Also.....doing the job yourself ensures that it gets done right in many cases.....YOU are going to take a second look at anything that seems a tad hinky.....as compared to the shop mechanic that MAY NOT give it a second thought....
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Also.....doing the job yourself ensures that it gets done right in many cases.....YOU are going to take a second look at anything that seems a tad hinky.....as compared to the shop mechanic that MAY NOT give it a second thought....
You're right Robyn.
Mechanics and shop owners have a somewhat different motivation than do owners. They are worried about come-backs and liability, as well as producing a satisfied customer (or they should be). Shops also rely on their mechanic staff to do all that, while trying to keep the best mechanics and make the shop profitable (the really talented mechanics usually go out on their own). Shops have a lot of competing interests, which is partly why they do the "As Long As We're in There" routine with up-selling every job that comes in. There are a lot of good mechanics out there and there are a lot that aren't. I've heard so many horror stories through the years from GM diesel owners.
Jim
I agree on the "Upselling" many times these things are done to "Cover the dealer/shops butt"
A side story.
My tenant that lives in the lower level of our place has a 2002 Jeep Cherokee with a V8
It has been giving issues off and on for a few weeks now.
I DO NOT WANT TO BE HER "GO TO MECHANIC" although on occasion I have wrenched on her rig to get it going so she can make it to work....(Important if I expect rent payment)
The Jeep started stalling.....I grabbed the scan tool and checked it out..../A failing crank sensor..
She took it to a shop close to her work....They installed the new sensor.....On the way home it died about 4 blocks from the shop....
Shop sends the mobile unit out and he determines that the tranny is burnt up and needs replacing.. Hmmmmmmmmmmmmmmmmmmm
She calls me and I told her....DO NOT DO ANYTHING.....NURSE IT HOME.
I check the tranny fluid....PINK AND SMELLS PURRRRRRRRRRRRRRRRRFECT.
Tranny shifts fine.
Every so often at light throttle the engine would just die....
Throttle position sensor and the idle air control are suspect in my book..
The TPS was replaced about 3 years ago due to a similar issue (Engine speed surging up and down)
I suspect the NAPA part that was installed (Made in China) is giving up....
Idle air control dirty with carbon and crud can and does cause stalling......
Sharis called another shop....told them the story....
Fella puts his scan tool on the JEEP and tells her she needs a new ECM
Nobody has hit on the IAC and TPS
She has been quoted MEGA $$$$$$$$$$$$$$$$$$$$$$$$$$$ to chase this anomaly....of which none of the FIXES will do anything accept take her money..
What I have seen so far is mechanics that rely waaaaaaay too much on the magic box scan tools.
If the tool does not tell them what's wrong....they default to a WILD ASS GUESS.....
They need to learn "Butt dyno" and basic automotive skills.
If the scanner is not showing anything then its not electronic (Generally)
Back in the day.....when a screw driver and a crescent wrench were king....We had to THINK
I digress
Glad to hear that the Daughter is interested in learning the art of swinging a wrench...
Definitely be good for her to have a good handle on all things automotive.....Then she will be able to know when she is being told BS....
Not much available in any auto parts store that's not made in china... They've all turned into Harbor Freight. (although HF is starting to grow on me... I bought a number of wrenches from them recently, including a 3' long 3/4" breaker bar - now that's a manly wrench!)Quote:
I suspect the NAPA part that was installed (Made in China) is giving up....
Yes indeed
Big Ma break stuff type wrench
I avoid screw drivers and such. Pretty much junk
I have a set of impact sockets I bought back in the 80’s when HF was mail order only
Still 100% shape and been beat unmercifully over the decades
I have several power tools from HF
No complaints
Just need to treat them with a bit of care as opposed to tossing in the truck with a heavy hand
I have a 12” double miter saw, a hand held band saw snd a few other tools
All are great tools
Several air tools including my air compressor came from HF
My old air compressor died after 30 plus years of serious abuse
Ran to HF and picked up the Squatty top compressor unit on wheels
Works great
The Cat project has already put 16 hours on the beast
I have one of their multi meters snd it’s been great too
Most stuff from HF is great for hobby shop or moderate use and will live a long time if taken any dirt of care of
Oil the air tools and be somewhat careful of plastic handles and such
I have an ancient horizontal metal band saw that still fills in when we need two machines
My Son in law picked up a nice Jet band saw that has the protractor head on it
He found it sitting in a driveway near his house with a sign FOR Sale
This model is about $1000 and we got it for $500
Just requires a very easy feed or the band will pop off
That was common in that model
But for the price ..: good tool
HF is my Toy store
I will not buy their 18 bolt stuff
The 1plus from Home Depot have been great
Have Ridgid brand too
Both great tools
I like having several tools that use one battery and charger
The lithium ion batteries are sooooooo much better than the old chemistry stuff
Got one of those battery chain saws
Great for that little job that you don’t want to go get the gas saw and fool with it....
