← Coolant loss on all engines
Symptoms · 6.7 Power Stroke (2011-present)
6.7 Power Stroke (2011-present): losing coolant
2 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.
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.
verified
How widespread: Common
47 NHTSA owner complaints match it, out of 1,754 checked
How it shows up
- low coolant warnings or a slowly dropping degas-bottle level with no visible puddle (small end-tank seeps often evaporate on hot surfaces)
- sweet coolant smell after a drive, or white crust/dye staining along the radiator tanks and crossover tube
- water pump weep or bearing growl, most common past 120,000 miles
Its other signs
- rising coolant temperature while towing grades (points to a clogged/airbound system, not just a leak)
- elevated charge-air and transmission temperatures without a corresponding engine-temp spike - a SECONDARY circuit problem, easy to miss because the primary gauge looks normal
How to tell it apart
- a pressure tester and UV dye find nearly every leak on this platform - diagnosis is conventional
- check BOTH circuits - the secondary bottle is routinely ignored until it causes downstream symptoms (charge-air/trans-temp creep) nobody connects back to coolant
- treat repeated coolant loss seriously rather than topping off for months: chronic low secondary coolant cooks the intercooler (feeds Intercooler condensation ingestion + cold-side charge-pipe fatigue); chronic low primary coolant risks head-gasket damage on an engine that is otherwise unusually resistant to it (contrast this project's 6.0/6.4 head-gasket narrative, which does not transfer to the 6.7L's 6-head-bolt design)
Usual fix
replace the radiator; do hoses, cap, and thermostat(s) in the same job on a truck past 100,000 miles
Root cause, parts and sources →
verified
How widespread: Common
12 NHTSA owner complaints match it, out of 1,754 checked
How it shows up
- unexplained coolant loss with no visible external leak
- coolant odor from the exhaust or residue at the cooler-to-manifold joints
Its other signs
- white, sweet-smelling exhaust smoke, especially at idle after warm-up
- check-engine codes P045C and related cooler-performance codes
How to tell it apart
- pressure-test the cooling system cold and watch for an unexplained pressure drop with no external leak
- pull the EGR valve and inspect for wet, steam-cleaned intake passages, which indicate coolant intrusion rather than soot clogging
- on higher-mileage trucks, plan to service the cooler and valve together - a clogged cooler that restricts flow will quickly foul a new valve
Usual fix
replace the EGR cooler (a cooler with confirmed internal leakage cannot be cleaned back into service)
Recalls and bulletins
Ford 21M04
Root cause, parts and sources →
Other symptoms on the 6.7 Power Stroke (2011-present)
Hard start, long crank or no-startLoss of power, limp mode or derateWhite smoke from the exhaustOil leak, oil consumption or rising oil levelTicking, knocking, rattle or whineMisfire, rough idle, hesitation or surgingDEF, DPF and regeneration warnings
Everything on the 6.7 Power Stroke (2011-present)Its recalls and bulletins