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Association of Diesel Specialists
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Powerstroke 6.0L, 6.4L and 6.7L

Powerstroke 6.0L, 6.4L and 6.7L

By Tony Salas

The Powerstroke engine families have given us headaches and sleepless nights since 2003 model year with the issues they suffer from. These issues include no start conditions, intermittent problems and an array of drivability issues that you would have to see to believe!

The Powerstroke 6.0L diagnostic is not the same compared to the newer generation 6.4L and the 6.7L. The HEUI nature of this G2 injector separates itself due to the high-pressure oil system and the fuel system. The newer piezoelectric common rail system on the Powerstroke 6.4L raises concerns with the fuel system because contamination is an issue. The newer Powerstroke 6.7L with the newer Bosch piezoelectric common rail brings issues with the electrical wiring system and the CP4 pump.
The time needed to access, repair, service and diagnose the issues of these three engine families means labor can be costly and time-consuming. And then there are the issues that are hard to explain.

We had a Powerstroke 6.0L come in with just an oil leak complaint. Since there was oil all over the top and the bottom of the engine, we decided to pressure wash and degrease the engine. Once the engine compartment was clean, we ran the engine to find where the oil leak was coming from. To our surprise we found oil leaks between the valve carrier and the cylinder head and another leak at the front cover, plus the high-pressure oil pump cover was leaking. For those of you who have had this experience, it can be frustrating to inform the customer that you need over $3,000 to repair these leaks. We decided to have the customer come down to the shop and show him the location of the leaks, which remarkably he understood.

Another customer brought us a 2005 F-350 with a 6.0L with an oil leak complaint. We degreased the engine and found the oil leak between the bedplate and the engine block. This requires the lower end to be disassembled after the cab is removed or the engine taken out. The oil pan was removed and we found small pieces of metal. Where did the metal come from? Removed the front cover to check the oil pump and more pieces were found, and the housing was badly scoured. Eventually we pulled the heads off, and the roller lifters were the cause. These are repairs that only came in for oil leaks!

As for fuel contamination on the Powerstroke 6.4L, ADS members have reported finding numerous trucks with metal or a brass-like metallic substance in the injectors inlets and in the tubes. Fuel filters have been contaminated with metal as well. This means flushing out the fuel supply, the high-pressure side and the return. If there was sufficient metal in the system, you also have to drop down the fuel tank and clean it as well. Labor once again is a concern, and service writers are faced with selling many hours to the customer for cleaning the fuel system.

A week ago while I was working on a class manual, a tow truck brought in a 2011 F-350 with a Powerstroke 6.7L. It had only 29,220 miles on it with a no-start complaint. First we asked our customer why the truck was not taken to the dealer for warranty repair. To our surprise the owner of this vehicle said that he refuses to deal with a dealer. I started to confirm the no-start issue and found the instrument panel displaying engine over temperature, engine reduced power, the wrench symbol and the engine pressure low message.

I confirmed fuel was not the issue and performed visual checks in the engine compartment. The batteries checked fine and cranked the engine with a no-start condition.

Since this vehicle is common rail I decided to attach the IDS scan tool and check for any diagnostic trouble codes and confirm engine data or PIDS. The IDS scan tool displayed a message, not a code that PCM was blank. It was not programmed and requested to have VIN plus the tag number entered. I was surprised to find this message since the vehicle was stock with no type of equipment added or evidence of a downloaded programmer used. I programmed the PCM and found a series of U codes from various modules in the vehicle. The PCM would not run a key on engine on (KOEO) or a key on engine running self-test. It displayed an error message but no additional codes. This was of concern since the PCM would not run self-tests and displayed U codes.

This truck reminded me of a 2004 F-250 that had a similar issue. This was a 6.0L that would not crank, reflash or run self-tests or program the PCM either. I have learned that these two engines use three connectors wired to the PCM. There is an engine connector, body connector and one for the automatic transmission. The PCM will operate but not display any PIDS or scan data if you remove the engine connector on either model. Please keep in mind that the Powerstroke 6.4L uses two connectors to the PCM.

Upon disconnecting the engine connector, the PCM became responsive and would run the self-tests. The PCM also would allow program updates from the IDS scan tool. In other words, the PCM acted normal with the engine connector was disconnected. When you reconnect the PCM, cycle the key, the PCM would become unresponsive, display blank PCM message all over again.
The 2004 F-250 was repaired by replacing the crank sensor, the engine harness and the PCM. We concluded that there was a short in the harness that partially shut the PCM down. We had found the crank sensor was not responsive and the harness had a short. The PCM was damaged from the short.

The 2011 F-350 with the 6.7L Powerstroke had an issue with the engine harness. But the PCM was still displaying U codes. Once we called the Ford dealer they said they had the harness in stock, which surprised us but also let us know there are issues with them. The PCM also needed replacement.
We have talked about the shorts and circuit issues that can affect the performance of a Powerstroke 6.0L. We have a bulletin which instructs you to disconnect the EBP sensor, the ICP sensor and even the glow plug control module. Now, we have found that the fan viscous clutch also can short and cause PCM issues.

Another check you can perform on these engines is you can disconnect the engine connector when you find a PCM responsive but with unusual errors and messages. If the harness is shorted, replace it and check PCM responsiveness.
To conclude, don’t get frustrated but understand and be patient. I have learned to accept these issues and continue to find new ones that arise from these platforms.
The new Powerstroke 6.7L is now in our hands. We have an engine and are working on a new class for this winter. The engine harness also has the injector wiring in it. This means that the injector harness, if shorted, may require the whole engine harness to be replaced. Stay tuned!

About the Author
Tony Salas is the ADS director of training. If you have technical questions or would like more information on ADS training courses, contact Salas at