Contrary to popular belief, the 6.0L Powerstroke is a great engine! Once you work all the bugs out. If you're in the market for a new-to-you 6.0L Powerstroke, here's a list of what to look for when buying. It'll help you determine which bugs need to be worked out. As always, these are the most common issues we see or hear about often, there are others. Do not consider this list all-inclusive. 

Pro Tips:

Do a cold start: Listen for long crank, white smoke, or rough idle (injector/FICM problems).

Do a hot restart: If it cranks forever, suspect high-pressure oil leaks (standpipes, dummy plugs, STC).

Check the degas bottle: Oil sheen or crusty residue means there’s EGR/oil cooler/head cracks/head gasket issues.

Scan data: Compare coolant vs oil temps for oil cooler health (should be less than 15°F apart at highway speeds).

 

1. Head Gaskets & Head Bolts

What to Look For: White smoke, puking coolant from the degas bottle, pressure in the cooling system, overheating. Check for coolant residue in areas you wouldn't expect to see it, when inspecting a truck. That's a telltale sign of failed head gaskets.

Fix: Upgrade to head studs (found HERE) and use MLS head gaskets (found HERE and HERE).

 

2. EGR Cooler Failures

What to Look For: White smoke (coolant steam), unexplained coolant loss, degas bottle bubbling.

Fix: Replace with updated cooler (Bulletproof EGR Cooler can be found HERE and HERE). Also address the root cause. A clogged oil cooler causes most EGR cooler failures. Replace oil cooler, and add a coolant filter kit (found HERE)

 

3. Oil Cooler Clogging

What to Look For: High oil temps vs coolant temps (greater than 15 degrees between teh two is considered a problem), EGR failures, slow turbo spool.

Fix: Replace stock oil cooler with new (found HERE), or some use the Bulletproof Diesel external unit. Flush cooling system, switch to ELC coolant with distilled water. Add a coolant filter kit (found HERE)

 

4. High-Pressure Oil System (HPOP, STC Fitting, Dummy Plugs, Standpipes)

What to Look For: Hard hot starts, no-starts, long crank, ICP low codes.

Fix: 2003–04: Early HPOP failures are common. Replace with updated pump (found HERE).

2005–07: STC fitting on the HPOP cracks. Replace with updated Ford kit (found HERE). Replace standpipes/dummy plugs with updated versions (found HERE, HERE, HERE and HERE).

 

5. Fuel Injection Control Module (FICM)

What to Look For: Rough cold starts, misfires, contribution/balance codes, hard hot starts.

Fix: Test voltage (should hold 48V). If low, repair or replace. New FICM's can be found HERE and HERE

 

6. Injectors

What to Look For: Injector stiction/deposits. Hard cold start, misfires until warm, excessive white smoke at startup.

Fix: Run Optilube Stiction RX (found HERE). This additive and others like it are designed to clean up oil deposits, mainly in the injectors, but in other areas as well. Replace with OEM or quality reman injectors if the additive doesn't help enough. Ensure good, clean oil is used and proper HPOP pressure exists.

 

7. Turbocharger (VGT)

What to Look For: Sticking vanes lead to a laggy spool or no boost. Surging and excessive black smoke are also common.

Fix: Remove and clean turbo vanes. If worn, rebuild or replace. Avoid extended idling periods for prevention. Also, check for wear on the unison ring. This ring controls the vanes and can develop deep wear marks, which hinder its movement.

 

8. Degas Bottle & Cap

What to Look For: Coolant puking out, coolant stains on the degas bottle, hissing from the cap.

Fix: Replace with updated bottle (found HERE) and cap (found HERE). If recurring, suspect head gasket or EGR issue.

 

9. Wiring & Sensors

What to Look For: ICP sensor oil contamination, broken IPR screens, chafed harnesses near valve covers.

Fix: Replace sensors with OEM. Repair/rewrap harnesses with abrasion-resistant loom or replace if necessary (contact us for new harnesses, we can help).

10. Cracked Heads

What to Look For: Fuel in the cooling system is the most common failure. The heads crack around the injectors.

Fix: Replace the heads with new, not reman. The new castings are thicker in the areas where these cracks form.