[Laguna Freak]

My 2006 6.0 runs great! I bought it in 2015 with only 19,000 mile on it. It has 145,000 miles on it now. It has been studded, deleted, oil cooler upgrade, and STC tuner since 21,000 miles. I change Schaeffer Synshield oil in it every 20K to 22K miles and test the oil every change. The oil analysis is always in exceptionally good condition exhibiting at least 30% service life remaining with nearly zero wear metals. In the last year I have replaced all 4 driver side fuel injectors. Injector 6 failed a year ago and 4 failed yesterday. So today I replaced 2, 4, 8 to be done with the driver side.

I've had an ongoing oil cooler backflush regimen going for about 3 months. After the initial full cooling system chemical flush and oil cooler backflush, my ECT : EOT would stay in spec for about 200 or 300 miles and then EOT would creep up or spike. Each time I drain to flush there is more blackened sand in the coolant catch bucket. I also installed a Mishimoto w/Wix bypass filter 3 months ago. Most recently, I drove about 400 miles before the ECT : EOT got out of spec. I've been losing coolant out the degas cap and from the hose connection at the bottom. The bottle and cap are 1 year old and I finally got the hose at the bottom to stop leaking with a tighter clamp.

I did a cooling system pressure test and a block test today. The pressure test got up to 20 psi pretty quick under acceleration and the block test fluid turned from blue to green (not from blue to yellow) in about 3 minutes, and there were bubbles coming up in the block tester every few seconds. Do I have a leaky head gasket?

This truck is stupid quick on acceleration. A local performance diesel mechanic who test drove it told me it might be the quickest truck he's ever driven. At 30 to 40 mph it will spin the all terrain tires when you mash the accelerator. Is my Performance tune too hot? Might I need to o-ring the head gaskets for this tune or is that a waste of money? I've got a few more minor parts replacements to do including body bushings so if I need to do head gaskets now, I want to do all I can to be good to go for another 5 years.

Help please!

 

[bismic1]

What coolant is in it?
Stock injectors or aftermarket/larger?
Still have a functional EGR system?
What brand of oil cooler was installed?

Sounds like head gaskets to me, and assuming so .... I would definitely install o-ringed heads.

I'm not a fan of oil change intervals over 7500 miles (or at most 10,000), let alone 20k+. I don't care what oil you use or what the UOA shows, I have yet to see an oil analysis that can predict stiction.

 

[cfherrman]

A few things I can pick, not trying to insult or anything.

A oil change like that on a huei is asking for trouble, do not go that long I don't care under any reason, you are risking your fuel system along with your engine. One of the weak points of the 6.0 is you cannot change the cam without a full rebuild of the engine, so why risk flatting the cam?

You only got 150k out of injectors tells me you are not changing fuel filters or you are getting crap fuel or something else.

Truck coolant should not go above the cap pressure, this is typically head gaskets, one of the weak points of the 6.0 is a head gasket is hard to get right when you change it so I'll point to who did the studs, but I'm not there so I could be wrong.

How are you doing the head cooler flush and what coolant are you putting back in? I would guess you spent more money on coolant than a oil cooler already or you are not doing it correctly.

Just trying to help not hurt.

 

[bismic1]

Hot tunes (and probably aftermarket injectors) and an under-performing oil cooler - sounds like a good combination to cause a head gasket leak even when studded.

 

[Laguna Freak]

I followed the TSB’s and sources posted on this forum to do the chemical flushes and follow up distilled water flushes. The last 2 times I backflushed oil cooler only was done done entirely through the oil cooler with compressed air, water hose, CLR / Restore / Restore Plus soak of oil cooler only followed with compressed air and extensive water hose flush. Each oil cooler backflush results in ECT : EOT delta not exceeding 5 C for the first 200+ miles. Then delta starts rising. Always more blackened sand in the bottom of the catch bucket when I drain the coolant.

Aside from the mods / upgrades in my OP, engine is stock. In short, I applied all known and well-documented remedies to the 6.0 weak links. Please re-read it if needed because some of your relevant questions other than coolant are answered in my OP. I switched from Gold to ELC concentrate coolant + distilled water when I did the chemical flush in October. I even did two full distilled water fill, run, and flush after the chemical flushes.


Everything I’ve read for 10+ years says Ford diesel fuel injectors commonly start failing around 120K miles. Often sooner. Even in 6.7’s. If you can document otherwise, I’d be interested in reviewing your sources. As far as I can substantiate, I have extended my injectors’ life by at least 20% through my use of fuel treatment.

Yes, I too look to the long established and reputable diesel shop that did my studs, etc in 2015. Only solution is use someone else. That said, I have heard several times from several reliable industry sources that sometimes head gaskets fail on studded engines. Thats why I asked about o-ring. Thanks bismic1 for the counsel on that.

Regarding stiction of injectors, it is caused by highly pressurized fuel deposits and/or internal component wear due to lack of lubrication in ULSD fuel. Bio-diesel fraction accelerates these issues. The engine oil drives 6.0 injectors hydraulically. It does not lubricate the fuel passages to prevent stiction.

