UOA for my F250 2006 6.0 (most reliable vehicle we've owned). Oil changed with conventional Delvac Super 1300 every 5k. I started to notice diesel smell at the last oil change, so I short changed at 3,100 miles on the sample. I used Oil Analyzers since Blackstone's testing method is not a reliable way to get accurate fuel dilution. 240k miles on engine and 3,100 miles on the sample.
UOA: Ford 6.0 with 240k
- Thread starter Wizz
- Start date
I would be looking for a fuel leak, or weep if your smelling diesel. Oil will smell like hot oil, if that's whats leaking. If it's a heavy smell at the exhaust, might need to clean or replaces the injectors.,,,
+1 on looking at the injectors.
Have you had head studs installed?
Have you had head studs installed?
All oem, no studs, original headgaskets. Studs are a false God, the issue is the 6.0 head starts to dome then the HG starts unsealing, additional clamping force won't prevent that.
I replaced all injectors with Ford injectors 60k ago as preventative maintenance. Buzz test was good, will perform bubble test next...waiting on my IDS clone so I can perform a balance/contribution test, Autoenginuity's contribution test is misleading and not accurate.
I replaced all injectors with Ford injectors 60k ago as preventative maintenance. Buzz test was good, will perform bubble test next...waiting on my IDS clone so I can perform a balance/contribution test, Autoenginuity's contribution test is misleading and not accurate.
- Joined
- Jul 14, 2020
- Messages
- 185
Supposedly the 2006 and 2007 models were pretty reliable, but they quit making them to make the 6.4 for emissions reasons.
dnewton3
Staff member
Engine itself seems to be in fine condition; wear looks decent for 3k miles.
Other than fuel, no contamination to speak of.
You're obviously already aware of the fuel issue and have a plan. It's sad to think, but certainly possible that one or more of the replaced injectors is already faulty. I'm not intimately familiar with the area under the valve covers; is there a path for fuel to get into the oil other than the injector itself?
BTW Wizz ... less than 30 posts in almost 13 years; you, sir, are the model of restraint!
Other than fuel, no contamination to speak of.
You're obviously already aware of the fuel issue and have a plan. It's sad to think, but certainly possible that one or more of the replaced injectors is already faulty. I'm not intimately familiar with the area under the valve covers; is there a path for fuel to get into the oil other than the injector itself?
BTW Wizz ... less than 30 posts in almost 13 years; you, sir, are the model of restraint!
I’m curious to see what you mean by the heads “dome”.
That’s a new one for me and I’ve been working on them since 2007
I work with a guy who knows every nut, bolt and washer on a 6 liter. He calls it “ tenting “ where the middle 2 cylinders on each head sometimes doesn’t make good contact with the gasket no matter the clamping force. The cylinder head casts just aren’t very good on some trucks.
We have several at work. Some have never blown gaskets, some blew them at 30k miles. You can machine those heads a tiny bit and sometimes they will be ok, but the real answer is a GOOD set of o-ringed heads, and fel pro head gaskets. Studs aren’t necessary, at stock power levels
We have several at work. Some have never blown gaskets, some blew them at 30k miles. You can machine those heads a tiny bit and sometimes they will be ok, but the real answer is a GOOD set of o-ringed heads, and fel pro head gaskets. Studs aren’t necessary, at stock power levels
I agree with head castings can some times be poor. Flatness on both the head and block are crucial for proper sealing. However, Clamping force IS a factor, especially on modified engines. Most times gasket “fretting” is the real problem, which slowly get worse and cause fire ring seal blowout. Heat and heat cylcles can also cause block/head surface distortions/imperfections over time which will lead to what I mentioned previously.
O ringed heads won’t fix a block that isn’t flat. All the modified builds I do I strip the motor down and have everything resurfaced.
O ringed heads won’t fix a block that isn’t flat. All the modified builds I do I strip the motor down and have everything resurfaced.
My long gone 2006 F350 was my favorite truck to drive bar none. Straight piped that sounded sooo good and drove even better. I personally never had problems with that truck.
That is correct. Sorry about the late update. Uncompensated power balance test doesn't look bad, a couple of injectors are a bit low on the graph but nothing alarming. Going to pull another oil sample shortly at 5k mile interval. Relative compression test came back good, only one cylinder at 99% and the rest were at 100%. I was expecting worse at 244k miles. It passed the bubble test as well.
I believe Ford redesigned the head casting in '07, this gave it more internal strength/rigidity, they referred to it as "commonization." Another issue is when people go for a completely smooth mirror finish when machining the heads, that will cause issues with the HG as well. I will update with a report on the next sample in 2-3 weeks. If I continue to have fuel dilution issues (if over 3%) I may just change out the 2-3 injectors that are a tick low on the graph.
The '06 and '07 were very reliable as long as the casting flash was flushed out of the cooling system early on. Me and my firends have had great luck by using OEM parts and simply using it as a truck (no tunes, racing, etc). I also avoid "cleaning it out" by going WOT as a lot of problems have been created by doing that, I simply clean the EGR valve every 40k. It will be hard getting rid of this thing, a long block might be what I do when it does fail.
Last edited:
Those were some good trucks, they just had some issues from the factory that needed to be worked out. also many people traded in the 7.3 for the 6.0 and had no idea the difference in maintenance required to keep a 6.0 running good vs a 7.3. They assumed it was the same thing and it wasn't, aside from using compression to ignite the diesel they couldn't be any more different.
Got the second analysis done (switched to synthetic) and the fuel dilution dropped off for some odd reason. I am doubting it was a testing error as the first sample had a strong smell of diesel fuel, the second sample did not. Also the GC testing method is pretty accurate. Only thing I did was replace the original 243k mile fuel pump as a preventative measure. At the same time I did notice the secondary fuel filter element was physically twisted in the housing so I replaced it and inserted it correctly. So I am not sure how the dilution decreased so much, especially since I had 2k more miles on the second sample as shown below:
One of my friends used to be the parts guy at a Ford dealer Before we bought the F250 with the PowerStroke engine we talked to him and a good parts guy is wonderful because they see what parts are sold so to see the reliability of vehicles and he told us the only problem we see are when performance programs are used. I leave my vehicles as is and hope for the best.
Similar threads
