New engine for the family truckster!

[njsteve]

I just splurged $8 grand+ and bought a brand new engine from the military HUMVEE assembly line at AM/GEP (via Peninsular Diesel, who have a contract with them).

It's the upgraded 6.5. Not the Optimizer that GM sells over the counter...or used to as they recently discontinued the exact engine for my 1995 model but still offer the other years. This is the 2017 higher-er output military version with super heavy duty block, forged crank, rods, low compression (18 to 1 anodized, instead of 22 to 1 standard pistons) and upgraded cylinder heads. The lower compression pistons allow for much higher boost without causing much higher internal heat and strain.

I bought this 1995 GMC K2500 diesel Suburban brand new back in the Spring of '95. You may recall the fun I had when the headgaskets blew during the MCACN trip in 2013. The headgasket replacement lasted another three years and 15,000 miles but the recent oil analysis was showing some major lead and tin values in the oil - to the tune of 17 times the maximum recommended standard. Every time I'd talk to the oil analysis techs, they kept asking if this was from a running engine or an autopsy? When I told them it was running fine they asked if it had any oil pressure and whether it was making angry, loud, unnatural noises? In fact it has been sounding the same way for the past 22 years and has never been stronger!

And you know as well as I do that a great running engine is always a bad sign that catastrophe is just around the corner. I even towed the SD455 and 24' trailer with it last weekend and it ran flawlessly.

So obviously it was time to go big or stay home.



Here's the oil analysis:

[njsteve]

And here's the new engine. All 875 lbs on the stand.

[njsteve]

Here's the build thread over on the diesel website I hang out at. There is something of a cult following for guys who try to keep this 6.5 diesels on the road.

http://www.dieselplace.com/forum/63-gm-diesel-engines/21-6-5l-diesel-engine/549473-6-5-engine-just-blew-up-my-95-suburban-not-happy-camper-20.html

And yes, it's a Real Turbo-jet 396. :-)

[Xplantdad]

Cool!:biggthumpup:

[Tarrytown SS427s]

Nice old Suburban, and looks like you've kept it clean! I always wished they put the 6.6 into the GMT800 Suburbans.

[Tommy]

Here's the build thread over on the diesel website I hang out at. There is something of a cult following for guys who try to keep this 6.5 diesels on the road.


And yes, it's a Real Turbo-jet 396. :-)

6.5 owners like pain and punishment, I'm one too.. Just threw 3000 bucks at mine (again)...

Tommy

[njsteve]

What did it need? I've been tinkering with this one for over two decades now. Other than the headgasket glitch (a known problem) and relocating the PMD (injection pump brain) to behind the front bumper instead of on the 200+ degree engine, it has been a great truck.

I decided against rebuilding the existing engine because it already has the inherent stress cracks in the original heads between the valve seats (which GM declared to be not an issue in their TSBs), so I would have had to spend a couple thousand for some non-Chinese cast heads... and then new pistons for a thousand more...yada yada - til the cost approached a brand new engine that has all the old weaknesses designed out. That's not even considering that possibility that the block could have main web cracks. Certain batches of these blocks, mainly in the 1997 to 2000 range were machined too quickly after casting and were too green when assembled. The main webs crack right were the bolts go in and travel to the location where the oil squirters were drilled to spray the bottoms of the pistons.

So, in the event the block has no cracks, I already have several 6.5 guys wanting it.

[Tommy]

I had new injectors/glowplugs and glow plug relay installed as well as new Turbo and turbo master from Heaths Diesel (with hurricane wheel). Also bought Heaths improved water pump and new fan. I ditched the old crossover pipe and added the larger mandrel bent unit as well as a Diamond eye 4" exhaust. We found several oil leaks and spent some time and money sealing those up. Added a new starter from Heaths too and had to buy a new front starter brace as the last one was installed without the brace. last year I trashed the 4L80E so that was replaced with a new one.

My truck is a Behemoth, a 2000 model long wheel base crew cab 4wd dually with 4:10's and I was hooked the day i saw it. Unfortunately I was never a fan of the engine but the rest of the truck overrulled the engine. In case anyone is scratching their head, yes its a 2000 model. the 2500/3500 kept the 88-98 body till 2000.