I’m a lubricant and fuels expert. Its how I make a living. If you know little or nothing about lubricant and hydraulic drive oil physical properties and chemistry, please try to refrain from offering opinions based in 1970’s technology and old wives tales. They are not helpful to anyone. Proven technology advances applied by a handful of mfrs have produced engine oils that perform 5x longer than Rotella and still demonstrate the capacity to go further. This is why many OTR fleets run oil change intervals far greater than 50,000 miles. If you are a CLS, Chemist, or other Accredited industry expert who wishes to claim otherwise, please post up and refute this claim.

Otherwise, I appreciate your opinions in the fields where you have demonstrated expertise through experience or industry accreditation.

Hence the title of this thread.

 

[Laguna Freak]

Hot tunes (and probably aftermarket injectors) and an under-performing oil cooler - sounds like a good combination to cause a head gasket leak even when studded.

In your experience wil o-ring heads permit me to keep running this Performance tune? I like it but not $6K worth every 5 years.

 

[Laguna Freak]

Hot tunes (and probably aftermarket injectors) and an under-performing oil cooler - sounds like a good combination to cause a head gasket leak even when studded.

OEM injectors. Like you, I am a proponent of most OEM components.

 

[bismic1]

Everything I’ve read for 10+ years says Ford diesel fuel injectors commonly start failing around 120K miles. Often sooner. Even in 6.7’s. If you can document otherwise, I’d be interested in reviewing your sources. As far as I can substantiate, I have extended my injectors’ life by at least 20% through my use of fuel treatment.

Regarding stiction of injectors, it is caused by highly pressurized fuel deposits and/or internal component wear due to lack of lubrication in ULSD fuel. Bio-diesel fraction accelerates these issues. The engine oil drives 6.0 injectors hydraulically. It does not lubricate the fuel passages to prevent stiction.

I’m a lubricant and fuels expert. Its how I make a living. If you know little or nothing about lubricant and hydraulic drive oil physical properties and chemistry, please try to refrain from offering opinions based in 1970’s technology and old wives tales. They are not helpful to anyone. Proven technology advances applied by a handful of mfrs have produced engine oils that perform 5x longer than Rotella and still demonstrate the capacity to go further. This is why many OTR fleets run oil change intervals far greater than 50,000 miles. If you are a CLS, Chemist, or other Accredited industry expert who wishes to claim otherwise, please post up and refute this claim.

Otherwise, I appreciate your opinions in the fields where you have demonstrated expertise through experience or industry accreditation.

Hence the title of this thread.

Just to correct misconceptions, injector spool valves (high pressure oil system) exposed to dirty oil, too thick of an oil, or contaminants can, and do stick. In a 6.0L, the term stiction is almost always used to refer to these spool valves (primarily at the end caps), even though it is possible to also happen on the fuel side. Ford issued SEVERAL training presentations on this btw - in response to your old technology / old wives tales comments. Maybe you need to read a little more on the design and operation of the 6.0L injectors.

I am at 228k miles on my original injectors - still working fine. 145k is well below what I would expect. I have close connections to Techs and for years had access to 6.0L information (Ford and International). I have no need to try to look for statistics on that. I will say that Ford made several GOOD improvements on the early injectors (diamond like coating, injector clevis support, etc) that significantly improved their longevity. Even so, Ford identified low fuel pressure as the #1 cause of injector failure...followed CLOSELY by stiction (high pressure oil side).

Well, I wish you luck, it seems clear you don't need any help from this forum. I have a masters degree in chemical engineering btw, retired recently with many years industry experience, fwiw (clearly that provides me with no specific 6.0L expertise).

 

[Laguna Freak]

bismic1

I appreciate your feedback, knowledge, and experience. Your 228k miles on original injectors is the only instance I’ve heard of going that long. Duly noted as is your qualified opinion.

If I didnt desire the help of this forum, I would not have posted. So on that comment we will also disagree.

 

[cfherrman]

Your responses just drove out everyone that will help you.

 

[bismic1]

I will add two opinions (since asked directly on one of them).

First - there are quite a few really smart people that have arrived at the conclusion that studs alone are not going to be sufficient with SOME of the hotter tunes (fuel timing plays a big role in cylinder pressure). Call Kill Devil Diesel and ask why they sell o-ringed heads.

6.0 Engine Components

KillDevilDiesel

killdevildiesel.com

Second - as @cfherrman posted, the only thing that really concerns me about a high mileage 6.0 is a potential camshaft failure (and subsequent lifter failure), or potentially a reverse order failure (lifter then camshaft). One of these failures can ruin the motor (I guess so can an injector dumping a bunch of raw fuel). I am just not convinced that we have high-quality cam shafts (metallurgy and heat treat). I have no comment on what extended OCI's might or might not do with rotating elements, high load components, impact force, etc. However, I will say that proper lubrication is essential and film strength, viscosity, and load bearing capability all play important roles (in addition to the anti-wear additives). I have no intention of guessing as to what OCI is necessary to protect against catastrophic failure of an engine. UOA is good, but pushing an oil to the limit may not be the best decision. YMMV.

