I thought I would re-post this since I have seen a few threads on the subject:
If you can afford it, I would recommend trying for a 2006 or 2007 year model - folks WILL DEFINITELY bargain with you. I think that buying a used 6.0L may be one of the best deals going right now. A lot of people have heard the horror stories and have traded them in. If you find a good price (which I have seen quite a few good deals) AND you have checked into the reputation of a local dealership on repairing the 6.0L - then GO FOR IT! So much depends on having a dealership that has competent techs to troubleshoot and work on any future problems.
If you are looking at used 6.0's here are a few considerations (along w/ the OASIS and CARFAX reports that are essential).
Some 6.0L weak points (things to check):
Look for signs of coolant degas bottle overflow (dry white residue on and around the degas bottle or no level in degas bottle).
Lots of idling can cause EGR problems. The 2005 and up model years have engine hours as a possible display. I would look at the hours on the engine (if it has this monitored) and divide the miles by the hours (is it below 25? If so, may have had lots of idling).
Even without much extended idling EGR valves can plug quickly - maybe negotiate for a new EGR valve. In fact, I would negotiate for them to pull the EGR valve to inspect it (have them show it to you when it is out and then you need to look into the intake). Check for wetness (w/ rear end jacked up or the truck parked on a "declne") and for excess soot. Wetness could indicate an EGR cooler leak (it could also be excess fuel and indicate injector and/or combustion problems). If the valve is gunked up, have them replace the valve. If the intake is real bad, you may push them to clean it as well.
Look underneath for oil leaks - some trucks have had a lot of them.
If you buy from a dealership, I would negotiate for them to install the latest flash of all 3 processors (PCM, FICM, ECM).
Negotiating for an extended warranty is always a good thing as well.
Try to find out about the routine maintenance:
∑ Filter change intervals on time? What kind of oil (CI 4 + or CJ 4 - one of these is required)?
∑ OEM filters? Look at them and see what kind they are. Aftermarket filters can cause MAJOR problems.
∑ Find proof of Transmission being flushed/changed - it is recommended every 30,000 miles.
∑ Any exhaust problems visible (i.e. lots of white or blue smoke)? White smoke may mean an EGR cooler leak if the smoke smells like coolant or a sign of injector issues if the smike smells like fuel.
Check for any FLUID leaks (as stated previously - LOOK SPECIFICALLY FOR OIL LEAKS - 6.0L are prone to many of these from many possible places!!).
CEL (Check Engine Light) on? Consider getting a code reader and check for DTC's. You can have active DTC’s without a CEL.
The Electronic Shift on the Fly ESOF sometimes fails due to vacuum leaks. Be sure to check this out (several times in and out of 4WD and/or take front wheels off to inspect).
Check for excessive wheel bearing wear (looseness), sway bar (end link looseness), or ball joint looseness. Ball joints and sway bar end links tend to go out in the 70k-90k range. Jack one side up at a time and see if each wheel moves top to bottom only, if so, it is the ball joints. If it moves in all directions then probably wheel bearings.
Check the coolant - it should have the Motorcraft Gold Coolant - anything else and there may be problems. Look in the "degas" bottle and inspect the fluid - it should be gold colored and there should be NO OIL visible (oil emulsified in water can show up as brown sludge). As previously stated, the degas bottle should not have white residue around the sides of it (possible overheating issues).
Any evidence of a tuner (aftermarket air filter, gauges, etc)? Tuners may or may not be bad. Some tuners are MURDER on the transmission. Some dealerships will cause you a lot of problems w/ them - even if you bought it that way used.
Aftermarket air systems could be a problem. Many of them (like K&N) do not filter as well and could cause issues. Up to 500 hp, the stock air system is best!
Try to find out if the original owner ever ran it empty on fuel or have plugged filters (fuel pressure below 45 psig can damage injectors)?
Then the common stuff I'm sure you know:
∑ Look at and smell the fluids. Make sure fluids not burnt, not too thick or dirty.
∑ Check the tires - abnormal wear?
∑ How do the brakes look? Any pads need replacement? Are the rear brakes excessively worn?
∑ All electronics working? Especially the AC (repair can be expensive)?
∑ Dents? Air bag been replaced, etc.
∑ See if he has any repair or maintenance records.
∑ Take off the price for windshield dings, paint chipped, torn upholstery, etc.
∑ Does the truck look too clean? Does it look like the oil was just changed? May be hiding something.
∑ Any extras - tool boxes, bumpers, etc.?
∑ Drive it - does it hesitate, stutter, or surge? Does it blow white or black smoke? When driving, brake fairly hard - note any pulls, pops, clunks, rattles, etc. How does it accelerate? You should romp on it pretty good. Drive in reverse and then back and forth - listen for clunks.
