strong. Then there was my Dad's truck 93' f250 7.3 it had major problems it lost compression in 2 cylinders and he is a true believer it preventive maintance. It now has a 6.9 in it too.
Just my .02 cents
 

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The 6.9 and all the 7.3 use the same block. The 6.9 is less prone to the cavitation(sp) of the coolent around the rear cylinder walls. Actully they are the same the 6.9 just didn't have the problems because the cylinder walls are much thicker.

Stay away from 87-88, they tried a new head and they were prone to cracking between the valves. However they can be welded and get another 200k+ out of them. Also if you see a little coolent on the block on the corners of the block, it head gasket is very thin on the corners. This is normal and I haven't seen any that were dripping from there just wet and green.

Either one is fine I have a 86 350 crew cab that has 250k on it. It runs great and starts every time. Also has the ATS on it. You can get more power out of the 6.9 then the power stroke. However the power stroke will out live the 6.9.
 
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