 

[Laguna Freak]

I agree 100 % with what you guys are saying about lubrication. Yes, film strength / load carrying capacity is of critical importance. Even more so in the severe hydraulic applications like the injector operation of the 6.0.

With respect to straight up friction elimination which eliminates wear and thus wear metals, oxidation resistance and inhibition, and capacity to neutralize combustion by-products, capacity to resist aeration, and capacity to carry other contaminants to the filter there are other chemistries present in modern high tech lubricants which perform these functions.

FTIR Spectrometry absolutely informs the analyst of the condition of the lubricating or power transmission oil and all of its component chemistry or contaminants.

We have volumes of documentation of million mile engines that operated under heavy load with 40,000 to 60,000 mile drain intervals in which analysis reveals component parts are within factory new specifications. This is a common occurrence in my world.

That said, I am thankful for your thoughts on leaky head gasket, your concern re; lubrication, and thoughts on the o-ring gasketing. Killdevil was presented to me as an option. I have not researched their heads yet. Thanks for including that link. I am leaning toward having my heads machined for o-rings if they are all good.

 

[cfherrman]

How many of those engines were heui?

 

[bismic1]

How many of those engines were heui?

Exactly, and how many were 6.0's with their inherent lifter and cam issues. Comparing different engines to each other is simply not applicable - which was the central point to the second point in my previous post. VERY VERY few 6.0L's reach 500k miles (or peg the hour meter), let alone more.

Even the 7.3L HEUI injectors were more reliable due to internal design (even though significant improvements were made in 04), so not all HEUI's are even the same.

A couple of examples of 6.0L specific information on early injector failure (including failure of all 4 on one side due to one injector sealing washer failure) are attached.

 

[Laguna Freak]

How many of those engines were heui?

I don’t know how many. I never really paid attention to HEUI as a qualifying component of performance but I will now that you mention it. Maybe I’ll get back to you with the right answer. I do know many are Caterpillar engines dated all the way back to HEUI introduction. If I’m not mistaken, the most recent tear down and analysis we did was on a 2015 engine. We also tested some SynShield oils on 6.7 Fords that were abused to confirm and document performance before the CK oil specs were introduced.

Note; the million mile factory original specs / tolerances does not apply to the injectors but does apply to crankshaft, camshaft, pistons, rods, valve-train, etc. You ever seen a million mile engine that still showed the cross-hatch machining marks in the cylinder liner? Its impressive.

I’ll see if I have a weblink to a presentation that I can share. Everything I have saved are very large data files. Likely not suitable to upload here.

 

[Laguna Freak]

Exactly, and how many were 6.0's with their inherent lifter and cam issues. Comparing different engines to each other is simply not applicable - which was the central point to the second point in my previous post. VERY VERY few 6.0L's reach 500k miles (or peg the hour meter), let alone more.

Even the 7.3L HEUI injectors were more reliable due to internal design (even though significant improvements were made in 04), so not all HEUI's are even the same.

A couple of examples of 6.0L specific information on early injector failure (including failure of all 4 on one side due to one injector sealing washer failure) are attached.

Am I reading that correctly that oil viscosity increase is “the precursor” to too much oil in the end cap which ultimately results in stiction due to spool valve malfunction?

 

[cfherrman]

Irc stiction is from having dirty oil too often.

6.7 are not heui, not made by the same people as the 6.0

Very few engines are heui because when people don't change oil they get expensive, so companies abandoned heui.

We are now in a pointless loop

 

[Laguna Freak]

Thanks guys!

 

[bobferber]

bismic1

I appreciate your feedback, knowledge, and experience. Your 228k miles on original injectors is the only instance I’ve heard of going that long. Duly noted as is your qualified opinion.

If I didnt desire the help of this forum, I would not have posted. So on that comment we will also disagree.

I have 260,000 on 2004 excursion Original 6.0 injectors

 

[Laguna Freak]

Ok, back to the head gasket leak. I backflushed my oil cooler again today just to satisfy my curiosity before I get my heads o-ringed later this month. As I said above, my EOT : ECT delta was getting as high as 13 C though EOT only got above 88C (190F) when I was towing my RV. Then it got to 94C (201F).

Sure enough the coolant had the black particles in it again. Probably the equivalent of 1/4 to 1/2 teaspoon (measured with eyechrometer). The particles are hard but don't really feel like sand. I'm now sure they are combustion products in the coolant. During my post-backflush test drive EOT : ECT delta never exceeded 6C and dropped to 3C within 15 to 20 seconds of achieving idle speed.

So, the heads o-ring job is on the calendar along with new oil cooler, body bushings, 1,3,5,7 injectors, metal degas bottle y-pipe, and a few other odds and ends. If my heads are compromised, I may do the Kill Devil Diesel heads.

At any rate, you guys are convincing me that the heui does not tolerate engine oil drain interval extensions as far as I took them the last 125,000 miles regardless of the Lab's ftir analysis and kinematic viscosity analysis showing 100C viscosity @ 13.