6.4L Power Stroke Maintenance Buyer's Guide (2008-2010)

2008-2010 Ford F-250 F-350 6.4L Power Stroke

The 6.4L Power Stroke makes big, smooth power through its compound turbos and common rail injection, and it can be a great truck to own. It is also the least forgiving of neglect of any Power Stroke. Water in the fuel, a leaking radiator, cracked up-pipes and oil thinned by fuel all cause expensive damage if they are ignored, and all of them are preventable.

This guide covers what to check, what to replace and in what order, with the parts we carry for 2008-2010 Ford F-250 and F-350 Super Duty trucks. Every product card lists the fitment as it appears on the product page, and the product page has the final word on fitment for your exact truck.

Quick answer: what to do first on a 6.4

Protect the fuel system. Change both fuel filters on time and drain the water separator at every oil change. Water and debris are what kill the high pressure pump and injectors.
Check the oil level every couple of weeks. If it is rising, fuel is diluting it. Change it now, and run 5,000 mile intervals.
Inspect the radiator. White crust or rust along the plastic end tanks means it is leaking or about to. Replace it with an all-aluminum unit before it fails on the road.
Listen for a hiss and look for soot on the firewall. Cracked up-pipes are common and cost power.
Watch for coolant loss with no visible leak. That points to an EGR cooler.
Service the 5R110W every 30,000 miles and go through the front end before it starts to wobble.

What makes the 6.4 different

The 6.4 shares the 5R110W transmission and much of its chassis with the 6.0, but the engine works very differently. That matters when you shop for parts and when you read advice online written for the 6.0.

	6.4L (2008-2010)	Why it matters
Fuel injection	Siemens K16 high pressure common rail pump and piezo injectors	Extremely sensitive to water and debris. Clean fuel is everything
Lift pump pressure	About 3-8 psi from the frame-mounted HFCM	Do not use 6.0 fuel pressure numbers (45 psi and up) on a 6.4
Turbos	Compound: a variable geometry high pressure turbo fed by a larger low pressure turbo	Up-pipe and exhaust leaks cost power and spool
Emissions equipment	EGR with two coolers, oxidation catalyst and DPF with regeneration	Regeneration can dilute the oil with fuel
Radiator	Aluminum core with crimped plastic end tanks	The single most common 6.4 failure
Cab	Designed to be lifted for major engine work	Big jobs add labor, so do related repairs together

6.4L Power Stroke service schedule

Ford's normal intervals assume highway miles with few regenerations. Most 6.4 owners should follow the severe column: towing, idling, short trips, dust and stop and go driving all count.

Item	Spec	Normal	Severe / towing
Engine oil and filter	15 quarts with filter. Low ash oil required (API CJ-4 or later). 15W-40 for towing in warm weather	10,000 miles or 6 months	5,000 miles or 6 months. Most specialists recommend 5,000 for every 6.4
Oil level check	Look for a rising level (fuel dilution)	Every other week	Every other week
Fuel filters (frame and engine)	Replace both together	20,000 miles or 24 months	10,000 miles or 400 hours
Water separator drain	Yellow quarter turn valve on the frame-mounted HFCM	Every oil change	Every oil change and any time the water in fuel light comes on
Coolant	Motorcraft Premium Gold, about 30.6 quarts (7.66 gallons)	First change at 100,000 miles / 6 years, then every 50,000 miles / 3 years	Check additive level every 20,000 miles
5R110W automatic	Motorcraft Mercon SP only. Replace internal and external filters	30,000 miles	30,000 miles
ZF6 manual	Mercon V, about 5.8 quarts	100,000 miles	60,000 miles
Transfer case	Confirm the fluid in your owner's manual (Mercon LV or XL-12 depending on the case), about 2 quarts	150,000 miles	60,000 miles
Air filter	Replace by the restriction indicator	Inspect every oil change	Inspect every oil change
Front end inspection	Track bar, ball joints, tie rod ends, drag link	Every oil change	Every oil change

Capacities are approximate. Fill to the dipstick or cold fill mark, and confirm specs in your owner's manual.

Fuel system: the part you cannot neglect

The Siemens K16 high pressure pump can produce more than 24,000 psi and feeds piezo injectors with very tight tolerances. When it gets water or debris, or when its supply runs short, it can fail and send metal into the injectors and rails. At that point the repair is usually the pump, all eight injectors, the rails and lines, and a fuel tank flush. That repair commonly runs well over $6,000 at a shop.

Prevention is cheap by comparison:

Change both filters on schedule. The primary filter lives in the horizontal fuel conditioning module (HFCM) on the inside of the driver side frame rail, with the lift pump and water separator. The secondary 4 micron filter is on top of the engine beside the oil filter housing.
Drain the water separator at every oil change, and immediately if the water in fuel light comes on. The factory filter interval alone is not enough.
Buy fuel from busy stations, and do not ignore a low supply pressure or a P0088 code.
Supply pressure from the factory pump is only about 3-8 psi, checked at the Schrader port on the fuel cooler. The computer cannot tell how much fuel is reaching the high pressure pump, so a weak supply can go unnoticed until damage is done.

An aftermarket lift pump with extra filtration and better water separation is the most popular insurance on a 6.4. It adds filtration before the factory system and keeps the high pressure pump fed.

Best for most

FASS TSF16100G Titanium Signature Series 100GPH Fuel Lift Pump

FASS lift pump with added filtration and water separation for the 6.4. Feeds the factory system clean, steady fuel.

Listed fitment: 2008-2010 Ford F250/F350 6.4L Powerstroke

6.4 Power Stroke Maintenance Guide (2008-2010) | Alligator Performance

Quick answer: what to do first on a 6.4

What makes the 6.4 different

6.4L Power Stroke service schedule

Fuel system: the part you cannot neglect

Engine oil and fuel dilution

Radiator, cooling system and EGR coolers

Radiator

Coolant and front cover

EGR coolers

Up-pipes, turbos and charge air

Transmission

5R110W TorqShift automatic

ZF6 six speed manual

Steering and front end

Other known 6.4 weak points

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