Quick question on the 7.3
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Junior User
Joined: Jan 2009
Posts: 89
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From: Reno, NV
Quick question on the 7.3
Kind of a stupid question... but what year was the first 7.3 IDI available? Was is available on an F-250? I haven't seen any older trucks with the 7.3...
It just seems all the older diesels are 6.9s and I have heard a lot of bad things about them... but the 7.3s are supposed to be good... True? Whats the difference anyway? In fact I recently got a free truck (no title) w/ a 6.9... but it won't start... no fuel to injectors....
It just seems all the older diesels are 6.9s and I have heard a lot of bad things about them... but the 7.3s are supposed to be good... True? Whats the difference anyway? In fact I recently got a free truck (no title) w/ a 6.9... but it won't start... no fuel to injectors....
Postmaster
Joined: Dec 2002
Posts: 3,594
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From: Southern Oregon USA
88 was the first year for the 7.3. The 6.9 and 7.3's were available on F250s and 350s. There are some casting issues on early 6.9 blocks, 83-85ish (near the block heater). The 6.9 has thicker cylinder walls and aren't as prone to cavitation like the 7.3, which has a .110 larger bore. The 6.9 has different rocker arms and a unique glow plug system, (with the exception of the 87 which has both the 7.3's rocker arms and glow plug system).
Jason
Jason
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Joined: Nov 2003
Posts: 21,285
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From: Nutter Fort, WV
The 7.3 is a fine engine, right up till you want to rebuild it.
The mid year 85 to 87 6.9 has a few issues that are easily addressed and is the better of the two in my opinion.
6.9 issues are rocker arms and head bolts.
Head studs take care of the head bolt problem.
87 6.9 engines had 7.3 style rockers which will bolt right on the earlier engines.
7.3 issue, the cylinder wall thickness don't leave any room for boring the block without making cavitation a very pressing problem.
Sleeves in the cylinders is a less than satisfactory solution, so there is no real cure for the 7.3 problem.
So if you asked me, what people are telling you about the two engines is backwards.
The mid year 85 to 87 6.9 has a few issues that are easily addressed and is the better of the two in my opinion.
6.9 issues are rocker arms and head bolts.
Head studs take care of the head bolt problem.
87 6.9 engines had 7.3 style rockers which will bolt right on the earlier engines.
7.3 issue, the cylinder wall thickness don't leave any room for boring the block without making cavitation a very pressing problem.
Sleeves in the cylinders is a less than satisfactory solution, so there is no real cure for the 7.3 problem.
So if you asked me, what people are telling you about the two engines is backwards.
