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View Full Version : WHY BUY A 6.5



bertram31
08-30-2005, 00:06
I am brand new to this website and I have learned to research before I buy. I am considering a 96 6.5 Suburban 2500 4wd. 113K miles and is stock. Cannot confirm prior maintenance history. But what I have read thus far is even with great maintenance, one owner vehicles, issues with cracked block, PMDs, cooling, exhaust upgrades, and the list goes on. What is the ADVANTAGE of owning a 6.5. They appear to be plagued with signficant engineering flaws. I am seriously considering diesel due to longevity but now have my doubts. Any candid info you can provide will be most appreciated. Thanx. r/

DA BIG ONE
08-30-2005, 01:04
Originally posted by bertram31:
I am brand new to this website and I have learned to research before I buy. I am considering a 96 6.5 Suburban 2500 4wd. 113K miles and is stock. Cannot confirm prior maintenance history. But what I have read thus far is even with great maintenance, one owner vehicles, issues with cracked block, PMDs, cooling, exhaust upgrades, and the list goes on. What is the ADVANTAGE of owning a 6.5. They appear to be plagued with signficant engineering flaws. I am seriously considering diesel due to longevity but now have my doubts. Any candid info you can provide will be most appreciated. Thanx. r/ 99 2500/3500 series is about the best you can get IMHO.

bertram31
08-30-2005, 01:26
99 model out of my current price range. What issues if any on the 96 model. What I understand thus far is the 99 has the HO cooling. What other advantages to the 99 over the 96. Thanx. B31

trbankii
08-30-2005, 03:05
The thing to remember is that you always hear most about the complaints. The people without complaints aren't posting all sorts of messages about "another trip cross-state without any problems" if you know what I mean. You visit the Ford and Dodge sites and you see just as many complaints, questions, problems, etc.

Not saying that there aren't possible problems, just don't take it as all doom and gloom.

Just my $0.02 to keep it in perspective.

markrinker
08-30-2005, 03:07
- 99 had updated factory ECM programming that delivered better performance than the 96.

- Block failures were lower due to better casting designs.

The factory 6.5 package can be 're-engineered' to give reliable and powerful service, but does require some basic diesel knowledge and willingness by its owner to overcome some engineering shortfalls - most notably in the areas of cooling, boost control, and electrical system maintenance.

The expected lifespan of a good 6.5 block and crank is hundreds of thousands of miles - much longer than any 5.7L or 6.0L gasser is expected to last. You can find a nice return on your investment over buying new at todays high prices. Also, the older 6.5s are selling cheap because of their maintenance (unwarranted? Not sure...) reputation.

Do you have a good source of new and used GM parts and service in Guam, or would you do most service yourself?

Its been said that coming here to the DP to ask if you should buy a 6.5 is like walking into a bar to ask if you should have a beer. Understand that all of us have 'picked our poison' and generally like how it tastes!

Good luck with your decision.

Cowracer
08-30-2005, 03:49
But to answer the root question of WHY?

They are cheap.

They ARE reliable (given proper care and feeding)

They are easy to work on.

Parts are inexpensive ($45 for an injector vs. $250 for a D-max or P-Stroke)

Rock Solid trannies.

Decent fuel economy (20's in a full size 1/2 ton is not uncommon)

Comfortable ride.

Drives well (not like a wandering ford)

Body will not shake to pieces (like a Dodge)

Most are under the curve for depreciation. Meaning that all the "gloom and doom' you hear about how messed up these engines are drove prices below the expected market value.

Most people shied away from them becase of the 5.7l diesel fiasco. The 6.5s are not 'converted gas motors' like the 5.7s were.

The fore-runner of the 6.5 was the 6.2, which everyone acknowledges as a dead-nuts reliable motor.

They share the same basic design. The only real problems are poor design of the early electronic injector pump. Most have been replaced with updated designs (easy to verify) and FSD problems. The FSD thing CAN be dealt with easily. Pre-97 had cooling problems IF you whipped the crap out of them (i.e. towing heavy loads in the mountains) They changed they design in 97, and the parts can be retro-fitted on to pre 97 models

As far as cracked blocks. I bet the percentage of motors that have (or will) cracked blocks is under 1/10th of 1 percent of the total population.

Buy a 6.5, Take some of the savings over a comperable ford or dodge and fix the fsd thing. Add a few upgrades for reliability and power, and dont sweat it.