Add or subtract value based on condition, high miles, and presence of extras.
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Here are some things to consider after buying the used 6.0L:
After you buy a used 6.0L, I would IMMEDIATELY change the fuel filters, air filter, and then change the oil (and filter of course) to a quality oil. I prefer a 5W40 synthetic. As said many times before, use OEM filters (Racor, Motorcraft, or International for oil and fuel, Donaldson for the air). Just make sure the oil is properly diesel rated (CJ4 or CI4+).
I would also change the transfer case fluid and the differential(s) fluid.
I would ALSO replace the EGR valve with a new one, Be sure to clean the MAP sensor hose and the EBP sensor tube in the process.
Add a coolant filter, re-route the ccv vent and install gauges (fuel pressure, oil and coolant temps, boost and EGT). Gauges are very important.
Do not use anything other than Motorcraft Gold coolant or equivalent (actually Zerex G05 is acceptable also) and I would flush the coolant after I got it. Many people are switching to an ELC type coolant. It probably is OK, but I personally am not going to take that risk YET. Coolant health is as important as proper oil, proper filters, and good fuel and fuel pressure.
I would also take it to a dealership for the most recent flash.
While you are at the dealership, get a HEATED transmission flush. The heated machine is the only way to get fluid out of the torque converter. Use ONLY Mercon SP in the transmission. If your dealership does not have a heated trannt fluid machine (many don't), then you could drain the tranny fluid and drop the pan, inspect the screen (it usually does not need replacement) and then re-fill. I would probably repeat this process again after driving 100 miles or so. REMEMBER - the 6.0L had an external tranny filter that should be changed every 30k miles also (probably even a good idea to do that more frequently).
I would also consider VERY hard to pull the turbo and clean it.
The instructions for MANY of these jobs are in the Tech Folder.
Some things I like better about the late 2004 model years (production after 9/23/2003):
ICP sensor and location improved (early sensors have a high failure rate, the new sensor location is on the passenger side valve cover)
Better (higher capacity also) water pump
Higher capacity oil rails
Glow Plug Control module change and improved wiring harness
Improved Injectors (diamond-like coating)
Some things I like about 2005 model years and up:
Better high pressure oil pump.
Better front brakes and coil springs
Several harness upgrades to reduce chaffing of wires
Some EGR valve improvements
Some things I like about 2006 model years and up:
More EGR valve improvements
Commonization changes (in preparation for the 6.4L production)
Larger turbo oil supply and dain tubes
A Revised Machined Recess turbocharger
Bracket installed on the high pressure oil pump discharge (STC fitting) for production models after August of 2006.
Not sure of the date, but I believe it was sometime in 2007 when the new "one piece" fitting was installed on the high pressure oil pump discharge (replaces the STC "snap to connect" fitting that has a high failure rate).
Each model year seems to have its specific weaknesses also. More discussion on that later.
really there is no need to do that. that can be done with a volt meter(s).you would need to meters though to watch both at the same time. both sensor are thermisters. so all I need to do is dig out the coversion for the voltage to temp scales and post it.
Ill see what I cant find when I log on to fords website.
Another tip on buying a used 6.0L would be to make sure you try a "cold start". The reason to check on this is because some people might try to hide a cold start problem (which could be a FICM issue or injector issue) by warming it up before you get there.
Before you give it a test drive, open the hood and see if the coolant is warm or not. If you have a scangauge (or similar), it enables you to see the actual oil and coolant temps. As important as the cold start try is to check the oil and coolant temperatures. The temperature difference between them should be no more than 15*F with the coolant at operating temperature (I would expect it to be around 10*F when the engine warmed up).
Also important is to drive it for at least 15 minutes with a fair amount of highway driving - to get it hot (more time may be required if you are in sub-zero climates). Then try a hot start. The 2005 and up year models have a few potential leak issues in the high pressure oil system that can cause hard no-starts. Often times, these initially show up when the engine (oil) is fully hot.
Thought I would add ths summary even though some of it is a repeat from an earlier post:
Any year model can be a good deal .............. or not.
I will be as thorough as possible, only because most people are gun shy over the 6.0L. To try to minimize the negative posts, it may help to just let you know of most of the significant issues, and that there are fixes to all of them.
I would venture to say that most owners enjoyed far more reliability than the forums will ever indicate. If the trucks were heavily modded, especially without doing reliability upgrades, then they are/were likely to have issues. Ths means that buyers of used trucks can inherit major issues in some cases.
You need to know the weaknesses of them. More importantly, you need to know how it was taken care of. As said previously, the simplest thinig to do is to buy a scangaugeII before buying a 6.0L - many owners simply do not know how to take care of them or what to watch for. With the scangaugeII you can look at FICM voltage, ICP and IPR data, and oil vs coolant temp (do not buy one with an oil temp at greater than 15 degrees more than the coolant temp when accelerating or at 65 mph).
