Well, here is the latest aftermath of a poorly designed underbuilt engine... Bent rod, broken crank, busted main webs, and a couple of broken pistons. It's hard to tell which happened first, but I'd venture to guess crank or main webs were first and the rest followed...
Bent Rod:
http://img.photobucket.com/albums/v622/dieseldummy/FXCD0004.jpg
Broken Crankshaft:
http://img.photobucket.com/albums/v622/dieseldummy/FXCD0002.jpg
Main Web:
http://img.photobucket.com/albums/v622/dieseldummy/FXCD0001.jpg
Broken Piston #1:
http://img.photobucket.com/albums/v622/dieseldummy/FXCD0006.jpg
Broken Piston #2:
http://img.photobucket.com/albums/v622/dieseldummy/FXCD0007.jpg
A couple of the pics are kind of crappy, but ya get the idea... This is my reason behind my advice to not buy a 6.2/6.5 diesel...

Hmm.

Although these are interesting pictures, I am sure I could grab some parts out of a failed Indy car and see the same thing and state that all Indy cars are junk. Although people could say that I am biased because I own two 6.5TDs and cannot be objective, it seems to me that any engine that is operated beyond its design tolerances would show similar catastrophic failure. What were you doing when this failure occurred?

GM/AM General has made well over 1M 6.5TD units, if I am not mistaken. AM General continues to make them today, and I believe they are being shipped to Iraq and other places where they are endlessly tortured by Military demands no less. If this kind of failure were truly commonplace, then one would think that a PR disaster on the order of the Firestone 500 would be all over the news. If I were a soldier and knew of any such things being commonplace, I would certainly be making a stink before me and 5 buddies and a couple of tons of gear strap in for a mechanical failure in enemy territory!

I think that a statistical analysis of 6.2/6.5 would show that this kind of failure is not very common. I'd like to see some more data before I panic and sell my Tahoe and Suburban. I'm NOT convinced.

Sincerely,

Rob :)

Rob,
I will tell you what I base my recommendation against the 6.5 on. My pickup has had 3 catastrophic engine failures now, and continues to overheat even after all the cooling upgrades. A good friends first pickup: '91 chevy w/6.2 and a banks kit was rebuilt that lucky 3 times as well, just before #4 came about it was totaled in a wreck. His second pickup was a '95 it had a new GM engine in it when he got it. Besides the overheating problems and the common PMD related stalling it was ok if ya didn't want to go anywhere very fast. Current pickup is a '96 it has been rebuilt twice. The reason for the second was a broken crank and main web failure. You may think it is a fluke, but I see it as a conincedence that at some point 3 out of 3 pickups I've been around and helped work on have had a major engine failure at somepoint around 115K-150K. Not what I'd call good statistics...

The military connection that you mention is probably a result of GM/AM-GENERAL giving the military a smokin' good deal on an engine that has been around for years that parts are very available for. The 6.5 costs 2/3 and in some cases 1/2 of what a Duramax or 5.9 cummins does, when equipment is sent into a hostile zone where there is a strong possibility that it wont survive I'm sure that the best/most expensive isn't sent in, but the mediocre/cheap is.

I didn't post saying that everyone should get rid of thier 6.5's. I did it with the intent to share my latest experience with everyone and say that this type of thing has become too comonplace in my life lately so I won't own a 6.5 again and won't reccomend that anyone purchase one.

Justin

Just maybe you're asking more than your 6.5's are willing to give, they were never built as a heavy hauler and that is known when they come out of the factory with a sticker under the hood advertising 195 HP @ the flywheel, i was asking too much and mine gave me what i deserved, but it was fun while it lasted. Now we're building it to perform the right way and i can hardly wait to smoke some D'max, P'stroke & Cummins butt!!! (after the break in of course).

BTW, sorry about your loss.

Oh ya everyone, don't follow my mods!!! YOU WILL BLOW IT UP!!!

Justin,

I am sad to hear of your losses. I am even surprised that you and your friend continued to fix the trucks when they continued to fail time and time again.

It is still difficult to say that the failures are commonplace, given the lack of statistical data. Three engine failures in a row for one person is still anecdotal data, however bad the personal experience.

Do others think that 6.5TD is an inherently bad design or product? Should we all be saving up for something more robust?