Tools ... great toys for busy hands
Harbor Freight quality has really increased a bunch lately, it appears to me. However, so have the prices. Case in point - their "pro" 1/2" drive torque wrench is $109. I picked up a Craftsmen brand from Lowes for $89.
Casey
Looking great.
I have seen this view before a few times...... always a good feeling when ya get the crank in and start stuffing the little soldiers back in their holes.....
The sorting through the parts boxes is always fun....especially when others have torn stuff apart.
When the Dahooley came down the last time I knew it was going to be a lengthly period of time until it went back together.
Stopped at the grocery store and grabbed a few boxes of the various sizes of plastic zip lock bags.
Bagged and tagged all the bolts. nuts and sundry other small items.
Made the reassemble a breeze....No matter what was happening, a quick sort through the bags of goodies and whatever was needed was in hand and ready to go.
When the hood was closed for the final time ....all the bags were empty and nothing missing or left over.
Really makes me wonder why some folks toss all the bolts and such in a bucket and then have to sort through it all later....
Too much like work and frustration me thinks......
Yup... We used about 20 such cups for hardware during the Duramax head gaskets jobs, and I kept as much of the hardware as was practical with the items being removed. All of this speeds the reassembly process considerably. Unfortunately, the 6.5 was disassembled by someone who didn't know - who hadn't done this before, as evidenced by the fact that they ruined the original crankshaft getting it out of the block (gouged journals) and not protecting vulnerable inner parts from moisture (i.e. most of the lifters were ruined by rust and none of it was kept clean). There are about a dozen cups with hardware, but most weren't labeled (or the lettering rubbed off) and there appears to be a mixture of fasteners in some cups. Reminds me of the time that, as a teen in the '60s, I bought a basket case 1938 Harley Knucklehead for $75 that I turned into a bobber. Fun times! My spine winces a bit when I think of riding that bike. ;)Quote:
Bagged and tagged all the bolts. nuts and sundry other small items.
Sad to see stuff trashed.....but it happens.
I have the opportunity to purchase some new ARP head studs for my 6.5L for the same cost as new TTY head bolts. Is there any reason NOT to use head studs in my application? This is a stock 6.5L with 375K on the clock and no other issues other than a blown head gasket. John Kennedy recommends studs.Quote:
Originally Posted by More Power
Thanks,
Casey
I can easily make the case for TTY - which includes the quote you included in your post. What was not in that quote was the head gasket durability I saw with our 6.5TD Power Project, using TTY bolts (300K miles of mostly towing/performance miles without a single head gasket problem).Quote:
Originally Posted by arveetek
It's disappointing that "some" get perturbed when asked to provide support for their position. I don't understand it. If studs are better, state why you believe that... I have nothing to gain otherwise by promoting one type of fastener over another (I actually lost a vendor over this very issue). As an information resource (thedieselpage.com) I have more to gain by promoting the "best" option. There are several criteria for what could be considered "best". "Best" could defined as proven better - sorta like how the FDA approves new drugs (blind studies - direct comparisons). "Best" could be defined as being more than adequate for the vast majority of the owners while saving them a lot of money in the cost of fasteners. What's not "best" is theoretical or an arm chair opinion. I would ask the stud advocates to put some verifiable high mileage examples of head stud usage on the table to consider - like the following high mileage TTY head bolt example I talked about a couple of years ago - 772,470 miles, which backs up the story I did on the 751k C2500 Duramax RV hauler and our own 300k-mile 6.5TD Power project... Read more about high mileage Duramax trucks here: https://www.thedieselpageforums.com/...-March-updates
https://www.thedieselpage.com/images...2k-Duramax.jpg
It used to be back in the early days of the 6.2/6.5 that GM's head gasket suppliers hadn't figured out how to design a gasket that worked for these engines. Far too many head gaskets failed in these engines because of poor gasket design, and that's when the aftermarket (and others) began advocating for studs for the 6.2L/6.5L. Then one day Fel-Pro designed the best head gasket, and head gasket failures almost disappeared. Turns out that the problem was never the fastener but the gasket design. But, old opinions die hard. By the way... throughout the early years of the 6.2L diesel engine production, GM used head bolts that were not TTY. They were simply torqued to a specified torque value in steps... like stud nuts are now. GM could have stayed with non-yielding head bolts, but they switched to TTY early and continued through to the end of their own production of this engine, and AMG continued to use TTY when they took over 6.5 production.