Its really a good motor.

Tim

20050627|3|008327|000043|65.183.99.20
08-30-2005, 04:21
I wanted an Auto. Ford and Dodge do not have a auto tranny that is anywhere near as good as the GM 4l80E.

I test drove all three brands and the GM is the only one I was comfortable in. They may not stand up as well under severe duty, but I'm not giving it severe duty.

Aryeh Levy
08-30-2005, 04:42
I've heard people post here that most 6.5 heads will have cracks. The new GEP blocks made by hummer add back Nickel and i think chromium that GM origionlly took out to save $.

These engines are not made for towing heavy loads.

Don't get an early engine or you won't be able to tow without overheating. I got a 1998, and drove with the brake on to see if it would take it. The coolant temp rose to 240, but it took it in stride. Personally I wish I had gotten a 7.3L Powerstroke.

My 1998 3500 gets 12 mpg. That's the same Mpg as my wife's dad's 1994 2500 GASSER.
I have 4.10 gears

If you're buying a truck for looks, get numerically lower gearing. You wont be able to drive highway speeds without terrible economy. Some people with 6.5's get 17 with 4.10 gears, some like me get 12. It seems strange, and maybe due to differences in balancing (pistons weigh same or different) vibration in engine, and transmissions.

If you buy a 6.5, dont buy quick. Take it to a good mechanic, have them take off the oil pan and examine for cracked block, compression test all 8 cylinders, dont buy one unless you know that the antifreeze has been changed every 50k miles on...
Make sure you get a competent mechanic to measure the front and rear rotors - they tend to wear out.
People dont mention, but the late model, 1998 and 1999 trucks have lower compression ratio allowing for moe power increases (boost and fuel) without a rebuild.
also test they hydroboost unit for operation.
If your truck has no catalitic converter, and it's legal in your area, GOOD. I had to pay $700 to get one fron a GM dealer. :-/
Oh yeah, the headlights are VERY dim compared to ford or dodge (you can fix it for ~200 in bulbs and wiring from kennedy diesel)
If you find cracks in the block, offer much less, and put a cummins 12valve 4bt. i've heard of a few people doing that. its a heavier engine, but it's much stronger. That way you get the chevy truck, but the cummins engine

It's not too powerful.

But it's very quiet for a truck diesel
You can convert it to run on vegetable oil without worrying about fouling the engine too much or blowing injectors (they're pretty cheap) (prechamber design is good for that)
it's pretty easy to do all the routine maintenance
The 4l80E is a rock solid transmission in stock trim with a stock engine.
The Gm 4 turbo is great too, i know some rx-7 guys who use that turbo for their cars, running 20 lbs boost - it's got great pickup and go for stop and go driving

The cab style is very comfortable if you get a silverado (i love my power lumbar support)
There are 3 or 4 things on this truck that go out regularly

Oil pressure switch (Fix it by running the lift pump operations off a relay, relay switched by OPS)
FSD (helped a lot by remote mounting a new one somewhere cooler)
lift pump (once about 100k miles probably)
Injection pump (about 80k miles average no maintenance service) $1500 to replace w/ a rebuilt including labor at a stanadyne dealer
(they'll last significantly longer if you add power service or some other lubricity enhancer)

Basically if you want to work on your truck, and you're ok with learning everything you need to know from this board, you're likely going to get a truck engine that will last to average 300,000 miles, and will do well with a repower and run another 300,000 without rusting out too bad (as long as you dont have a drop in bedliner. (and you can get a new bed easy enough at a boneyard)

But for any diesel, mechanics are very expensive, you'll want to do your own work. On a 7.3 PSD the work's harder i understand, but on the cummins, 12 valve (pre 1994)(25 mpg 3500s!!!) the work's pretty easy.

I'm pretty happy with my truck, but i get 12 mpg with 4.10 gears, and i'm angry about that. I should get 15-17, and there are folks on this board who do in my truck. Maybe my tires aren't aligned, or my injectors need replaced...

I'd reccomend a 7.3l Powerstroke Ford, they're good all around trucks, but have a lot of the same issues.

If you get a deal 30% less than you see on Edmunds.com, you can afford the ~$1000 of reliability upgrades you'll need to make it last.

