ACtion Magazine - July/August 2014 - (Page 33)

Ford 6.4L Powerstroke By Jacques Gordon The Ford 6.4L Powerstroke engine has one of the most complex cooling systems on the road. Servicing this system is not for the novice; the service manual's flush-and-fill procedure is 78 steps. The job is a lot easier with an air lift tool. This cooling system works extra hard because it absorbs heat from the exhaust system. There are two EGR coolers, and the number 2 (vertical) cooler has a tap that supplies coolant to the EGR valve. Coolant exiting the EGR valve returns to the degas bottle, while coolant exiting the EGR coolers returns to the engine's cast aluminum front cover. Just for comparison, the water pump moves 125 gal/min at 3000 engine rpm, which is a 25% higher flow rate than the water pump in a 400-horsepower LS-1 Corvette engine at redline. There are two thermostats in the front engine cover, but they share a single outlet. They clip into the thermostat housing, and a YouTube video shows an aftermarket tool for installing them that includes a go-no-go gauge for the longer thermostat. The short thermostat functions normally to control coolant flow through the radiator, while the longer one bypasses the radiator circuit and allows coolant to return to the water pump. The longer thermostat has been the subject of a recall: failure (hyperextension) causes radiator leaks, and an updated thermostat has been released to fix this problem. Both radiator hoses have also been updated with double O-rings to prevent minor seepage that causes a release of cooling system pressure and subsequent cavitation. There is also a recall (TSB 11-12-4) requiring replacement of the dual-port degas bottle with a single-port bottle (some folks just block the upper port). Cavitation is an issue in these engines, and using the correct coolant is just as important as using the correct oil. A notice in the service manual warns: "Not all coolants contain a nitrite additive package. Failure to have nitrite in the cooling system may result in major corrosive damage to the engine cooling system components." There is a special Motorcraft additive with the right coolant chemistry for this engine. If coolant temperature at start-up is less than 136˚F (58˚C), the Powertrain Control Module (PCM) will estimate how long it should take for the coolant to reach thermostat opening temperature. If the coolant does not reach the predicted temperature, the PCM will set trouble code P0128 or P007B and the malfunction indicator lamp will be illuminated. Other cooling system codes are P0217 (engine over temp), P1285 (cylinder head over temp), P1299 (cylinder head overtemp protection active), P0125 (insufficient coolant temp for closed loop fuel control), and P0480, P0481 and P0482 that indicate cooling fan malfunctions. "Over temp protection" means the PCM has reduced the engine's power output to control temperature. When looking up service information for this engine, make sure to check for the latest TSBs too. Many have been superseded over the years, particularly those for the cooling system. ❆ Part No. 795-01 Cadmium-Free Braze Al Aluminum Brazing Kit Featuring DAYCOAT Advanced Flux Coating Technology photo: Richard McCuistian TM BrazeAl BrazeAl BrazeAl: The Solution To All Your Aluminum Brazing Needs! TM Coolant ﬂow to the EGR valve is throttled. Call Johnson Mfg. @ 800-747-0030 or S.A. Day @ 888-735-2805 www.johnsonmfg.com johnsonmfg@aol.com www.saday.com info@saday.com Reader Reply July/August 2014 * ACtion 33 http://www.johnsonmfg.com http://www.saday.com http://www.johnsonmfg.com http://www.macsw.org/imis15/MACS/Publications/ACtion_Reader_Reply/MACS/Publications/ACTION/ACtion_Reader_Reply.aspx?hkey=ac24bddb-c045-442a-813c-cbf05f88ac4d

Table of Contents for the Digital Edition of ACtion Magazine - July/August 2014

Fire truck A/C
The air we breathe
Outlook
Freeze Frame
Leonard's Law
Virtual View
Service Port
Last Watch
Member Profile
By the Numbers
Cooling Corner
Industry News
Association News
New Products

ACtion Magazine - July/August 2014