I agree that contracts are awarded based on overall costs. However, it seems contradictory to train 5-6 Army Rangers for a Spec-Ops mission and then knowingly sending them out in a cut-rate HMMWV for them all to die due to mechanical failure. The overall costs would be much higher. According to AM General, there are more than 175,000 HMMWVs that have been produced. When they were tested, they tested the prototypes at 600,000 miles. Most surely we would have heard about multiple, common catastrophic failures by now?

Again, I am sad to hear of your loss, and hope that you can find a suitable vehicle that is sturdier. Perhaps you should be looking at a medium duty truck if the 6.5 is an unsuitable powerplant for your application.

Sincerely,

Rob :)



According to the AM General site (http://www.amgeneral.com/vehicles_hmmwv_background.php), "AM General became one of three contenders that were awarded an Army contract for the design and construction of 11 prototype HMMWVs (six weapons carriers and five utility vehicles). The other firms were Chrysler Defense and Teledyne Continental.

Overall, HMMWVs were tested for more than 600,000 miles over rugged courses simulating worldwide off-road conditions in combat environments. They were driven over rocky hills, through deep sand and mud, in water up to 60 inches deep, in desert heat and Arctic cold.

Complicated production proposals were required. Winning the contract was based on a combination of the most technically qualified and most cost-effective five-year production bid.

Contract Awarded

In March 1983, AM General was awarded the initial production contract for 2,334 HMMWVs. This was the first increment of a five-year contract for nearly 55,000 HMMWVs. These were produced in 15 different configurations over the term of the contract. Of these vehicles, 39,000 were for the U.S. Army and the remainder was divided between the Marine Corps, U.S. Air Force and Navy.

Production began at AM General's Mishawaka, Indiana plant in the fall of 1984 and the first deliveries were made early in 1985. The total production by mid-1991 was more than 72,000 vehicles including international sales.

Follow-on multi-year contract awards called for more than 33,000 vehicles. By March 1995 approximately 100,000 HMMWVs had been built. An additional 20,000 units were ordered by more than 40 international governments since 1991. To date, more than 175,000 units have been produced.

During late 2000, AM General was awarded another production contract for 2,962 trucks in the M998A2 series. The contract contained six single-year options running to FY07. At the time the contract was awarded, it was stated that 31,474 vehicles were to be purchased."

CR,

Maybe I ask too much, maybe you do too, or maybe our 6.5's just don't give us what they should. :lol: I don't know the answer and quit frankly I don't care at this point.

:rant: I have given the 6.5 more credit than most have had to. The first time it fails the natural reaction is to blame the previous owner for lack of maintinance and fix it "right". The second time it fails there is much cursing, alot of number crunching and in the end it is determined that there has been way too much money invested to get out from under it for a resonable loss so it is just merely "fixed" this time. The third time is when the mental break down occurs. There are many swear words and verbal threats used against the pickup. Vows are made to never mess with the offending engine again. There are promises that it will never be driven again, under current ownership, with the offending type of engine in it. Begrudingly, and for curiosities sake, the engine is torn down to locate the problem to see if it can be fixed so the vehicle doesn't have to be sold for parts. After 1.5 weeks enough anger has passed so the subject can be brought up on a discussion board to share what has happened, the conclusions that have been made in my mind, and maybe shake up the ordinary atmosphere with a not so frequent problem.

Rob,

I'm not here to argue with you about whether the 6.2/6.5 series of engine is worth having or not. I'm glad that you are happy with your rigs and I hope you never have to experience what I have with them. I have spoken my piece and so have you. I'll leave it at that.

Thanks for the thoughts on my behalf, but they really aren't nessecary. If anyone knows where to find a crack free 6.2/6.5 block or maybe a junk yard take out engine for a reasonable price let me know...:help:

Justin

I agree that contracts are awarded based on overall costs. However, it seems contradictory to train 5-6 Army Rangers for a Spec-Ops mission and then knowingly sending them out in a cut-rate HMMWV for them all to die due to mechanical failure. The overall costs would be much higher.

I totally agree. and being in those situations, it was never on our minds. we knew it was a dependable, hard working powertrain. :cool:

What are you using your rig for? We have lots of folks here on this board that have boasted long mileage on their engines, but usages vary. Some have endured what you have talked about here, and other's of us, have dodged the bullet.