So, to answer your question.... because of their elastic head clamping design that compensates for thermal cycles and gasket compression (and my own verifiable long-term experience/success with them), I prefer TTY, especially for the 6.5. Now, for the Duramax, if cost is taken out of the equation, it's more of a toss-up in choice except perhaps for a high power (2x+) application, then ARP's engineering data "begins" to sway my opinion. But, even that is simply theoretical. ARP's own ad claims in the Northern Auto Parts catalog, when talking about diesel stud kits, say that their studs are preferred among "racing" enthusiasts. That said, I'm quite content in my choice of TTY for Lil Red's Duramax because it has been retired from any sort of racing/dyno/nitrous duty. The 6.5 I'm putting together right now will get Fel-Pro TTY head bolts along with Fel-Pro head gaskets... just like our 6.5TD Power Project did in 1999. Besides, due to the limitations in fuel delivery of the DS/DB fuel injection system, the 6.5 can't be made to produce a horsepower level that justifies studs... in my humble opinion.
Jim
GM spent a buttload of $$$$$ designing things (Bean counters not included in the equation)
But even the best engineering will not always stand up to road testing by "Bubba"
I think you are pretty close to the mark....
The Monday morning quarter backers.....always...woulda, shoulda, coulda types always have an answer to every issue.. "My buddies uncles shop" does it this way......
Ah well.
Such is life....
I'd bet that "if" GM believed studs were best, they could contract with ARP or another manufacturer to provide head studs for the Duramax. DMAX has produced millions of these engines. That should allow for a pretty deep discount on quantity buying.Quote:
Originally Posted by Robyn
By the way, the engine shop I visited, to get my GMC's aluminum heads resurfaced, also builds Duramax engines for their retail market. They offer a 5 year warranty on their top of the line Duramax engines, and they only use ARP head studs and Mahle gaskets. The owner is a nice guy, and I didn't press him by asking "how he knows they're best?". I was there to make friends. Sometimes people forget or simply don't know how much experience I have with these engines - and how many people I've talked to in more than 2 decades. I always allow room for others to have their own opinion, even if it is based on theory or... If their position is fixed, I move on.
An additional item I found during the Duramax head gasket replacement project(s)... The Mahle head gaskets made for the Duramax don't seem to compress overnight after having the fasteners (either stud nuts or TTY bolts) torqued to their second-to-last torque setting (59 ft-lbs). When checked the next morning, the torque setting was still right where I left it. So, there's no need to pause overnight, then re-torque to 59 ft-lbs the next morning, before moving on to the last step in stud/TTY tightening.
Jim
Allowing folks their latitude is usually a great plan to make inroads.....
The folks that really irritate me are those that say.....WHATEVER IT IS ....You can't do it that way...."Why" BECAUSE....IT WON'T WORK.....
No explanation....just because....
Arrrrrrrrgh....
I haven't talked much about the injectors I used for the two Duramax head gasket projects discussed in this topic thread, and after having lived with the choices I've made for some weeks now, I think I have enough information to talk about the differences between the original VCO type injectors (stock type used in the LB7) and the more recently available SAC type that I installed in my GMC during the head gasket replacement.
First, a little background: The original 2001-2004 LB7 high pressure common rail fuel injection system operates at up to 23,000-psi fuel rail pressure. The more recent model year Duramax operates with up to 29,000-psi rail pressure. We all know that high pressure liquids can erode even hardened components. For example, the Duramax conversion motor mounts we sell here at thedieselpage.com are made from 3/16" plate steel cut from large sheets using a computer controlled water jet system. It cleanly and smoothly cuts steel plate like butter. The Bosch fuel injectors use hardened components designed to deal with the high pressure diesel fuel... but, there is a design difference between injectors made to operate at up to 23,000-psi and those designed to work at up to 29,000-psi. The aftermarket (S&S Diesel) began offering the SAC type injectors for the LB7 in about 2018, which combine some of the 29,000-psi nozzle components in an injector body that fits the LB7. Longer nozzle life is the leading ad claim. That's the upside... but, is there a downside? Turns out... yes...
