Ford Superdutys with Powerstrokes are generally great, robust trucks, but they do have their problems. We’ll break the trucks down into Five categories: Pre-Powerstroke (6.9 and 7.3 IDI Motors), 7.3 Powertroke, 6.0 Powerstroke, 6.4 Powerstroke and 6.7 Powerstroke to discuss items that you should look out for and expect to deal with over time.
Pre-Powerstroke
Though the trucks containing them are tough as nails, the IDI engines lacked real horsepower, so they tend to be pretty boring to drive. The 6.9s had some reliability issues that were pretty much all addressed with the introduction of the 7.3. Both engines use an indirect injection system that suffers more from leaks and air issues than anything else. Here’s what to look for:
- Leaking, cloth-covered return lines and injector return “t’s”. If they are wet, they all need to be replaced. Early trucks have green clamps, later ones use red. If you are attacking this as a DIY, make sure you get the right stuff.
- Leaking Fuel Filters. Happens all the time, either they are loose or the seals go bad and the system sucks air in when parked. Usually a simple replacement cures the problem.
- Injector pumps do wear out, sometimes causing a stalling condition on deceleration.
- Glow plugs. This system just plain stinks. Individual plugs can go bad, but often times it is the controller. They run about $300. For $50, we can install a simple, pushbutton setup that will never fail.
7.3 Powerstroke
Powerstroke 7.3 liter trucks are equipped with a direct injection system, fired by high-pressure oil. Engine oil pressure is converted into up to 4000 psi to fire the injectors. While this system is generally reliable, any oiling issues can mean bad news. Here’s what to look for:
- Fuel floating on the coolant in the expansion bottle. This is an indicator of failed injector sleeves.
- Oil in the engine valley. Many times this oil seeps down the back of the block, between the block and bellhousing and it looks like a leaking rear main seal. It is almost NEVER a rear main seal. We have done one in 10 years. Here’s what it can be:
- Leaking ICP sensor
- Leaking oil filter housing
- Leaking fuel filter housing
- Leaking drain valve assembly
- Leaking turbo pedestal
- Leaking warm up valve
- Leaking oil feed lines
- Leaking fuel hard lines
Most of the above are no big deal and can be dealt with in a day.
- Dusted engine/damaged turbo. Early trucks had notoriously bad air cleaners and would allow dust through. This not only eroded turbo blades but it destroyed rings and dropped compression.
- Transmissions. The e4OD/4r100 transmissions are pretty solid. They do not like to tow heavy loads up hills all the time though. They transmissions suffer from an oiling issue that can starve the converter at extended high rpm/high load. This can be fixed with a proper rebuild that includes some oiling mods.
- Front suspension. Basically any heavy truck, especially a 4×4 diesel with go through ball joints and tie rod ends about every 60-100k, depending on how it is used. Keep track of the health of your front end with regular inspections and keep it in top form to ensure your safety and tire wear.
- A final word on the engine oiling system. 5k-Mile Oil Changes. Clean, regular 15/40 at 5k is better than high-dollar synthetic that can go 15k.
6.0 Powerstroke
Ahh, the infamous/notorious 6.0….. Tons of power, way smoother than the 7.3, nicer all-around trucks. Except for the engine issues. the 6.0 can suffer from many of the same issues as the 7.3, but the addition of a variable geometry turbo and emissions equipment brought all kinds of problems to the table. The good news is that the engine can be made nearly bulletproof and it will easily deliver 300k+ miles with regular maintenance. Here is what you WILL deal with if you own a 6.0:
- Stuck turbo. EGR gasses along with moisture flowing through the turbo will gum up the housing. With EGR/Headgasket issues, the excessive moisture can pit the innards and make the vanes stick. This can cause popping noises, low power and high exhaust temps.
- EGR/Oil cooler combo. Oil coolers clog, this overheats the EGR cooler, the solder comes apart and then your engine starts drinking coolant. Look for white smoke/steam on startup.
- Headgaskets. The bolts used to hold the heads on keep stretching over time. Eventually, under heavy load/boost, the heads lift, compromising the headgasket. If you see white, crusty stuff around the expansion bottle cap, you have bad headgaskets.
- FICM. The Fuel Injection Control Module converts battery voltage to 48 volts to run the injectors. The resistors inside are glued in, and when that cracks out, you loose power, get rough running, etc. Ford will sell you a new one at $1000 or so, or we can fix it better than stock for about half the price.
- HPOP Problems. The high pressure oil system on the 6.0 is even more complex than the 7.3. The high pressure oil pump is the worst/most expensive problem. There is a snap-to-connect fitting on the back of the pump that cracks. this will leave you dead on the road if it goes all at once. It can also seep over time and only show itself when you try to start the truck hot.
- A word to the wise. If you tow, have big tires or run a tuner, you will deal with headgaskets sooner rather than later. BUT, we have done headstuds on 70k mile, 2wd trucks that didn’t tow or run tuners, so you just can’t tell.
- To semi-bulletproof a 6.0, the headgaskets are replaced, with the addition of ARP headstuds. The EGR cooler is replaced with a stainless steel, tig-welded EGR cooler from Bulletproof Diesel that has a lifetime warranty and can’t fail. The Turbo is split and polished to ensure it is not sticking.
6.4 Powerstroke
The 6.4 trucks got a wonderful exterior and interior makeover that makes them a real pleasure to drive. The turning radius was shortened to make them comparable to the Chevy and Dodge trucks. The 6.4 engine is a powerhouse, but it suffers from poor mileage because of its complicated, and troublesome, emissions systems.
- Most issues are cooling system related. The water pumps tend to erode the front cover housing and thus aerate the cooling system. This can cause radiators and EGR coolers to fail.
- Thermostats are also a problematic part, and Ford has updated units that should be installed.
- EGR coolers can be replaced with units from Bulletproof Diesel to solve the failure problem.
- Around 120k miles we have seen a few rocker arm failures that have taken out the engine badly enough that a replacement from Ford was the most cost-effective option.
- Everything is a “Big Job”. The engine bay is incredibly crowded; Twin turbos, two EGR coolers, tons of coolers and electronics make working on a 6.4 a bear. Many wiring harness issues take place under the turbos. This requires the removal of the cab. Most “Big Jobs” start with removing the cab, and this is an expensive proposition.