[ 08-30-2005, 07:15 AM: Message edited by: Aryeh Levy ]

JTodd
08-30-2005, 04:48
I would echo what others have said about this and other forums accentuating the negatives. My Sub is a 96 2500 4x4 with a lot more miles than the one you are looking at. It is a great truck and I have minimal problems with it (alternator, FSD, wheel hub) in the 3 years that I have had it, and with the help of this forum have been able to take care of the issues and keep it normally maintained.

Not to say that my truck or the one you are looking at won't have problems tomorrow (knock on wood), but I can say the same about any car on the road.

Good luck and keep us posted.

Cowracer
08-30-2005, 04:49
Originally posted by Aryeh Levy:


I'm pretty happy with my truck, but i get 12 mpg with 4.10 gears, and i'm angry about that. I should get 15-17, and there are folks on this board who do in my truck.
I'd bet money that your TC ain't locking up.

I run (ran) mine at a solid 75-80 all the time and I got 14 to 14.5 with the 4.10 gears and stock dually tires.

Also, your speedo may be off, throwing your odo off as well (and your indicated MPG). Run and indicated 60mph and you should take exatly 60 seconds between mile markers.

If you would, post your indicated engine RPM at 50,60 and 70 mph.

you wont get 12mpg on an empty 4.10 truck without SOMETHING being wrong. We'll get to the bottom of it!

Tim

rjschoolcraft
08-30-2005, 05:00
For the record...again...the statement about reduced compression in the 99 trucks is false.

Aryeh Levy
08-30-2005, 05:13
Just looked up Ford's 7.3 Powerstroke vs 6.5 TD both 1996, both 130000 miles, both dark Blue. Ford 4wd 3500 was 6392, the k3500 was 7400.

It depends on the deal. I'd say that if you could pick up a k3500 for under 3k then i'ts fine, the 3000 will pay for half a new engine in price difference. Those prices are private party though.

I bought my 1998 k3500 for 11,000 at auction in pennsylvania, the home of pickup truck country. it had 120,000 mils on it. and then i promptly got it maryland inspected and had to pay 3,000 to get a lot of things replaced. a good mechanical lookover BEFORE you buy a truck of that age is key. i didn't and i got screwed for it.

Aryeh Levy
08-30-2005, 05:17
There's a thread 50 posts long about my problem:

I get 2200 at 65.

I'll take my readings at 65, 70, and 80 for you and respond when i get to work.

the RPM's drop about 200 at 48 or so.

According to the thread i mentioned, everybody says for a 4.10, 12 is acceptable, and don't worry about it. I agree something is wrong.

Aryeh Levy
08-30-2005, 07:03
50 Mph 1850

60 mph 2100

70 mph 2500

80 mph 2900

BuffaloGuy
08-30-2005, 08:57
That's about what I have for RPM vs. MPH but I get 18+ MPG at 65 MPH. Consistent. I can do better if I slow down. Same rear end as you too althought I have a manual trans.

Something is wrong with your rig to get that poor of mileage. The guys here will surely help you!

Aryeh Levy
08-30-2005, 09:12
it's running 23-2400 rpm at 65, i think my TC isnt locking up...

Marty Lau
08-30-2005, 11:40
Aryeh Levy;

It could be your injector are in need or replacement and your timing is off also or both. That will make a difference. And who ever said IP need changing about every 80,000 I think is off. The biggest reason IP get changed is PMD/FSD if you take care of that an IP should last 150,000 miles plus particularly if you us a good fuel additive. I have about 165,000 miles on my current pump and still going strong. But I use aditive with every tank.

RT
08-30-2005, 13:43
Cowracer hit the nail on the head.
RT

patrick m.
08-30-2005, 14:30
i dont think a comparison of fuel milage between a dually, and a 2500 does much good.
just because an empty 2wd 2500 can get 18mpg, i doubt an empty 2wd dually will. (without much effort)

chickenhunterbob
08-30-2005, 14:32
But what I have read thus far is even with great maintenance, one owner vehicles, issues with cracked block, PMDs, cooling, exhaust upgrades, and the list goes on. What is the ADVANTAGE of owning a 6.5. They appear to be plagued with signficant engineering flaws.This, and other similar websites are, among other things, the emergency room for the ailing.

Somewhat akin to walking into the emergency room at a big city hospital and concluding that the human race all has a broken arm, or nose, or has just had a heart attack.

