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Posted: 12/21/2011 5:11:51 PM EDT
Link Posted: 12/21/2011 6:55:10 PM EDT
We had about 6, 6.2 liter diesel trucks that ran hundreds of thousands of miles with almost no issues. 2wd, 5 speed. When the 6.5s came out we bought two that had continuous engine troubles. They use the 6.5 in the humvees, so they must have worked the bugs out of them. The 6.5s & 6.2s are seriously underpowered, but may be fine for u in 4x4 since you'd have low range.
Link Posted: 12/21/2011 7:17:55 PM EDT
[Last Edit: 12/21/2011 7:19:52 PM EDT by Justin-Kase]
There can be issues with the diesel injector pump, but at that age it's probably been replaced.
I went through two pumps on a '95 pickup in less than 70k miles.
Overall it is a reliable engine. The are low on horsepower but make good torque.
If you want to spend the money there are plenty of upgrades to increase power.

I would be concerned about parts availability in South America. Gasoline engines were much more common in these trucks up here at least, so parts for the 6.5 are not as common. that might be something to consider.

Also depending on fuel prices and availability. Diesel is now more than gas here and the 6.5 really doesn't get that much better mileage so again depending on local price it might be more expensive to drive.
Link Posted: 12/22/2011 6:20:00 AM EDT
The 6.5s from '96 to '00 or so had sporadic problems with cracked blocks. My dad had a '98 suburban with a 6.5 TD when I was growing up. It was definitely not a good puller and would run into heat problems towing a small airstream or boat on grades.

It was sold and replaced with an Excursion 7.3L Powerstroke TD. No comparison. That 7.3 was an animal.
Link Posted: 12/22/2011 9:54:14 AM EDT
I used to work on these quite a bit at a shop out of college. They are pretty problematic. Especially the Glow Plugs. They fail regularly and are damn near impossible to get out of the block without breaking them off. They become very brittle, and when they do break off, your in for a world of hurt. I reccoment the Isuzu Duramax, IE 6.6 in GM trucks. The 7.3 Fords is good too. But they tend to go through injectors and pumps around 100k. Just my .02
Link Posted: 12/22/2011 10:45:57 AM EDT
Link Posted: 12/22/2011 5:22:12 PM EDT
I had a 95 2 dr Tahoe with the 6.5L. It had already had the injector pump replaced and other than a vacuum pump I never had any problems with it. I passed it on to my younger brother and he drove it to 180k before we sold it to a friend of mine who drove it over 200k. It pulled a lawn mowing trailer for 2 years and my 21' Crownline boat every weekend to the lake. It wasn't a power monster by any means but I liked it better than my friends gas 350 powered Tahoes. If I remember it got high teens for mileage.

FWIW I also owned a 6.2 diesel Blazer before the Tahoe. Lots of people trash the old GM diesels. The truth is they aren't a Cummins, Powerstroke or Duramax but they are reliable and get good mileage.

Link Posted: 12/24/2011 1:37:48 PM EDT
All true.
The 6.5 is pretty tough, but the injector pumps are a weak link. (and expensive). Auto trans will have an auto trans life span. They are underpowered.
Having said that, the 6.6 (duramax) is all power, but no durability. (don't expect over 200k)
My 7.3 is a beast. A llittle more power than the 6.5. 400k mile and still my daily driver.

Was never a Ford guy before this having this van.
Link Posted: 12/28/2011 6:34:37 PM EDT
Probably in too late for the OP since he already said he'd pass, but there are a few things that can be done to increase the reliability of these engines.

First, remove the plastic "Turbo Power" cover if it's still on the engine. They hold heat in, which is what typically kills the PMDs (Pump Mounted Driver) on these things. Dead PMDs are the number one reliability issue with the 6.5l.

Then, get an extension cable and move the PMD off the injector pump to a spot with a little more airflow. Make sure there's good contact with the heat sink.

Or, for the ultimate in reliability, ditch the DS4 electronic injector pump and install a DB2 mechanical pump calibrated for the same power level (190hp @ 3300 IIRC.) This does away with all the engine electronics, and only requires an ignition-hot wire to energize the fuel shutoff solenoid. You'll need an 85-93 glow plug controller (or spring-loaded manual switch), because 94-up engines use the PCM to control the glow plugs. I'd go with a switch that energizes a relay, since the 85-93 controllers don't always stay on long enough to heat the AC60G glow plugs in cold weather. I'm guessing it has an automatic, which will be looking for signals from different engine sensors, so get a standalone computer for the tranny. Or you could swap in a manual and eliminate that potential problem as well. The automatics are pretty reliable, though, just avoid rocking back & forth to get unstuck.

An advantage of swapping to a mechanical injector pump is you'll have the ability to use more fuels. The electronic pump uses an optical sensor inside the pump to help with timing, and fuel opacity can mess it up or keep it from working. Fuels you can run in a mechanical pump include diesel, Jet-A, kerosene, home heating oil (the dye would screw up the optical sensor on the electronic pumps), waste engine oil mixed with diesel, or unleaded gasoline in a pinch (also bad for optical sensors), waste vegetable oil, etc.

Glow plugs haven't been an issue since the early 90s when the AC11G plugs appeared. Current plugs are AC60G and DO NOT burn out. I've had them lit up for hours at a time while testing for possible use in my old 7.3l Navistar diesel (not the T444E/PowerStroke) and there was no swelling or deformation of the tip. Even back in the old days when the AC9Gs were used, they rarely burned out when the first generation (82-84) glow plug controller was working properly. Problem was, it was somewhat common for them to get stuck "on" due to one of the 4 switches inside welding itself closed, which obviously led to the glow plugs being powered as well. It doesn't take much more than 30 seconds or so of continuous power for an AC9G to swell and burn out. They'll last thousands of 8-12 second cycles, though.

The 6.2l and 6.5l are simple and pretty durable & reliable. One of their biggest advantages is you don't have to drive them any differently than you would a gasoline engine. They have their quirks, but what doesn't? They're not medium truck engines like the Cummins or Navistars, but will still last a long time with minimal downtime if proper care is taken and you don't hot-rod them.

Link Posted: 1/3/2012 11:32:17 PM EDT
I spent years driving a military HMMWV with the 6.2. Only recurring issues the glow plugs burning out. At some point the glow plug controler was updated and rarely had issues after. I drove one load over 9000lbs in Desert Storm and got 14 mpg. To slow acceleration is due to the tranny upshifting rapdidly to keep the engine in the torque range. I overcame this by manually shifting, allowing me to keep it in each gear longer. The military HMMWV shifter acts like a ratchet shifter when shifted this way.

If it's possible to get the tranny shift points recalibrated, you will see faster acceleration.
Link Posted: 1/5/2012 8:54:26 AM EDT
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