Posted: 9-06-2006
FORD 6.0 LITER WOES CONTINUE TO PLAUGE EMS PROVIDERS
**NOTE: The following was received in response to several questions concerning ongoing problems EMS agencies are facing with Ford 6.0 liter diesels. Contact information is provided at the end of the report.
A/C compressor failure is a long story drag up a seat.
Beginning in 2004 on the E series a different A/C compressor was used. The problems which cause failure with this unit are as follows. The suction side line at the accumulator was not properly tightened causing oil to be lost from the system. While recharging many Technician's over charged the system with oil damaging the compressors. Also ambulance manufactures incorrectly charged the system with oil causing premature compressor failures. The previous compressor design was not as prone to this problem as it sat nicely on top of the engine instead of crammed underneath and very dependent on the correct amount of oil.
Now for the big goof with the thing, Ford technical service bulletin 06-13-2 lists a new PCM program which will run the engine fan more at idle. This is a desperation fix from Ford as they are hoping your crews are applying the emergency brake each time before they are getting out of their unit. This is a safety interlock required to activate the high idle on the unit. Without the unit idle increased above 1200 RPM you are just waiting for the next compressor failure. I suggest activating the high idle through the Ford supplied PTO harness bypassing the park brake input. This can be safely done since the PCM already must see Park input to achieve high idle, now you are not at the mercy of your crews to shut the unit off or press the parking brake to make the unit go to high idle to protect the compressor. [mlwood] Or require all your crews to set the parking brake every time they leave the unit idling.
Repeat A/C compressor failures are real easy to explain. Ford does not recognize the new compressors as having any plastic parts which will end up in the condensers and thus do not require replacement of the condenser when a compressor fails. This is true, but the metal parts coming from the compressors are of such that they are occluding flow of refrigerant causing extremely high pressures in the air conditioning system. Now you want to know why the technician didn't catch this when he repaired it? He replaced the compressor recharged the system ran it for a few minutes and everything looked fine. First hot day the unit goes on back to back runs the crew stops to eat leaves it idling (not on high idle cause they would have to push the park brake down) they come back to their unit and to no surprise it's not cooling. [mlwood] So get your technician to replace both the compressor and the condenser if the compressor goes out.
Fuel system problems, if you got awhile longer I wish for your sake you would listen to me I can fix all your 6.0L problems. First you need to understand a few things about the 6.0 in comparison to the 7.3. The 6.0 has a EGR system all you need to imagine is that it puts exhaust gas back into the intake. It also incorporates a Variable Displacement Turbo, very close tolerances inside this thing. And last but not least a different type of injector. When the 6.0L was designed the fuel requirement was for 40 Cetane fuel. All we need to now about Cetane is its the good stuff in Diesel Fuel. The problem is when you remove Sulphur from diesel fuel cetane goes with it. Well you guessed it they are not putting it back in the fuel. Navistar (manufacture of the engine) did a spot check across the U.S. testing the cetane level of fuel the highest they found was 36. The state of California requires a minimum of 50 cetane at the pumps and as you now can imagine no 6.0L engine problems in California. Low cetane fuel causes black ooze, gummy stuff almost roofing tar inside the EGR valve not allowing it to operate properly this in turn chokes out the engine remember I said we are putting exhaust back into the engine, well with the EGR valve stuck open we can't stop that. Coking deposits, very hard chunks, build up inside the turbo charger preventing the turbo from creating boost pressure and eventually damaging the turbo charger. None of this is Navistar or Fords fault. Cetane additive must be added to the fuel religiously. As for your injector failures remember I said there was a new design.
You may not know it but the crews are again at fault for injector damage along with restricted fuel filters. There is a part inside the fuel injector that operates at 30,000 PSI, when low fuel supply occurs (unit run out of fuel, operated nearly out of fuel or restricted filters) the components are slammed together at without the 30,000 PSI fuel cushion, instant injector death. [mlwood] In other words have your crews keep fuel in your vehicles (with Cetane additive that is.)
Sherwin Meharg
Fleet & Facilities Director
Vital Link EMS
1033 EMS Dr.
Batesville, AR 72501
smeharg@vitallinkems.org
870-793-3351
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We have had some EGR problems, but our trucks are on the road a lot and not idling so much so this helps with that, but we have replaced some EGR valves.
A/C problems are always an issue, but we find our medics set the emergency brake relatively religiously therefore not really any more problems with the 6.0 units than the other units. Ford has changed the PCM program more than once for our units also, in an attempt to solve some of these issues.
I think you might want to be careful disconnecting the safety interlock on the parking brake for a couple of reasons. 1) If high idle is engaged when the truck is placed in park this allows for the engine to be turned off while in fast idle mode when they back in the station, not allowing proper cool down and lubrication of the turbo. 2) This may actually encourage the crews to leave the unit without the parking brake engaged and the engine running at high idle (At least now if they leave the unit without the parking brake engaged it is not in high idle mode), and if an accident occurs who is responsible for altering OEM equipment.
We also experienced a problem with the turbo intake tube blowing off. To fix this, we fabricated a bracket to hold it in place (Ford has since built a bracket for this problem also).
We have not experienced injector issues, but we do change our filters frequently as dictated by our PM schedule, possibly avoiding those problems.
We have had a few issues with the 6.0 L engines but we have not experienced the long down times or the severe problems some departments have experienced.
Tony Hickerson
Administrator
Central EMS, Inc.
645 S. School Ave.
Fayetteville, AR 72701
479-521-5801
thickerson@centralems.org
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