It just ain't so.

I just rolled over 250,000 km, never skipped a beat and yearly average, all driving combined is 21 MPG. Maintenance is what you would expect for this age and mileage, but not much so far has been to difficult for me to diagnose or repair.

markrinker
08-30-2005, 15:58
Just for the record, my truck #2 never did better than 12mpg unloaded. After the '98 motor swap (GM-8 turbo, cooling updates, warranty IP) along with Heath chip, exhaust and Turbo-Master, it still doesn't do any better than 12 unloaded. Lots more power, though! Loaded mileage 9-10. Gearing is 4.10 single rear wheel K3500. Torque converter is new and operational.

(Same guy, same right foot, same loads in my '05 Duramax averaging 14mpg loaded, 18-20 unloaded.)

Aryeh Levy
08-30-2005, 17:43
So, do the torque converter solenoids just wear out on a lot of peoples trucks?

Does injection pump timing really get you 3mpg more?
I've heard that a lot of folks got 12mpg off the lot when they got their 6.5s... i think it's either a transmission issue for the lot of us poor mpg folks, or a balancing issue in assembly?

Diesel Dan
08-30-2005, 18:31
IMO, I'd much rather have my Cummins in my '00 chevy. Only 6.2/6.5 that impressed me with mileage was my '83 sub with 6.2L, 20-21mpg highway. My '00 has a new converter, V/B upgrade, new GM motor, new bosch injectors, new I/P and gets 15-16mpg. Timing is set with TDC offset of -0.7* and is pretty loud when started. 3 of 4 4L80Es have given me problems, have 168K on stock dodge trans(luck on my side there :D ).

In my neck of the woods you generally see 5.7L gassers with more miles than most 6.5s. You have to want one and be willing to take on some extra maintenance in hopes the fuel mileage will pay off. If you get stuck with a low MPG truck....

My case dodge hasn't offered a decent cab size yet. So I bought a motorhome with a Cummins instead :D !

bertram31
08-30-2005, 19:23
I appreciate everyones candid input. I love working on vehicles and typically do not find myself sending repairs to a mechanic. It appears that most work on a 6.5 is reasonable. While I want to remain within a $10K budget I understand that some rework will be required. I will most likely order the SOL-D as good insurance due to fact that I will drive the Burb down from Baltimore to Miami and have it shipped to Guam. I only have a few days to make this happen. If the stock PMD gets me to Miami, great but if not then the backup SOL-D will not leave me stranded traveling down I-95 at 0300 am. Again appreicate your input and look forward to candid dialogue with the Burb brotherhood. r/ Roland (Commander, United States Navy)

DA BIG ONE
08-31-2005, 02:02
Originally posted by bertram31:
I appreciate everyones candid input. I love working on vehicles and typically do not find myself sending repairs to a mechanic. It appears that most work on a 6.5 is reasonable. While I want to remain within a $10K budget I understand that some rework will be required. I will most likely order the SOL-D as good insurance due to fact that I will drive the Burb down from Baltimore to Miami and have it shipped to Guam. I only have a few days to make this happen. If the stock PMD gets me to Miami, great but if not then the backup SOL-D will not leave me stranded traveling down I-95 at 0300 am. Again appreicate your input and look forward to candid dialogue with the Burb brotherhood. r/ Roland (Commander, United States Navy) I think you will not go wrong with this choice. These trucks w/6.5 td's are hot items for export because they hold up well.

I get people almost everyday asking if I'd sell them mine, and I mean some here have very deep pockets and never ask price, been tempted, but still holding out.

Good Luck!

trbankii
08-31-2005, 05:11
Originally posted by Aryeh Levy:
If you buy a 6.5, dont buy quick. Take it to a good mechanic, have them take off the oil pan and examine for cracked block, compression test all 8 cylinders, dont buy one unless you know that the antifreeze has been changed every 50k miles on...

I bought my 1998 k3500 for 11,000 at auction in pennsylvania, the home of pickup truck country. it had 120,000 mils on it. and then i promptly got it maryland inspected and had to pay 3,000 to get a lot of things replaced. a good mechanical lookover BEFORE you buy a truck of that age is key. i didn't and i got screwed for it.
If you don't mind my asking, what all needed to be replaced? Did it show any signs of trouble when you first looked at it? And I thought that Texas was the home of pickup truck country! smile.gif