Tommy

[njsteve]

You will like that Diamondeye exhaust and crossover. That was my Christmas present two years ago. The 6.5s really breathe with that setup. That factory crossover pipe is a horrible double wall design and 50% of them have a collapsed inner pipe at the bends. It reduces the flow from a 2" pipe to a 1/2" pipe.

I've been running the Heath maxi-torque chip and turbomaster manual boost adjuster for 6 years. My truck is an OBD1 so it uses the old fashioned PROM chip. Good stuff. I also have a delegated laptop that has the GMTD Scantech software on it so I can reset the pump when I install it on the new engine. Without that you have to go to the dealer and they usually had no idea whatsoever on how to work on these trucks (unless you find an oldtimer still working there) .

Never run a starter without a brace on these engines. Many a horror story of guys breaking the ear off the block from the starter loosening the two mounting bolts and then torqueing over without the brace in place.

Let's see a photo! My neighbor down the street has the exact same truck (but a 454) and it's black. Evil looking monster.

My first casualty so far has been the starter - the tiny terminal on the solenoid snapped off...and get this...the AC/Delco solenoid is discontinued and even an aftermarket version is $165!!!! But a brand new ACDelco (not reman) starter is $148 (rockauto). Ordered it yesterday.

[njsteve]

Oh, the joys of getting those last two upper bellhousing to engine bolts. There is no easy way to do it. They are double studs with all sorts of brackets coming off the studs. And not accessible from under the truck. I had to rip the remainder of the inch-thick, sound deadener pads (probably made of asbestos) off the firewall to even see the studs. That, of course is after I pulled the intake manifold, fuel/water separator, assorted non-moveable wiring harnesses, etc,. Luckily I borrowed my friend's ladder-creeper - a real life saver! I used a ratcheting, angled, closed end, 1/2" wrench for the nuts and 9/16" for the studs. - yeah this is a 1995 so they used SAE threaded transmission-to-engine bolts. Everything else on the engine is metric.

[njsteve]

Oh, and yes this was the extent of my family's assistance in this endeavor on this holiday weekend - laughing at me as I am devoured by the family truckster and photographing it for posterity. :-)

[earntaz]

Climbing into the engine bay like that is really getting into your work ... LoL TAZ :beers: :biggthumpup:

[njsteve]

I spoke too soon this morning. My wife was busy so my son actually helped me take the hood off the truck so the hoist would fit. Though I did have to wake him up at 11:00 AM to do it.

[njsteve]

We have lift off at noon E.S.T. today. Of course the new lift cylinder was at max extension with the rad support still 3/4" higher than the oil pan. I had to take the truck off the jack stands and use two floor jacks to lower it down as far as possible so I could get the engine over the front end. The boy actually assisted in pulling the cherry picker away from the truck. So he is now taking credit for pulling his first diesel engine.

[earntaz]

Extend the boom one or two notches ...

[njsteve]

In its present position, when level, the boom is the same length as the feet. I don't want to put it out any further than the feet will extend. Kind of a stupid design to allow the boom to extend two feet further than the legs. That's a 1,000 pound flip waiting to happen. When I tried to have the boom further out, I had to stand on the rear of the hoist to keep it from lifting. Very scary!

[Tommy]

that hoist has all it can handle in that pic. I imagine you were glad to get that engine on the ground !

Tommy

[earntaz]

Kind of a stupid design to allow the boom to extend two feet further than the legs. Exactly!!

[njsteve]

Yesterday I ripped out all the remaining busted, crumbling, plastic sound deadener panels shielding from the firewall and then pressure washed the engine compartment. Sure looks nice now.

I need to replace the motor mounts and I bought a new set of Napa mounts. Trying to access the nuts on the underside of the cross member does not look like a fun job. Anyone know any secrets to doing that job?

