I have an option on a 2004 F-350 XL single-cab, 6.0 liter Powerstroke diesel, dually flatbed with manual transmission, 118xxx miles. I've read several reviews about the 6.0 diesel and swore I'd never touch one, but the price is right. I'm looking for advice on what to look for, what to be aware of, and so on. I especially want to know about red flags that should cause me to walk away, and things to look for that might indicate that this is one of the good ones. Your input is appreciated.

Post script: I do not know the history of this truck. Current owner has been moved into a nursing home. His daughter has power-of-attorney to sell and doesn't know anything about the original owner, from whom her father bought it, except he was short of cash at the time and needed to sell it.

 

If you are serious about buying a used 6.0L, you need to download ForScan to your smart phone. Buy an ELM327 OBDII adapter (I like BAFX brand - they do not all work flawlessly). You will need a WiFi one for an i-phone and a Bluetooth one for Android. Total investment of less than $40.

You will want to read the codes (ForScan is a very good code reader for the money) and check engine temperatures (oil, coolant, transmission and the two intake air temps - IAT1, and IAT2). You want to record these temperatures on a cold engine.

Still with a cold engine, you will want to start it. Again, tell the owner you want the engine cold when you arrive to test drive it. When you start it, you will want to be watching FICM MPower, LPower, and VPower. The FICM voltages will tell you if the FICM (Fuel Injection Control Module) is healthy and if the batteries and alternator are strong.

If it cranks for a while before starting, watch the (cold) cranking rpms.

It would also help to watch ICP pressure, ICP volts, ICP desired, and IPR % duty cycle. These values will tell you if the high pressure oil system (which the injectors operate off of) is healthy.

You will then want to run the truck until the engine is COMPLETELY warmed up (the coolant will be at least 190 degrees F and the oil will be slightly above that). It will take a good 15 minutes of driving to completely warm up. You will then want to drive the truck at highway speeds and record the 5 temperatures mentioned above. Pay particular attention to oil and coolant temperatures. The oil should be 8-10 degrees above the coolant temperature. A lower differential is good. A higher differential means the oil cooler could be getting plugged up. They plug up because of the fact that the Ford Gold coolant is not very "robust" and solids drop out of solution as well as gel forms if the coolant is worked too hard. Be sure to ask the owner "What coolant does it currently have in it?".

Then, when you get it back to the current owners house/location, shut the truck down and try starting it up again. Pay attention to how long it takes to start and monitor the FICM and high pressure oil data mentioned above.

If it cranks for a while before starting, watch the (hot) cranking rpms.

This is a lot to do, so it really takes two people if you are unfamiliar w/ the 6.0L.

There are youtube videos out on doing this. IIRC, DieselTechRon (DTR) has a video out on using the ScangaugeII to monitor these things. The concept is the same as with ForScan, it is just that ForScan costs 1/3 of what the ScanGaugeII does and it does more diagnostics.

Please ask questions if you don't understand or if you need clarification.

You also need to do all the "typical" things, like check the body for rust, paint and panel alignment, check tires, check brakes, check suspension, check air conditioner, check tires, check condition of interior cloth/leather/plastic.

I will post the DTR youtube video if I can find it quickly.

Be aware that 2004 was a transition year and the early 04's (up to production date of Sept 29, 2003) have a number of differences from the late 04's. This means they have different strengths and weaknesses. That discussion comes later if you buy the truck. It would help-us-help-you if we knew which one it was. The easiest way to tell is to locate the ICP sensor. A google search will show you where it is on the early 04 (which has an 03 engine) and also a separate search will show where it is on the late 04 (it is the same for 05's and up as it is for the late 04's). The ICP on the late 04 is on the passenger side valve cover. Below the CAC (Charge Air Cooler) tube to the left (passenger side) of the alternator (when looking from the front of the engine). If it is not there, then it is an 03 engine (ie an early 04) and the ICP sensor is in a spot that is a pain to get to (behind the turbo).

 

 

If getting a scan tool is too complicated (or even if it isn't), be sure to look for signs of coolant leaks on and around the degas bottle. They would show up as spots of powdery solids. This could indicate that the coolant system is pressuring up - possibly from head gasket leaks or an EGR cooler leak. The proper coolant level in the degas bottle is at or slightly below the minimum level indicated by the sticker on the side of the degas bottle.

Look at the exhaust and see if it is powdery or if it looks like coolant or raw fuel (liquid) has dribbled through the exhaust.

When idling a cold engine, remove the oil fill cap and see if it looks like excessive blow-by is occurring (you can turn the fill cap upside down and see if it will rest on the fill tube). Do this hot as well. Also, when hot, give it some accelerator pedal to increase the rpms and see if the blow-by increases. Diesels will always have some, it just shouldn't be enough to push up (and off) the filler cap.

Listen for squeaks and chirps in the engine compartment (when cranking, when idling).

Look at the oil level and the appearance of the oil on the dipstick.

Check the transmission fluid level (hot engine, when idling in park).

Look for fluid leaks (oil, coolant, diesel, transmission fluid, etc).

 

Here is one video