Ford 7.3 - any reason to not get one?

b. rock

Member
Getting close to sealing a deal on a van. It has the venerable 7.3, highly regarded for sure, but also rather old school. About 175k miles on it. In this day and age with these engines being 20+ years old, is there any particular reason to avoid them? I really don't mind regular PM or the occasional parts swap on an engine if it's going to last, and the lack of EGR or DEF is a plus for longevity. The trans is a slight concern but it's cheaper than bulletproofing a 6.0. It doesn't seem like there are too many things that can fail on a 7.3 and leave it dead on the side of the trail, and the aftermarket support seems pretty robust as well (unlike the 2V V8s + V10s). Am I missing anything?

Edit: it's a 1998, if that matters (doesn't seem like the van engines changed as much as the truck engines)
 
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tatanka48

Active member
with anything that age you will encounter the usual rubber part failures along with stuff like starters waterpumps and alternators that get tired

all part of the used vehicle scenario

the 7.3 as do all big D's relies on clean air and clean fuel so filters need attention

sure would be nice if you were offered maintenance records in the deal

the transmissions live about 150k - 200k

diff's live even longer(350k on mine currently)

the transmission a/o oil coolers did have issues about 300k and you will recognize the issue by the color of the coolant in the radiator

front hubs(4x4) can begin to make noise anywhere after about 150k and they are complete assemblies that simpy get swapped out

fuel tank filter/lift pump will last over 300k± if you provide relatively clean fuel from reliable sources

if your $$ and the asking price are within your comfort level it sounds like a simple decision

BONNE CHANCE

T
 

TomsBeast

Member
Hmmm.... any reason NOT to get one?

They stopped building it in 2003 I think, although not a problem today the aftermarket is moving away from supporting the 7.3. Your Ford dealer's service department might stop supporting it as well.


They are noisy inside the cab, so if that bothers you...
 

b. rock

Member
Eh, my TDI vanagon rattles pretty good as it is and doesn't bother me or the wife. Granted the 7.3 is almost 4x the size of the 1.9 TDI engine and underneath the cab instead of behind it. Duly noted.

Not worried about dealer support, I haven't had a car worked on by a dealer outside of warranty work + recalls.

Maybe I'm just used to the near zero state side support for the Toyota 1FZ-FE in the 80 series, but the aftermarket for the 7.3 seems fairly robust - alternate fueling systems, upgraded turbos, injectors, torque converters, whole transmissions, etc. I guess that could all die off potentially.
 

TomsBeast

Member
You're already a Diesel guy, and a fan of older VW's and TDI's, so you know what all is involved with cost and maintenance items. (my '95 SMB has the 7.3, my daily donkey is a VW TDI, I also do my own work for the most part).

There's several things that need addressing on a high mileage 7.3, if the previous owner can't prove he's taken care of, I'd plan to get on them right away.

-Fuel system, the fuel filter bowl has a drain valve that's prone to leaking from it's o-rings. Sediment builds up in the bottom of the assembly
-Oil cooler seals get brittle and are known to leak with age, cross contaminating oil into the cooling system. Oil floating floating in the degas bottle is the giveaway.
-Various oil leaks into the valley between the heads. There's got to be 25 fuel and oil seal leak paths that when they fail, accumulate in the valley. The rear of the valley has a drain hole, that leads to the the space between the trans and block. After various leaks put about 1/2qt intot he valley, then it dribbles out the drain hole, and makes it look like it's got a rear main seal leak, when it doesn't. The valley is crowded with stuff, any one of the connections leaking can be tough to diagnose.
-Clean oil is your injector's best friend. High pressure oil from the HPOP acts as a hydraulic intensifier, give the incoming fuel a kick in the ass, boosting fuel pressure to 700psi at injection time. That pump and it's fittings can leak.
-They say replacing abused injectors on a 7.3 is the most expensive maintenance item on that engine. On the van, they are even harder (more hours) to change out. Injectors alone are about $175ea x 8, plus brass cups, valve cover gaskets with integral injector wiring harnesses.

Carry a spare crank/cam position sensor, they are cheap, easy to swap out if one craps out on you.
 

b. rock

Member
Yeah I had read about the HEUI system. Pretty neat really, definitely creative.

The rest sounds like a normal 20 year old engine - hoses, o-rings, fluid leaks, etc. Just crammed into the doghouse of a van is the big difference. Nothing you've listed seems to entail lifting the cab off of the frame, which is a huge plus. I'm of the type that if I got one of the valley leaks, I'd probably do most anything that was in there at the same time just to be done with it since it'd be pain to get in there. Not a big deal if it can be planned, and the leaks aren't catastrophic preventing use until then. I'll be googling the crank + cam PS's - used to carry one of those for the old 5 cyl Audis...