According to the web site: https://powerdrivendiesel.com/differ...sac-injectors/ , the acronym VCO is derived from (Valve Covering Orifice), where SAC style nozzles utilize a different shaped orifice that is said to provide more longevity. The site didn't say what the letters SAC mean..., but they do mention a difference in the level of combustion rattle (noise) produced by the engine depending on which type of injector is installed - confirming what I experienced. I didn't know this before the SAC installation...
In real terms, there are a few differences you will notice the first time you start your LB7 Duramax after installing the new SAC injectors.
Originally equipped with VCO, my 2001 GMC got the new stock flow rate SAC type injectors during re-assembly. After all this work, the engine appears to start almost instantly with a much crisper "ccrraacckk" sound. While motoring around town, you can hear more combustion rattle in general along with a background of light secondary rattle (like shaking an empty soup can with a dozen BBs inside). I don't see anything in the way of smoke, either during a cold start (it's summertime) or when accelerating hard - boost goes to 20-psi. Seems to be very clean for a 141,000 mile engine. At secondary road speeds (55-65-ish) the increase in combustion rattle produced by the SAC injectors can be a bit annoying... it's as though the pilot injection has been reduced or is only marginally effective. Haven't had it on the Interstate yet. By the way, my GMC is running with a 100% stock factory-programmed ECM and without any sort of power adder. There is no SES light.
For Lil Red, I re-installed the very same factory original VCO injectors that this particular LB7 came with - now with just over 8,000 miles on it. Not surprisingly, the engine sounds exactly like it did before the head gasket replacement. Its combustion rattle is relatively quiet, just like it was before. In terms of combustion rattle, it's noticeably quieter now than the GMC... By the way, I went to considerable lengths to keep Lil Red's injectors clean and uncontaminated during dis-assembly, storage and re-assembly. I must have done a good enough job because the engine runs just as smoothly now as it did before all of the engine work.
The original VCO injectors in my GMC crew cab ran to about 120,000 miles before #2 set a fuel-rate balance code (P0302). Not long after, a local diesel shop installed a full set of VCO reman injectors for me (I know, I know... I should have done it...). After about 4 years and ~20,000 miles (now 140,000 miles total on the truck), I was beginning to see a little blue fuel smoke at a cold start that quickly went away and didn't return till the next cold start. It ran well enough with those reman VCO injectors, and the combustion rattle was just like it was with the factory original set of injectors. I decided not to re-install this 20k-mile set of injectors during the head gasket replacement because of the blue puff at a cold start - "as long as you're in there", I thought. By the way, I've always used a commercial diesel fuel treatment in this truck (lubricity, cetane, anti-corrosion, cleaner, etc.). I had originally planned on taking the GMC's injectors to a local certified shop for testing and cleaning (if they would do it), then re-install them, but doing the work myself saved so much money that I splurged a bit on new reman injectors.
Going forward, the only reason I can see for choosing the SAC type injectors is longer life (theoretical - yet unproven), which would be a good reason... but, I know now that the VCO type injectors offer a much quieter operation - and that's important to me as well.
What would I choose if doing the GMC again? I'm thinking I'd choose VCO... And, I would investigate the service life data and cost differences comparing reman Bosch injectors with new Bosch injectors as part of the decision making process, as well as looking to solve some of these injector problems on my own work bench using the available replacement parts. All that said, I'm glad I reinstalled the original VCO injectors in Lil Red.
Jim
Interesting stuff.....
Hey Jim,
I'm wondering if John could spin some new code to quiet the GMC down. See what he says.....
As an aside... During the opening phase of these two head gasket replacement projects I became acutely aware of the enormous cost potential, especially if a truck owner took the advice of the "replace it as long as you're in there" crowd and replaced or upgraded everything. Doesn't take long to cross the line in economic sanity.
As my work progressed, I assumed I'd need a water pump for the GMC, even though it had been replaced just 3 years earlier. I thought this because I could smell hot coolant after a drive, parking, then walking around the front of the truck. I just assumed the water pump seal had surrendered to the excess pressure, so I bought a new water pump from Kennedy (like most things I needed) so it could be replaced as part of this head gasket replacement project.