All year models have these potential weaknesses:
- low fuel pressure (a cheap blue spring upgrade is usually all they is required unless the engine is tuned, then you may need an aftermarket pump, etc)
- weak FICM (the Fuel Injection Control Module is susceptible to failure from low system voltage, poor factory software or flash, heat and vibration. FICMrepair.com can inexpensively upgrade it for apprx $300 and make it reliable. Even so, you need to keep the batteries and alternators healthy)
- plugging oil coolers from gelling coolant (this is mostly due to poor coolant maintenance, running low on coolant level, or small leaks in the head gaskets. Some say the Ford Gold coolant is junk, but if you flush it every 50k miles and don't have any of the afore mentioned issues, it should be fine. Switching to an ELC coolant will probably greatly reduce the possibility of gelling. A $120 coolant filter is an excellent idea)
- plugging oil coolers from casting sand (a $120 coolant is an excellent idea)
- nagging oil leaks - small hanging drops from the bell housing are common (They are almost never a realy problem per se - only a nuisance. Glow plugs, CKP, CMP, CAC boots, ICP sensors, and sometimes even bed plates are the issue. Easy to check for when purchasing a used truck)
- wiring harness chaffing (some year models are worse than others. 03, 04, and 05 might have the most common issues with them. You can look over wiring harnesses pretty easily when looking at a used truck)
- CAC boots leaking oil due to the ccv ventilation system (the crankcase vapors vent back to the turbo inlet. This can get the intake system quite oily. Sometimes the Charge-Air_Cooler boots will fail due to the oil soaking. Upgrade the boots and/pr re-route the ccv vent. Probably $200 in cost at the most)
- head gaskets, or actually head bolts (International used Toque-to-yield bolts. They do not handle stress, overheating, or overpressure very well. I would say that the majority of stock trucks that are well maintained do not have issues. However, if you let an oil cooler plug which leads to an EGR cooler rupture, then an intake will get filled with coolant and you will have failed head gaskets or worse. Significant overboost can also cause head gasket failures. Head studs coupled with good maintenance practices and you will be fine. If the truck was stock, well maintained, and will remain that way, chances are you will be fine with regards to head gaskets).
- heavy idling can soot-up an EGR system (minimize idling or install the high idle mod - easy and cheap).
- some people say turbos and injectors are weak, but if you take care of them, I have found them to be very reliable.
- Ball joints for some last only 80k - 100k miles. Others get much more. Greasable aftermarket ball joints resolve any issues (if you have an issue with them). Mine went 90k and were fine when I changed them (didn't need to).
2003 and ealy 04 (03 engines) weaknesses:
- ICP sensor and connector are common issues. Not real expensive to fix, but it is hard to get to the ICP which is under the turbo for these engines. Change out the connector AND the sensor if it fails.
- FICM (injectors) harnesses (Look the wiring over carefully, he fix is a new harness or repair/re-route the old one)
- HPOP (These early HPOP's occasionally would lose a bb in a machined port on the HPOP discharge. Repair can get expensive due to the tear-down time)
- cooling is usually fine, but the water pump is smaller than later model years
- braking is usually fine, but the brakes are smaller than later model years
2003 and ealy 04 (03 engines) strengths:
- high pressure oil piping systems have few issues
- the early EGR coolers have very few failures. They are a shell-and-tube design and pretty stout
2004 was a transition year, just depends on the specific engine you have. In general though, the following upgrades were made in 2004:
- late 04 is when the front cover changed and the larger water pump was installed
- late 04 was when the higher capacity oil rails were installed, but this brought about the leak issues described below.
- diamond-like coating was introduced on the injectors, but many 03 injectors have enjoyed 200k-250k miles of reliability
2005 - 2007 weaknesses:
- high pressure oil leaks (STC fitting, dummy plugs in the oil rail, and standpipes. Ford has upgraged compnents that are proving to be very reliable)
- revised EGR cooler, with plates/fins (relatively high failure rate on these coolers when the oil cooler begins to plug up. Keep the coolant clean and the oil cooler system unplugged and you will probably be fine. Install a BulletProofDiesel EGR cooler and forget about the possibilities)
2005 - 2007 strengths:
- reliable HPOP
- water pump (cooling)
- coil suspension
- at least for the 06 and 07 - fewer harness chaffing issues
- a revised machined Recess turbocharger for 06 and 07
- Larger turbo oil supply and dain tubes for 06 and 07
EGR Valve Position Measured (%)
Note: MEASURED (or sensed) EGR Valve Position, in percent, where a low value indicates a closed EGR valve (no EGR flow) and a high value indicates an open EGR valve.