[njsteve]

I spent most of today disassembling the old engine and moving parts to the new engine. I was able to pull the water pump and cover off the old engine, move it to the right timing position and then transfer timing gear and injection pump (with the entire "spider" of fuel lines intact) to the new engine. I moved the injectors, installed new copper gaskets and torqued them down. I also installed the high output water pump on the new engine as it is going to the dual thermostat setup. I had to run out and buy a tube of the special anaerobic sealant. I applied it to the back section of the plate and used a thin paper gasket between the sealant layers. I also made my own reducer for the water pump fitting by drilling out the nipple and then inserting a screw in plug with the center drilled out to 3/8".

Today's casualty was the crank position sensor which of course, broke the mounting tab off when I tried to remove it. I already ordered a new AC/Delco one from Rockauto. Should be here Thursday.

[njsteve]

We have touchdown at 10:00 AM EST! And the wonderful wife gets credit for the assist as she helped hold the engine in place as it kept trying to twist out of flightpath as it touched down. The motor mount bolts just slid into place, too.

[Lynn]

Nice Steve. I really like the smooth sided pickups and Suburbans from the 90's.

Don't think you will regret this move.

[Chris KH2PM]

Nice upgrade. Those 2500 Suburbans are nice. I actually spotted one not too long ago going down the road.

I had a '94 Chevy Silverado K2500 6.5 turbodiesel. Bought it new and drove it about 70K miles over 6 years. Loved the smooth power and the sound. And it rode great too with that long wheelbase.

Later I bought a new 2001 GMC Yukon XL 2500 4x4 with the 496 and 4.10 gears. Now that was a towing beast!

[njsteve]

Nice truck!

[njsteve]

Got everything in, on, and back together working form 7:00 AM to 7:00 PM today. I left the inner fender off for leak checks, etc. The battery cables are still hanging (actually, the ends are soaking in baking soda and water to remove the trace of "battery crust" I found on them). I will try to start her up tomorrow. I have the laptop ready with the Scantech program for setting the injection pump.

[njsteve]

Well, after the usual BS of finding out that my brand new AC/Delco fuel filter/water separator leaks like a sieve out the bottom, and having to reinstall my formerly grungy old one, all went well.

I didn't remove the glow plugs and crank it for a while to prime the injectors, like most guys recommend. All I did was prime the non-leaking fuel filter assembly by jumping the fuel pump relay and verified there was no air in the system. I then turned the key and waited for the glow plug light to go out. Instantly running! no coughs, no hick-ups, no drama whatsoever! Amazing!

I then let it warm up to 185 degrees so i could use the Scantech on my laptop hooked to the OBD1 port and set the TDC on the injection pump. I was close to the factory installation spot but a hair off so the advance was giving a DTC-88 fault code. I had to then use the pair of bizarrely pretzel-shaped injection pump wrenches that I paid $90 for (and now am happy I did) in order to move the pump half a millimeter to the passenger side. It's a nearly impossibly feat given that all the injection pump steel lines are bolted down into brackets and the pump would barely budge. (imagine trying to remove that spider creature that locks on your face from the movie ALIEN and you can imagine how hard it is to move that pump). Oh, and by the way, the injection pump is located underneath the intake manifold.

I eventually budged it enough to reset the timing and clear to fault code.

That's when I noticed my original fuel filter canister was leaking. Ugh.

I replaced it with the new one again after checking all the fuel lines and replacing the clamps. And....it leaked even worse than before. So I removed it and tried to pull the filter out to see what was wrong. That is when I discovered that the brand new unit had its plastic collar so tightly torqued on that I had to put the thing in a vice and turn the housing with a pry bar. Once I finally got it unscrewed, that was when I learned that the idiots who assembled it, neglected to install the all important sealing O-ring for the lid. Luckily I had an extra filter laying around. I took the O-ring, installed it in the housing and hand tightened it. After the third reinstall, it finally worked. No leaks.

I then went for a ride to return some of the tools I borrowed from my buddy - truck jack stands, wobble sockets, 1-3/8" socket for the oil filter adapter, etc. The truck starts on the first crank of the key and runs very nicely.