It all sounds about as expected - keep an eye on things and repair/replace as necessary and enjoy, with no major achilles heel that's always just around the corner (looking at you, 6.0). I was just getting a pinch of cold feet since this will be the most expensive vehicle I've purchased to date. However the more modern options all lack something - either less robust, no/limited 4x4 conversion options, more complex (esp modern diesels w/ DEF), or 6 figure price tags, so this is where I landed.
 

b. rock

Member
Side note, any sound comparison to a '98 Ram with the 5.9 Cummins? The father in law has one and I can tell when they're about a block away. It's seriously louder than any neighborhood tow truck, garbage truck, delivery truck, etc.
 

eblau

Adventurer
they are cool, get one

I've had both a 5.9 12v and both IDI 7.3 and PS... 5.9 seemed a little louder than the 7.3.... both sound great with a more free flowing exhaust, lots of turbo noise
 

Grenadiers

Adventurer
We replaced the tranny on our 01 F350 at 200,000 miles; in the middle of Missouri. Thankfully there was a Ford dealer in the area. They have a HD version of that tranny now, which we installed. Replaced the unit bearings up front and pads around that time too, 600 bucks in parts I did it myself. Glow plugs go out as well. And the relay. If you can access the turbo, good to check the blades for cracks. See if there are any service records.
 

gmtech

Observer
yea 7.3 might be hair more quiet then 5.9 stock wise. 5.9 with exhaust always reminds be of a semi!.
no reason not to get it other than slow and makes a lot of noise.
 

b. rock

Member
yea 7.3 might be hair more quiet then 5.9 stock wise. 5.9 with exhaust always reminds be of a semi!.
no reason not to get it other than slow and makes a lot of noise.
Ah, good topic. I've heard mixed results on the 'slow' portion. Surely with ~500 ft/lbs they pull their own weight around decently? All it needs to do is climb I70 at 65 mph and I'll be happy. There's no VGT or anything fancy, but I'd wager that a billet wheel and a tune would wake it right up?

My current TDI only has about 90 hp and 150 ft/lbs, and it feels like a lot more, but that's in a much lighter ~4500lb vehicle.
 

TomsBeast

Member
The rest sounds like a normal 20 year old engine - hoses, o-rings, fluid leaks, etc. Just crammed into the doghouse of a van is the big difference. Nothing you've listed seems to entail lifting the cab off of the frame, which is a huge plus. I'm of the type that if I got one of the valley leaks, I'd probably do most anything that was in there at the same time just to be done with it since it'd be pain to get in there. Not a big deal if it can be planned, and the leaks aren't catastrophic preventing use until then. I'll be googling the crank + cam PS's - used to carry one of those for the old 5 cyl Audis...

It all sounds about as expected - keep an eye on things and repair/replace as necessary and enjoy, with no major achilles heel that's always just around the corner (looking at you, 6.0). I was just getting a pinch of cold feet since this will be the most expensive vehicle I've purchased to date. However the more modern options all lack something - either less robust, no/limited 4x4 conversion options, more complex (esp modern diesels w/ DEF), or 6 figure price tags, so this is where I landed.


That's about right. It's no 6.0, no EGR cooler to $hit the bed, no 'too few' head studs, etc.

I'm doing the valley leak abatement on my 1995 7.3 right now, just as you describe, all of the fuel filter housing seals, fuel line seals, fuel lines, and a few other things at the same time.

Different than the truck, on the van you get valley access from inside the van, remove the up-pipes (prone to developing leaks, and robbing the turbo of required driving force) then remove the turbo (who's exhaust back pressure valve (EBPV) is prone to leaking oil into the valley), to gain access to the valley, filter housing, fuel lines, the HPOP.

With what I know now, at time of purchase, I'd remove the doghouse (check it for sealing, clamps, if it has gaps, inside the cab will be significantly louder) and do a 'dip stick' test into the valley, with a paint stir stick or something, to see if the valley is full of oil. and or fuel.

Good luck!
 

wjeeper

Explorer
Let me preface this with I have no real world experience with the 7.3..........but here in Utah diesels are so much more spendy than a gasser! I was looking for a Duramax van (unicorn) and figured that I could buy a gasser, lift it, get new tires and build out the interior and be cheaper than a stock diesel.

Did international cast the 7.3 blocks out of solid gold?

Any reason not to? How do you plan to use the van? Do you tow? Whats your projected built out weight? For me the $$ out weighed the cool factor of a diesel.
 
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