During the tear-down I noticed that most fittings/joints/connections in the thermostat housing area had been oozing coolant for quite some time. The coolant ooze had run down the front of the engine behind the fan pulley assembly, producing the hot coolant smell. That made me curious, so I then carefully examined the weep hole on the bottom of the water pump, to see if it showed any evidence of coolant leakage. That weep hole is somewhat hard to see - it takes some effort to be sure about it. Turns out the weep hole was bone dry and was without any dried coolant residue. So, there were no water pump seal leaks. As a consequence, I didn't replace that 3 year old water pump. It wasn't leaking then and still isn't. I left the brand new water pump on the shelf, "standing by, just in case" for the Lil Red project.
When Lil Red was at the same place in its head gasket replacement, I examined its water pump weep hole. Nary a hint of leakage... So, I kept the new Kennedy AC Delco water pump (with welded impeller) on the shelf. I've driven Lil Red about 4,000 miles and the GMC about 8,000 miles since replacing the head gaskets (now ~13 months after the fact - September 23, 2022). Everything remains perfectly dry and without a whiff of a coolant leak... After having done these two head gasket replacements, I now know that a water pump replacement is, by comparison, cake (I've participated in one complete WP replacement)... Besides, I still have that new Harbor Freight 3 foot long 3/4" breaker bar I mentioned a few weeks ago, just in case I need to remove the damper during a water pump replacement. ;)
I wondered about that. I suspect he's reading this thread.Quote:
Originally Posted by DieselDavy
Experience... you'd think that at some point a person would have a good handle on what to ask - live long enough and you'd become that wise old sage. Seems I'm still learning...
S&S has an info page that talks about and discusses the benefits of SAC. I should have asked them about downsides... didn't see any on their web site. I thought maybe I'd screwed up during the install because the truck was so much noisier with combustion rattle... Then I started doing a little research online... I also wonder about potential impacts to power and fuel economy - by comparison to VCO. I've been tracking fuel economy in the GMC... I'll report what I find when I have enough information to form an opinion. Jim
On edit (9/15/2021): Fuel economy so far... has been in the range of 15-17 mpg for mostly local driving, so my guess is that the fuel economy hasn't been affected all that much - that's about what it did pre-head gaskets with the VCO injectors. I'll know more when we drive it on the interstate for a few hundreds. The GMC has nearly 2,000 miles on it since the head gasket replacement.
On edit (2/1/2023): The GMC is coming up on 10,000 miles since the head gasket and injector replacement. I've gotten more or less used to the increase in combustion rattle. The engine runs smoothly, and continues to perform very well without any sort of problem. It's wonderful knowing that I can jump in the truck, and can go anywhere without worrying about whether or not the cooling system will dump its contents out onto the highway. We love this truck. I'd rather drive it than our Chevy Malibu, anytime, anywhere - for the room, the comfort, and the safety...
Sounds like a good thing to me! :D That's actually one of the things I don't like about the newer diesels... they are too quiet. I love the older, clattering diesels.Quote:
Originally Posted by More Power
Casey
When I brought our brandy new 2006 Duramax home, my wife, who had been around Diesels all her life, said "it's not a Diesel!" in all seriousness, thinking her husband had made yet another huge blunder! ;)Quote:
Originally Posted by arveetek
I think the reason that the newer diesels are so much quieter is to satisfy the "City dwellers" that are offended by everything.
The common rail and pilot injection technology really made all this stuff happen
Just to sort of play the devils advocate here...
After owning many diesels....OLDS 5.7...GM 6.2/6.5 a couple Detroit 2 strokes and a 3406E 500 HP Cat.
The interior cab noise levels does tend to beat ya up after a while....So why not make it quieter...
With the computer control and the pulsed injection....Does make the long trip much more relaxing.....
Likely has a lot to do with meeting emission requirements too....
Simple. Turn up the radio or turn down your hearing aid.
ROFLMAO
Pretty much......
Trucks used to be "Trucks"
These were hard working, hard driving beasts that offered little if any real creature comforts.
Rode like a buck board....
Power steering....Wasssssat ???
I had a 1967 IH 3/4 ton 4x4
Gawd that was a beast....The transfer case shifter looked like the Johnson bar off a late 1800's steam locomotive.. Damned lever weight 15 lbs Cast steel....
Now that was a truck.....Everything about it was brute force.....
No power steering either....let alone AC and other fluffy stuff we have come to expect...