Now, if you have the boost jacked up to 25# and pouring in more fuel than the piston can endure, towing 80,000lbs up a 10% grade for 18 miles . . . then, well, it's comin' over the horizon. But if it's your daily driver/stock okay, you've got some real gripes!

What preceeded these failures anyway?

It would be helpful, Justin, if you would post any mods, incl turbo type and Boost levels....................

Fer instance - I run 20psi on occasion in winter temps, for R&D.

On a recent 20psi run, the direct clutch sprag in my built T400 split in half, a common failure seen in 454 drag vehicles using the same trans.

Reckon I shouldda NOT been floggin' my ole 8500lb Bud draft horse, but I couldn't resist.

I have seen way too many people get into a diesel and drive the snot out of it and then when it gives them problems they point their finger at the manufacturer for a lousy product. Some people seem to think you can get in these things and get on em before the starter has even stopped spinning and then rev the snot out of them like a hot 327 and wonder what went wrong. I am not saying that is the case here, don't get me wrong. GM did fall short in some areas for sure, but with a set of guages and proper warm ups, and driving habits (eg: most truck drivers cringe if their tach gets anywhere near 2000 rpm!), I think a 6.5 is a good engine as long as you don't ask too much of it. :blahblah: :lol:

Justin - Yes. More Details.

jd - You ARE using the 34 Element Sprag, aren't you?

Just all the factory HD dump truck stuff, Billy - built it stock so would be easy to repair in any small town

Sorry for leaving out details, I can barely type one thought at a time...

This engine was stock compression, might have had the "topped" Mahle pistons in it, nobody could tell me what was really ordered and at the time it really wasn't too important. Intercooler has been there since I first got the pickup, all the cooling mods have been done, fuel was maxed out with a DB2-4911 pump, Holset HY-35 turbo was making a max of 22 lbs of boost under loaded situations. The pickup was used for a daily driver to and from work for a total of 30 miles each day. In addition to that it got the typical "farm" pickup duties of hauling bales here, hauling cattle there, toteing this trailer near, pulling that trailer far...

I had problems when stock, problems when at 18:1, and problems now. Like CR always says: Don't follow my mods or you'll blow it up. I suppose I was asking for it by expecting more than stock performance out of it... Just for the record I pluged it in during the winter whenever possible, change the oil every 3000 miles, let it cool down and warm up whenever starting or stoping it, I watch guages like a hawk as well. That is part of the reason I get so worked up over this when I treated it the best I could and it dies, then I watch most of my friends and family drive the hell out of their stuff and never have a problem with it.

JD, To bad to hear about the tranny, do I hear a mean 6 cylinder in your future finally?:ro)

Added on edit:
The bright spot of the whole ordeal it the heads are still perfect as far as I can tell and don't have any of the hairline crack coming from the valve seats or the big cracks between the valves.

Well i'll be having similiar mods but with the new high strength hummer block and splayed mains, new crank, cam, etc, basically a short block with 18:1's and splayed mains and balanced, according to DAS they have had no problems with this setup and i hope i'm not going to be the first.

OK I have been reading some post and am kindof discusted. First of all guys we are talking about an engine that has been around and basically unchanged for 12+ years!! You can't expect an engine with that old of a design to perform like a new truck. Back when this engine was made no one would have thought of turning the boost up or putting a computer chip in. Remember there was no such a thing as diesel performance when these engines first came out! They were never designed to take the abuse we give them today! Mine on the other hand has seved me well for 189,000 miles. I run 20# boost and sometimes more when pulling a trailer. I have reved mine past 4500 several times! With that said my truck will pull just as good as my buddies 2001 cummins. His is stock with an auto tranny and with the same load behind both trucks and on the same hill in the same time of year I actually held a higher speed than his! I have yet to see a case where a stock 6.5L pulling the max recomended load with the proper maintance and guages has had a catostrophic failure. So to me that says these are some damn good engines! :rant:

I would like to address your engine failure: Your crank broke, bent the rod, broke the pistons and broke the block, end of story. What caused the crank to break, could be a combination of a lot of things, including excessive bearing clearance on number 1 main bearing, bad balancer, etc. Have I seen other broken cranks? Yes, and usually at the same place and the block is usually destroyed because of it. Have any of my 6.2/6.5's ever suffered a broken crank? NO, could just be luck of the draw, who knows. Have I grenaded 6.2's and 6.5's? Yes, but I too was asking a lot out of my engines. By the way, my last 18:1 6.5 was running great when I sold it. Are the other engines bullet proof, Powerstroke and Cummins? No! I have witnessed numerous scored cylinder walls on cummins engines and many cracked pistons on powerstrokes, they just don't seem to break cranks. How about the #53 block on the 99 and 2000 era cummins, that seem to like to crack at about 101,000 miles. Bottom line is all of these engines are mechanical parts, some will last longer than others, some will have bad failures and some just won't wear out. Bottom line is, sorry that your engine failed, more than once, but you are no where near stock, so you have exceeded the design of the engine by leaps and bounds and have found what it takes to break it. In my opinion, 22 psi of boost on a stock compression ratio 6.5 is asking for failure, just like adding 55 lbs of boost to a cummins will without doubt blow the head gaskets.:(

22 psi on the manifold with 21.3 cr would have put the cylinder pressure over the threashold and onto the pavement. There was a recent calculation of pressure and CR but I think the person who posted it stopped at 18 psi. :D

Hey, I went higher than that....
http://dieselplace.com/forum/showthread.php?t=33074

The balancer on this engine was in ok shape, it wasn't great, but could have been way worse. Needless to say the outer ring hadn't sliped from the inner one. I was always under the impression that the head gaskets would be the parts to fail under high cylinder pressures, not the crank and block.

I guess I wasn't aware that posting this would seem to offend so many of you. I never said that the 6.5 is the scourge of the universe, I also never said that the other makes don't have problems. It has been my experience that the 6.5 has far greater problems than the Powerstroke, Cummins, or Duramax... Combined... A HEAVILY MODIFIED 6.5 might, stress MIGHT, keep up with a newer diesel!! Even if it does it will most likely have some major problem result from doing it. A LIGHTLY modified diesel of any other make will walk all over any 6.5 and not have any problem doing it.

I shall bid you farewell now. I see it has been pointless in trying to have a disscussion here. I personally am moving on, I gave the 6.5 every chance to prove it in my eyes and it failed... My next rig will have a Cummins or Duramax under the hood and I feel pretty confident it will fit the bill.

Edited for content, it's been a bad week.

Dear DieselDummy,

I am not in the least disturbed or angry by what you have said.

The fact of it is, the 6.5 was designed in the late 80s/early 90s as a turbo-charged indirect injection diesel. Its stock form targeted HP ratings of 180-195HP, and torque ratings of 360-400 ft-lbs during the 94-99 production years. The stock boost was maxxed at about 7 psi. There are many examples of trucks with 400K+ miles in the factory configuration without a breakdown.

My point is, it's a lot of fun to boost the 6.5 to achieve greater performance, but what many on this forum realize is that if you run 3x+ max factory boost and do other performance enhancements, then you significantly exceed the design parameters and it is not surprising that the engine will fail sooner and sometimes catastrophically. While I don't believe that I or anyone else wishes you or your equipment ill, I think most of the posts have stressed that they realize that operating well above the maximum stated design and build parameters of the engine can have negative consequences.

If you were doing regular maintenance on a completely stock powertrain, and experienced your three failures, then it would be more understandable that there may be something wrong with the inherent design and construction of the 6.5.

I think that you started with the phrase: "Well, here is the latest aftermath of a poorly designed underbuilt engine..." "... This is my reason behind my advice to not buy a 6.2/6.5 diesel..."

This may be what most people are reacting negatively to, at least in tone. The general consensus is that the 6.5 is not a poorly designed underbuilt engine. It is, however, a more dated design and construction that requires the user to take this into account.

It is quite clear that the 6.5 was ever designed to get 600 ft-lbs stock and up to 1000+ ft-lbs in 'racing' mode the way the newer direct-injection engines are, so you are completely correct that it "can't keep up", but it wasn't really designed to, so I don't blame the designers back in '89 for this difference.

Anyway, I hope you don't take offense. I realize that you must be really upset that a new engine will cost thousands to replace. I hope you find something that meets your needs.

All the best to you.

Sincerely,

Rob :)