There's a noticeable difference in power above 50 mph - really starts pulling and wants to go fast(er). I have the boost is limited to 9 psi for the time being I'll turn it up a little more after I put some miles on her. No leaks or drips at the moment. This weekend I'll put it up on my buddy's lift to retighten everything.

So in the end it took nine full days to get old engine out, transfer all the reusable parts to new engine, install new engine and get it running. I lost five pounds of weight in the process! That's better results than nine days of Crossfit.

Now I can drive the truck back to the gym again.

The next project is pulling the oil pan off the old engine and seeing whatsup with the bearings.

[Tommy]

congrats Steve. That was a big job. I hope that new engine gives many years of service. You are right, its hard to find anyone that can properly work on those trucks and equally hard to find anyone willing to work on them. I am curious why you have the aftermarket air filter though Steve. Have you seen the temps of the air you are drawing into the turbo with that setup? The air temp under acceleration will go above 250 degrees. Put the stock unit back on and the temps immediately go back to outside air temp.

Tommy

[njsteve]

That's not what I run. That is just the air filter itself stuck on there to keep the critters out of the turbo as the truck sat overnight.

The entire filter fits inside the later model K47 air filter box which routes air from inside the fender. Here is the actual setup in place. I modified a piece of ABS toilet plumbing pipe from Home Depot. It cost all of $3 to replace the unobtainable and uber-fragile, thin-walled ABS duct piece that is unique to the 6.5 diesels used from 96 to 99. All I had to do was heat it with a propane torch and squeeze it in a vise until it became an oval shape that matched to rubber bellows that connects to the turbo. The round end of the tube fit tightly inside the K47 filter element that you saw in my previous photos.

[Tommy]

very cool!


Tommy

[njsteve]

Flows like a good running toilet should flow!

[SuperNovaSS]

Well done Steve! I have been watching from the shadows and am always impressed by ingenuity and determination.


Jason

[David Billingsley]

Most impressive, looks like the mother of all engine swaps, enjoyed your post Steve, job well done.

[njsteve]

Thank you! This was quite the process. I have always been intimidated by modern stuff so this was something of a leap of faith, hoping it would work when the process was completed. and this engine is really heavy - I'd compare it to a fully dressed iron 426 Hemi in weight. And the fact that most mechanics have long forgotten how to work on and tune the 6.5 diesels - that was incentive to learn it all myself - combined with the unimaginable $$$$ cost of 9 days of labor doing the swap if I had a truck garage do it.

In the end, I don't know what I was so concerned about given that all the computerized stuff just runs itself once it is plugged back in. That was one of the reasons I tried to retain as much of the known running components on the new engine - old injection pump, injectors, wiring etc. I didn't want too many variables throwing a wrench in the process. I did end up replacing the Fuel separator/filter, starter, and radiator, with AC/Delco parts. I also replaced the engine mounts (the GM ones are no longer available) - though the diesel guys warned me that all the mount manufacturers superceded the mount part numbers to one unit that fits smallblocks, big blocks and the diesel - when the diesel had a special much heavier duty rubber used. As luck would have it I found one NOS GM diesel mount on ebay...one day after setting the motor back in the truck. So we will see how long the NAPA mounts last. AT least I have a spare in case one fails.

Now the truck is ready for cruising again!

[The Boss]

Necessity is the mother of invention!

Nice job as usual Steve.

[njsteve]

Thanks!

I was just out in the driveway on the creeper, checking the underside - still all dry - even the oil filter adapter!

I then spent two hours picking up all my tools and cleaning the garage.

I was able to get the old engine onto the engine stand and turned over so all the antifreeze could pour out all at once into the catch pans. I'll pull the oil pan in the next day or so to start inspecting it.

[Ryan1969Chevelle]

Very cool!!

Nice truckster.

Ryan

[RPOLS3]

Impressive - nice write up as usual.

[daverd]

Did you move the injector power control unit form indeed the intake manifold?
With a new cool plate?

[njsteve]

The PMD (Pump Mounted Driver) is the little computer box that was originally mounted to the side of the injection pump under the intake. The designers thought it would be a great idea to have the super-hot running circuitry inside it get cooled by the diesel fuel running through the pump when the engine was running...only they didn't think about what happens when you shut the engine off and the heatsink effect fries the PMD.