Crank windows, no radio....Stereo with surround sound ....Say whaaaaaaaaaaaaaaaat...
What was that???Quote:
Originally Posted by DmaxMaverick
Back about 1992 or thereabouts my sister-in-law's husband (who owned a Ford diesel pickup at the time) test drove a then new 1992 Dodge 12v Cummins. I asked him afterward if he was planning to buy a Dodge... He said: "If I wanted a truck that rode like, drove like and sounded like a road grader, I'd buy a road grader." It was funny when he told it... He still drives Ford diesels... has a couple of new ones.. pretty quiet too.
Daughter doesn't think the GMC is too noisy either, and I don't yet have a hearing aid...
It's a little amusing, but I'm also embarking on a mission to quiet down Lil Red... not the combustion rattle (that's quiet enough), but the overall truck noise... Remember, this was a 5.7L gas truck originally, so it doesn't have a lot in the way of sound abatement. So, I'll be installing a muffler along with more padding (firewall pad, under-hood pad and a rubber mat for the bed). Everything is an echo chamber now.
Yeah buddy
Tain't lived till you have driven a big rig with a Detroit V12....The O'L Buzzin dozen...
A SWEET SOUND INDEED
Used to run Euclid SS40 3 axle scrapers. 1271 Detroit and 4 speed Alison, with open sided hood and 6in well pipe with a steel seat pan welded on top of it. Had 1/2 in of cotton padding in a vinyl covering. Always carry a spare set of cloths because when they blew a hydraulic line you were getting a bath.Quote:
Originally Posted by Robyn
Ahaaaa, the good old days!
Gotta love the smell of hot hydraulic oil eh ????
Especially with the smell of scalded flesh. And if you dont change cloths it will blister your skin.Quote:
Originally Posted by Robyn
Yeah buddy
Even the cold oil will likely give ya a nasty rash if it's not washed off....
Back when I was a young apprentice on a lube truck if we got an operator that couldn't park in the lineup correctly after several warnings we would dribble diesel on the seat cushion. They would have a red ass after a couple hours the next day.Quote:
Originally Posted by Robyn
HAAAAAAAAAAAAAAAAAAA....ROFLMAO
Yup...that will do it...
Felt confident about the head gasket R&R so we took about a 300 mile overnight road trip with Lil Red on Mon/Tue. No oil use, no coolant loss and no abnormal pressure buildup in the cooling system. :o
https://www.thedieselpage.com/images...Dash-85-aa.jpg
This was taken on I-90 about 60 miles east of Missoula Montana, headed west/home. The speed limit on I-90 here is 80-mph. The 3.42 gearing and 275/55R20 tires make for fairly tall gearing. The truck loves it. We crossed the continental divide on US-12 coming/going. Truck stays in OD with ~8-10 psi boost and ~1000 degrees EGT at 60-70 mph while climbing the grade (there are some corners). So far so good!
Edit: The JK 600+hp ECM race programming (did 632 on it's last dyno pull) was replaced recently with a Kennedy program that includes both a stock power/fuel economy setting plus a +100 horsepower switchable setting. In addition, John corrected the speedometer for the 3.42 differential gearing and tire size as part of his programming for me - thanks John. I haven't used the +100 hp setting yet. Wanted the new head gaskets and cup sealing to settle in a bit.
I don't know if you can see it in any of the prior images, but this engine is also running a Banks "Big Head" wastegate controller, which has a larger diaphragm than the stock one, and it includes an adjustable control rod - to control spring pre-load (thus boost pressure). Current rod adjustment produces 25-psi boost pressure during a brief full pedal run - still goes like a bat even with stock power. The truck delivered 22.13-mpg on the last fill-up (250.1 miles), which was a good part of this trip. Considering the speed...
Jim
Just an update...
The GMC now has about 6500 miles on it since the head gasket replacement. I bought the oil and filter for it a week or so ago, and will change it soon. This'll be the first oil change since the work. It's been such a relief to not have excessive pressure in the cooling system no matter how long or short the drive. We've driven the truck on several trips of a few hundred miles each - mostly this past winter when the roads were awful. The engine starts, runs and drives very well. Fuel economy on winter fuel has mostly been in the 18-mpg range on trips and high 16s-low 17s locally.
