Hidden Gem Diesel Trucks from Ford, GM and Dodge
For optimum pulling power, fuel economy and durability, the diesel is the engine to have in the ¾-ton and larger truck segment. However, all of that capability comes with a hefty price tag if you’re buying new, which has, in turn, driven prices in the used diesel market skyward in recent years. But what about the trucks no one seems to want, or the models that popular demand seems to have written off? Trust us, there are still hidden gems out there in the diesel world—and they don’t always cost you an arm and a leg. We’ve picked out three prime examples below: a Ford, a GM and a Dodge.
’12-’14 Super Duty
The 1,050 lb-ft 2020 Super Duty might be all the rage right now, but the ’11-’14 trucks also pack the 6.7L Power Stroke (a 400hp, 800 lb-ft version) and have no problem towing or hauling anything you need them to. They make use of the same chassis as the ’08-’10 Super Duty, but the rear 10.5 Sterling axle under the F-250 and single rear wheel F-350 was treated to larger pinion bearings and a selectable locker for 2011. On dually F-350 models as well as the F-450, the Dana 80 was available out back. In addition to getting the 6.7L Power Stroke, you get the stout 6R140 TorqShift: the six-speed automatic transmission that’s even tougher than the 5R110W that preceded it.
Skip the 2011 If You Can
You may be wondering why we don’t recommend the ’11 model 6.7L Power Stroke. It’s because some of them hold a potentially catastrophic secret. Particularly on early 6.7L mills, cracked valves could break apart and drop in-cylinder. By the ’12 model year, Ford seemed to have addressed and solved this somewhat rare (yet no less worrisome) cylinder head issue.
Don’t Fear the GT32 SST
This is one of the primary reasons many soon-to-be diesel owners avoid the early 6.7L Power Stroke: the Garrett GT32 SST variable geometry turbocharger. It’s prone to overspeed failure, but that typically only occurs when aftermarket programming is involved and the charger sees excessive boost. This can be controlled (in tuning software) by limiting peak boost to less than 30 psi and being less aggressive with the turbo’s vane positioning. Better yet, the aftermarket makes retrofit kits that allow you to install the more reliable, ’15-’19 style turbocharger in place of the GT32 SST. Definitely don’t let this turbo scare you out of buying a ’12-’14 Super Duty.
’98.5-’02 Dodge Ram 2500 or 3500
It may have been the loudest version of the 5.9L ever produced, but the 24-valve Cummins ISB is an absolute hoss of an engine. It was available with the NV4500 manual, the NV5600 manual in high output versions (beginning in ‘01) and the 47RE automatic, though we’d stick with the hand-shaker (Chrysler’s automatics have never held up very well behind the Cummins). The 24-valve engine gets a bad rap for its Bosch VP44, an electronic rotary style injection pump that is notorious for sudden failure. However, if you address the primary source of the VP44’s problem, the lift pump, the VP44 isn’t really a worry at all. You’ll have to head south, west or a little of both to find a rust-free ’98.5-’02 Dodge, but they’re out there.
Add A Quality Lift Pump
The VP44 injection pump (shown above) is the biggest worry for most potential 24-valve Cummins buyers. Reliant on consistent fuel pressure and volume, the VP44 often dies (or becomes damaged) when the factory lift pump goes south or fails to provide more than 5-psi of fuel supply pressure. Therefore the first thing you should do is scrap the factory lift pump (engine mounted or in-tank) in favor of a chassis-mounted electric replacement. Fuelab, FASS and AirDog all offer pumps as well as complete tank-to-engine fuel systems and components to make this happen.
A Fuel Pressure Gauge Is A Necessity
Because the VP44’s life depends on fuel supply pressure, the added peace of mind an in-cab fuel pressure gauge offers is invaluable. On top of that, some aftermarket companies even offer low-pressure alarms to make sure you’re tipped off any time fuel pressure drops below a pre-set amount. Ideally, the VP44 needs to see 12-15 psi of fuel pressure at all times (idle, cruising or under load) to live its best life. When you combine a fuel pressure supply gauge with a quality lift pump and perform regular maintenance (i.e. fuel filter changes and buy good, clean fuel), there is no reason why a VP44 won’t last indefinitely.
’01-’04 Chevrolet Silverado/GMC Sierra 2500 or 3500 HD
Injector issues and the extensive labor required to fix them scares a lot of prospective Duramax owners away from the LB7. Though many of these engines have already been treated to updated and higher-quality replacement injectors at this point, some have not. As such, the injector hysteria persists and potential buyers go elsewhere. It’s a shame because they are great entry-level diesel trucks, complete with the beefy AAM 1150 rear axle, usually equipped with the Allison 1000 automatic transmission and pack 300 hp and 520 lb-ft of torque bone-stock. Now, finding one with mint rockers is a whole other animal. Check the classifieds or auto auction in Tampa…
The Injectors Might Not Go 500K, But The Rotating Assembly Will
Aside from the factory injector issues (which is essentially the injector not being able to mechanically turn itself off and showing itself in the form of smoke at idle, excessive injector balance rates, engine knocking and fuel in the crankcase), the LB7 is very reliable. It was exempt from emissions control devices such as EGR (aside from ’02-’04 California models), was produced before the time of DPF’s and DEF and can easily go 500,000 miles if properly cared for. Aggressively-tuned engines might toast a head gasket around the 200,000-mile mark, but reconditioned heads, new gaskets and ARP studs solve that problem from ever happening again. If you find yourself the owner of an LB7 in need of injectors, start with the latest updated versions from Bosch and never look back.
Every generation of the Duramax came with its own unique issue. Find out which one you need to address right here.