I relocated it to behind the front bumper about ten years ago and never had a problem since. The truck went through three injection pumps when new. I bought it new in Florida and the first PMD fried five miles from the dealership the day I bought the truck! Back then GM refused to acknowledge the design defect and would replace the entire thousand dollar injection pump (with PMD attached) instead of just swapping out the PMD. GM eventually admitted the problem and extended the warranty on the pumps to 10 years or 100,000 miles. But they still would replace the entire pump instead of the PMD.

Here's a photo of the original PMD still on my injection pump. I bypassed it with an aftermarket four-foot long harness extension that reaches to the back of the front bumper behind the license plate brackets. It is mounted on a large heat sink in the protected airflow of the oil cooler duct holes in the bumper. I finally removed this old PMD from the pump last week and am keeping it as a spare - you always carry a couple spares in the tool box when you have a 6.5 diesel.

Kind of like the Mopar guys always carry a couple extra ballast resistors in the glove box for the old Mopar ignition systems.

[Xplantdad]

Steve, One of my jobs while working at Hardin Olds/Honda/DeLorean was to drive the numerous diesel injection pumps to the rebuilder on a daily basis from Anaheim to Ports of Call, Long Beach area...I put over 100,000 miles on a new Delta 88 in one year...taking them back and forth. I think this was 1979, maybe 1980.


That's what they get for converting a gas 350 to diesel...and not putting a water separator under the hood :)


Great job!

[njsteve]

Here are the necropsy photos. We'll start with the rod bearings. Looks like the oil analysis was spot on based on the flaking of the outer bearing material and the wear in the second layer.

[njsteve]

and next, the mains:

[njsteve]

The oil pan was pristine. nothing whatsoever in the sump area. You are looking at an empty pan - not one full of oil - it's that clean!

[njsteve]

And now for the bad news...these block were notorious for developing cracks in the main web area emanating from the main bearing cap bolt holes and the sharp transition where it was machined for the mating surface with the main cap. A lot of guys consider this normal and rebuild the blocks using some type of main web girdle.

So it looks like my gamble paid off of buying a new AM/GEP engine off the assembly line instead of waiting to see if my engine was rebuildable. You can't buy the AM/GEP block outright (despite the many chinese knockoffs being advertised on ebay and elsewhere as "AM/GEP updated blocks"). The only way to get it is to buy a brand new engine off the assembly line or buy a used HUMVEE takeout from a military salvager - which you would then have to take apart anyway to verify its condition..

The easy way to find the cracks is to spray the area with brake clean and then have a camera ready as you observe it evaporate. The crack will weep oil out at the last phase of evaporation and be visible for several seconds.

[Crush]

Wow great detail

[Ryan1969Chevelle]

Boat anchor:-(

A team of engineers should be a shamed:-(

Ryan

[njsteve]

I believe they traced the cracking problem to the fact that they were machining the engine blocks while they were still too "green" and the tolerances were changing after the block had some seasoning to it. Hence the cracks in the corners where they join with the main caps, and the main bolt hole cracks. Remember that these are low rpm engines - under 4,000 rpm max.

Back then they were making these engines as fast as they could churn them out, and selling them as fast as they made them. When the military HUMVEES went to the 6.5, AM General bought the rights to the engine and completely redesigned it to get all the stupid issues solved - cracking blocks, cracking heads, bad coolant flow to cylinder 7 and 8 (exactly where my headgasket blew out in 2103).

At least I can pride myself on the fact that the inside of the engine was spotless - no sludge, grunge, or caramelized residue anywhere...and for a diesel no less! I guess that's what 22 years of oil changes at 3,000 miles can do. All I ever used was the Rotella 15W40 and AC/Delco or Napa Gold filters.

[COPO]

Great thread. Well done.

[njsteve]

BTW, let this be a lesson to not leave your tools out when you're done with a job...

...The wife saw the cherry picker in the driveway and got an idea to use it to pull out some tree stumps. It actually worked pretty darn quick. Kind of like pulling a tooth. Took maybe 10 minutes once it was set up, instead of 4 hours the last time she made me chop one out of the ground with a pick axe.