Lil Red only has about 1500 or so miles on it since the head gaskets. It too, runs very well without a hint of excessive cooling system pressure. I did notice a very minor fuel leak somewhere near the driver side fuel rail. I need to remove some stuff covering the area and then re-torque the fittings.
Update! It's finally here, about 13 months since the project began.
https://www.thedieselpageforums.com/...6&d=1655244034
https://www.thedieselpageforums.com/...5&d=1655244034
Go here to learn more: https://www.thedieselpage.com/duramaxdieselserviceguide.htm
If I can find it, I'll post a pic of the quote I received a year ago from our local GM dealership for just replacing the head gaskets - $6500. That didn't include injectors or much of anything else... other than head gaskets and head bolts. That was the biggest incentive to do the work ourselves (daughter and I). How hard could it be? In hindsight, it wasn't that bad, but going in - there were so many unknowns that it was a little scary. Now, not so much! Thanks to JK, Greg and others for tips, and for everyone's encouragement. Jim
Looks great Jim.
"Doing the exact same repair yourself would reduce the cost to a total of only about $3500. This is why more of us are finding the will to work on our out-of-warranty trucks. In the end, doing the work yourself will provide far more value and truck performance/longevity than you could expect by hiring someone else to work on your Duramax."
You got that spot on....
The quality of the "$10,000.00 job if done at the dealer is suspect IMHO....
Doing your own work certainly does add the fact that as the owner.....You care far more about the outcome of things rather than the guy who is only interested in beating the flat rate time...
The attention to details and taking a second look at the little things that might well come back to bite you if you don't deal with them properly......
I have not been closer than looking over the fender at a Dmax ....but certainly appreciate the work needed to gitterdone...
Good one....:D
Thanks Robyn.
My 2001 3500 is making pressure and have idle smoke when i haven't ATF'ed it in a while.
As much as i have been putting it off,i am going to have to start looking for tools and parts to do the head gaskets and injectors.
First step will be to add the new books to my library.
I was told that the injectors were done at one point,but there was no paper history of it.My assumption is that if they were changed the lines weren't.Plus there is a chance the injector tubes are causing the cooling system pressure.Is there a way to point to the gaskets or injector tubes?
Thanks
Quote:
Originally Posted by Yukon6.2
After having done two sets of head gaskets and re-sealed 16 injector cups, it's my opinion that the LB7 injector cups are rarely the problem with excessive pressure in the cooling system... Unless there's been work there in the recent past, and it wasn't done right.
Thermal cycles are, I believe, the biggest contributor to gasket failure... Time and starts... The gaskets simply wear out. Gasket replacement isn't that bad. The new Duramax Service Guide walks you through the complete process showing what tools, supplies and items you'll need, as well as showing you how to do each step. Lots of helpful tips and practical experience. I'll even give you my phone number if you need it - it's right there in the Service Guide. Both of these engines are running great... My GMC now has going on 8,000 miles since the gaskets and Lil Red about 4,000 miles. There have been no problems with either truck other than a couple of fuel leaks that were super easy to resolve. After far too long a time, it's so nice not seeing excessive pressure in the cooling system... Both trucks are dependable enough to drive across the country without worrying about the engines. ;)
The past 10,000 miles and 18 months have been pretty amazing. I lived with the excess pressure in the cooling system for several years prior to the head gasket replacement, which limited the usefulness of the truck. It had become a "local-only" truck. But, for the past 18 months+, I could drive it anywhere, and I have... including several 250 mile trips to see our daughter during the last 2 winters.
The cooling system over-pressure was eliminated by replacing the head gaskets. Now, you can squeeze the upper radiator hose right after driving the truck, or after sitting over night and not have a hard hose. Before, the radiator hose felt more like a kid's bike tire (really hard) when the engine was near operating temperature. In addition, there is no "swooosh" when opening the coolant surge tank cap when the engine has cooled. An over-pressure problem left the cooling system pressurized even after sitting overnight.
However, I do have an oozing coolant leak - the small 10mm coolant hose located behind the fan pulley assembly. I had installed a new hose, but used the same screw clamps that a local mechanic had installed during a water pump replacement some years ago. I really don't like screw clamps for engine coolant hoses, preferring the OE spring clamps used by GM. For the head gasket replacement in Lil Red, I was able to re-use all of the OE coolant hoses and OE clamps. Lil Red's LB7 hasn't leaked a drop since it got new head gaskets.
So, my advice... Learn how to remove/re-install the OE clamps. Your engine is better off with them. ;)