Symptoms · 6.0 Power Stroke (2003-2007)

6.0 Power Stroke (2003-2007): losing coolant

5 documented failures on this engine list this among their signs. They are ordered from the most widespread down. Each one shows the signs in its record's own words, how to tell it from the others, the usual fix and any recall or bulletin.

EGR cooler failure Near-universal · 37 complaints · 3 recall/bulletins
Engine oil cooler clogging / failure Near-universal · 25 complaints · 3 recall/bulletins
Head gasket failure / cylinder head lift Very common · 21 complaints · 2 recall/bulletins
Degas bottle / coolant reservoir crack, or failed cap Common · 4 recall/bulletins
Water pump failure Common

Not sure which engine you have, or want the recalls for your exact truck? Check your VIN: it names the engine and lists the campaigns for that model year. Whether a recall is still open on your VIN: nhtsa.gov/recalls.

1 EGR cooler failure

verified How widespread: Near-universal 37 NHTSA owner complaints match it, out of 336 checked

How it shows up

coolant loss with no visible external leak
bubbles or pressure build-up in the degas bottle
overheating; low-coolant warning

Its other signs

white, sweet-smelling smoke from the exhaust on acceleration or at idle
rough running or misfire if coolant enters a cylinder

How to tell it apart

chemical combustion-gas test on the coolant (block test)
pressurise the cooling system and look for coolant entering the intake or exhaust
borescope the intake / EGR passages

Usual fix

install an upgraded EGR cooler; ALWAYS replace or verify the oil cooler at the same time or it will fail again

Recalls and bulletins

TSB 09-15-6 Voluntary Emission Recall 06E17 TSB 05-4-17

Root cause, parts and sources →

2 Engine oil cooler clogging / failure

verified How widespread: Near-universal 25 NHTSA owner complaints match it, out of 336 checked

How it shows up

coolant in the oil or oil in the coolant (internal cooler leak)

Its other signs

engine oil temperature (EOT) runs well hotter than engine coolant temperature (ECT) under load
repeated EGR cooler failures
overheating during towing or grades
reduced heater output

How to tell it apart

with a scan tool, compare EOT and ECT at steady highway load: a delta above roughly 15 F indicates restriction (SME to confirm exact threshold)
check for oil/coolant cross-contamination
inspect coolant for the sludge that causes it

Usual fix

replace the oil cooler; thoroughly flush the cooling system at the same time

Recalls and bulletins

TSB 20228 SB-20720 TSB 04-18-6

Root cause, parts and sources →

3 Head gasket failure / cylinder head lift

verified How widespread: Very common 21 NHTSA owner complaints match it, out of 336 checked

How it shows up

white smoke and coolant loss
immediate pressurisation / bubbling in the degas bottle on start-up or under load
coolant overflow, overheating, sweet smell
misfire; coolant in a cylinder on borescope

Its other signs

overheats and then stalls, and will not restart until cooled

How to tell it apart

combustion leak (block) test confirming exhaust gas in the coolant
cooling system pressure test
running compression / cylinder leak-down

Usual fix

ARP head studs plus new head gaskets; machine-shop check of head and deck flatness; the gasket MUST match the dowel size (18mm: Ford 4C3Z-6051-EB, engines built before 2006-01-16; 20mm: Ford 6C3Z-6051-AA, engines built 2006-01-16 and newer - Ford catalog gasket application rows). Confirm dowel size by build date, measurement, or head casting number (18mm: 1843080C1/C2/C3; 20mm: 1870389C1); a step dowel (Ford 6C3Z-6B041-B) adapts 20mm heads to an 18mm block

Recalls and bulletins

TSB 08-23-8 TSB 04-17-4

Root cause, parts and sources →

4 Degas bottle / coolant reservoir crack, or failed cap

verified How widespread: Common

How it shows up

coolant seepage and staining around the reservoir at the top rear of the engine
slow, unexplained coolant loss; coolant smell
coolant overflow from the degas bottle

Its other signs

cap not holding pressure; false overheating or coolant-push symptoms that mimic head gasket / EGR cooler failure

How to tell it apart

pressure-test the cap and the bottle
inspect for hairline cracks and coolant staining
rule this out before diagnosing head gasket or EGR cooler failure

Usual fix

replace the degas bottle and cap (inexpensive); do it during any other cooling-system work

Recalls and bulletins

TSB 05-26-23 CSP 05B32 TSB 05-17-13 TSB 05-24-9

Root cause, parts and sources →

5 Water pump failure

verified How widespread: Common

How it shows up

coolant drip from the weep hole below the pump
coolant loss; coolant staining on the front cover

Its other signs

whine or growl from the front of the engine
overheating with NO external leak (the classic sign of a spun / cracked plastic impeller: the pump turns but moves little coolant)
pieces of plastic impeller found in the coolant filter

How to tell it apart

visual inspection at the weep hole and front cover
check for water-pump shaft play
if overheating with no external leak and the coolers/gaskets check out, suspect a spun or cracked impeller

Usual fix

replace the water pump (units with a metal impeller are preferred); replace the thermostat and degas bottle cap at the same time; refresh coolant

Root cause, parts and sources →

Other symptoms on the 6.0 Power Stroke (2003-2007)

Hard start, long crank or no-start Stalls or dies while driving Loss of power, limp mode or derate White smoke from the exhaust Overheating or temperature creeping up Ticking, knocking, rattle or whine Misfire, rough idle, hesitation or surging

Everything on the 6.0 Power Stroke (2003-2007)Its recalls and bulletins

Order: how widespread each failure is in its record (near-universal, very common, common, occasional, rare), then the number of NHTSA owner complaints that match its keywords. Complaint counts are keyword matches, not a manual review of each complaint. A symptom listed here means the failure is documented with that sign; it is not a diagnosis of your truck. Tiers: verified, aggregated, contested, data-gap. How we tier and source facts.