[Tommy]

resourceful !


Tommy

[PxTx]

I remember doing that at my 1st home. My neighbors were watching and my wife and I got a round of applause when the stump was freed!

Option B, may have been to tie the Suburban to it and pull it out in low gear. Option A seems much safer!

[njsteve]

Yeah option B is not an option after the number of youtube videos I've seen of things flying into the back of the pull vehicle when they finally let loose. That, and the fact that we had a downpour last night which would have turned the front yard into a mudbog-a-palooza-fest for all the neighbors to enjoy.

[njsteve]

Finished the autopsy today on the old engine. Here's some photos.

Pulled the heads off. Some of the chambers have the normal cracks between the valves. GM considered this "normal" wear in their TSB.

[njsteve]

The valve covers were immaculate. (The black painted one is the NOS cover replaced during the headgasket job in 2013)

Camshaft and lifters looked nice - normal wear.

Looks like the cam bearings were showing copper on all of them.

[njsteve]

The upper halves of the main bearings all were flaking like the lower halves.

You can see the difference in the main cap mating area where the crack goes through the bolt hole.

Looks like most of this stuff is going to the scrapman in the next few weeks. The old mill had a good life. Gonna be sad to see the big ol' hunk of iron go.

[earntaz]

Looks to e FUBAR to me ... TAZ

[njsteve]

Yeah. I guess running 22 to 1 compression for 22 years is a bit stressful for the too-thin main web area. Seems like the pistons were trying to shove the crankshaft out the bottom of the block. The new blocks were redesigned to handle this stress (and made out of a different iron formula, too.

[earntaz]

I remember when my uncle bought a new Olds with a diesel -- they sold him a separate "insurance" policy for the engine ... I asked him why he thought that was necessary? Yup -- less than a year later it spit the crank out the bottom of the motor ... TAZ

He sold that thing ...

[njsteve]

Just for comparison sake I'd thought I'd post a good oil analysis.

Just got the oil analysis today for my 1989 John Deere 185 riding mower. I bought it used in 1990 and have been mowing our couple of acres for over two and a half decades since. I tricked both kids into learning how to drive by making them mow the lawn for years with this thing. They then proceeded to break everything breakable on the tractor but it stills keeps going. For the longest time I thought my daughter had a kickback scheme going with the local JD dealer. She'd break something - like the hub out of the wheel and I would bring it into the dealer and the parts guy would usually say "I have never seen one of those break before." And then I'd pay a ton for a new wheel, bracket, pulley, etc. I have since resorted to ebay for a lot of used parts since the dealer prices have gotten insane.

I change the oil every year or two whether it needs it or not. It runs a Kawasaki engine. Looks like Blackstone likes this sample from their comments. Interesting how they noted a high silicon result from possible dirty air filter. Turns out the air filter is clean but there is a big gap between the air cleaner duct and the carb inlet that is letting a bunch of unfiltered (dusty) air get through. Time to get out the duct tape and seal that up.

[njsteve]

Just got back from the vacation trip to Lake Placid. Total mileage on the new engine is around 1,200 miles. The highway mileage on the uphill route to upstate NY was 17.0 mpg. The "city" fuel mileage for the 200 miles around town while we were up there, was 14.5 mpg.

I changed the oil the last night when we got home and saved a sample to send in for baseline analysis. Magnetic drain plug was clean.

I just got back from filling the tank to the top. The fully loaded return trip (downhill from 2,000 foot elevation) got us 18.31 mpg highway. A new record! Not bad for a 8600 lb GVW Suburban with 4.10 gears and Yokohama Geolander 265/75x16 tires

The truck ran flawlessly. No noises, glitches, twitches, drips, etc. I am very pleased with the results and the new low compression AM/GEP engine. Very smooth running at speed.

[TMagda]

I was just thinking this morning "NJSteve has been very quiet". I was looking in the wrong place. I go straight to the Pontiac section.

[njsteve]

LOL. There was no GMC section so I threw it here.