I tow a large (15,000 lbs.) boat for short distances (about 100 miles) each spring and fall. Untill now I have used a 83 Chev dually with a 454 and an undersift. I am currently looking at a 1988 cube van with a 7.3 diesel. I have always been told that diesels tow better and have better milage, but I am confused after reading this forum it sounds as though the 7.3 (non-turbo) does not have all that much power or great milage. So bottom line will the 7.3 diesel give me the power I got with the 454? Question 2. I hear of the early 7.3s pinholeing. Is this common and how can it be avoided?

 

Very true, the 88-91 7.3s are all ticking time bombs when it comes to pinholeing. All you can do is add lots of corrosion inhibitor to the anti-freeze, hope the last owner did the same, and maybe add a coolant filter.

Now comparing the 7.3 to the 454. Without a turbo that 7.3 will not impress you on any hills, but it should do better on mileage. My 6.9 turbo gets over 11 mpg with a heavy 70's camper and 3500 lbs. of boat in tow, while my Dad's 22' class C motorhome with a 460 gets around 7 (without a boat). We were also pretty evenly matched power wise going up hills. With a van your turbo options aren't as good as a P/U, but they are made.

 

Spectramic,
Thanks for your help. I think I'll pass on this truck and look for a later model 7.3 or find a 6.9. If the engine does pinhole it appears that its no cheap date.
Thanks Again!

 

what exactly is pinholeing? does it happen to the engine or the radiator? i'm also looking into getting a 91 7.3. anything else to watch out for?

 

It's in the engine, anti-freeze eats a small hole through to the inside of the cylinder. Usually the rear one on the driver's side. Makes a good running engine a useless water eating pile of junk. Unless the engine's been replaced I'd stay away from it.

 

Actually, it's called "cavitation" and it's a mechanical reaction, not a chemical one. You can read more about it here:

http://www.arrowheadradiator.com/Cav...ng_Systems.htm

 

Hmm, that link doesn't work.

Well, "cavitation" is nothing more than air getting mixed in with your coolant. And it doesn't matter how it happens, when it does, you're out at least 6 grand!

 

Try this:

http://tinyurl.com/uz7s

 

And they seem to happen at the #7 and #8 cylinders 99% of the time.

 

Thanks for the info on cavitation. I`ve never had a problem with it (that I`m aware of) but now I`m concerned. I will definitely be upgrading my cooling systems.

 

The first pinholed block we ran into back in the 90s, we decided to fix. It was an 88 with around 80K on it. The machine shop bored the cylinder out for a sleeve (driver's side rear). He told us that there was a hole the size of a quarter there when he had it up to size. The customer said he didn't want to run into this again later, so we had all 8 holes sleeved. Turned out none of the others had any holes. It cost $1000 to get the whole block done!

 

I have run a bunch of these engines (10 of our own maby double that of friends) none of them have died due to pinholeing not that it cant happen because it can. As far as power a non-tubo diesel is not going to even aproach the power of a big block. You have a fair amount of torque so it gets along but if you want top end horsepower stick with a big gaser or a turbo setup.

 

Thanks for the info. I believe I will stick with my 454. Its a gas guzzler but it does have the power I need. Better fuel mileage would be nice with a turbo diesel, but I use this truck so seldom that its cheaper to buy gas than spring for the diesel.

 

Umm, where to start?

I think that some people think that every 7.3 liter diesel engine out there is a 'ticking time bomb' just waiting to blow holes into the block.

Well that's just not true. If they were properly maintained (and a LOT of them are) they will be very long lasting engines.

Properly maintained means, 2 1/2 pints of cooling system additive, with every coolant change. And dipping a test strip in the radiator once or twice a yr, then ,MAYBE, adding an ounce of additive.

Think about it. Generally, diesel buyers know what they've got. They anti'd up the extra $3-4000 over the cost of a gasser to get the diesel option. They will, generally, do the proper maintainence, knowing they are protecting their investment.

Dont let peeps scare you away from a 7.3 because of the cavitation issue. If you talk to the previous owner and they've taken care of the maintainence, it could be the last truck you ever have to buy.

Also, DAS (a very well known, and trusted diesel shop) sells a completely rebuilt, drop in, SLEAVED, 7.3 liter engine for around 4K. No too much more than a rebuilt big block gas engine would cost you.

 

They dont say how much to sleve your block.
And $4000 drop in, or $2000 for a shot block sounds like a whole lot more than I can build a big block gas engine for.