6.5 turbo deisel

jwcinpk · May 29, 2004

Ended up buying a 96 3500 dually flatbed with the 6.5 litre turbo deisel and a 5 speed. Wondering what are some of the good and bad points of this engine? What kind of fuel mileage should I expect? What's this thing rated to tow and how much can it actually tow safely.

snoman · May 30, 2004

It is actually a pretty sturdy little engine and properly maintained it will go for some time. I would feel safer running it flat out all day with a load than a Duramax. GM must have thought so too because it was still offered instead of Duramax in 3500HD's for a year or two after Duramax came out. If it has a 4.10 rear axle ratio a 4 to 5 ton trailer will be quite doable. If you take it easy and run basically flat ground you may squeak another few tons on top of that. I am not a big diesel fan but if I had to have one it would be the 6.5 as a have driven several of them and was quite pleased with the throttle response and usable RPM range of the engine with a stick. They were also a reasonably price option in there day adding only about 2500 to price of truck instead of the 6 to 7000 bucks now.

422 SS · May 30, 2004

It is actually a pretty sturdy little engine and properly maintained it will go for some time. I would feel safer running it flat out all day with a load than a Duramax. GM must have thought so too because it was still offered instead of Duramax in 3500HD's for a year or two after Duramax came out. If it has a 4.10 rear axle ratio a 4 to 5 ton trailer will be quite doable. If you take it easy and run basically flat ground you may squeak another few tons on top of that. I am not a big diesel fan but if I had to have one it would be the 6.5 as a have driven several of them and was quite pleased with the throttle response and usable RPM range of the engine with a stick. They were also a reasonably price option in there day adding only about 2500 to price of truck instead of the 6 to 7000 bucks now.

The 6.5 liter diesel is garbage.I can't believe I just read that someone said the 6.5 was better than a Dmax .If your serious about this truck budget for injector pump failure every 40-50k miles.For several years the vortec 350 had a higher tow rating than the 6.5.If I remember correctly the 6.5 only had a 8,000 lb tow rating in a 4.10 geared dually 3500.They're very weak as far as performance and notoriously unreliable.I'm a big diesel fan but would skip the 6.5 for a vortec 350 or 454.I paid $3990.00 for my Dmax.

snoman · May 30, 2004

The 6.5 liter diesel is garbage.I can't believe I just read that someone said the 6.5 was better than a Dmax .If your serious about this truck budget for injector pump failure every 40-50k miles.For several years the vortec 350 had a higher tow rating than the 6.5.If I remember correctly the 6.5 only had a 8,000 lb tow rating in a 4.10 geared dually 3500.They're very weak as far as performance and notoriously unreliable.I'm a big diesel fan but would skip the 6.5 for a vortec 350 or 454.I paid $3990.00 for my Dmax.

This poster is full of it. It was a fine engine and still is. I know of a few with well over 100,000 miles. I could give the number of a guy the blew up two Duramax engines in same truck towing a 8000lbs skid loader daily in a years times. He had a 6.5 for a few years before that one and it never came apart doing the same thing as was runnin fine when he traded it in on the Duramax time bomb. (it was when they first came out too) Sure the Duramax looks good on paper and it can do well but when you run 20 to 25lbs of boost constantly to maintain output it creates a lot of stress and when things go bad, they go bad quickly. The 6.5 is a far better towwer than a 350 and has nearly 100 lbs more torque at 2500 RPM than a 350. With 4.10 gears and a 5 speed it will pull some serious weight. Maybe not as fast up a hill as a new Cummins or Power Joke but it will make it just the same reliably and maybe even moreso. Even the old 6.2's were reliable but weak. My horse vet put 150,000 on his first 6.2 in the 80's before he had to have pump rebuilt and then drove it past 200,000 before trading it in. The only "bad" diesel GM ever built was the old 350 diesel based on a olds 350 block. That thing was a time bomb. I knew a few that had them in cars and they either swore by them or at them. My neighbor had a olds 88 with one back in 80's and loved mileage he got on frequent trips to michigan (28 to 30 mpg). He got 120,000 mile out of it then motor suddenly blew without warning.

I say again, there is NOTHING wrong with a 6.5. If I were to have a diesel, that would be the one I would get as I have driven several and a few in the rockies. Matter of fact when I was looking at new trucks in Helena Mont in 1995 they had this long climb up a pass going north out of town that dealers let you test trucks on (about a 10 minute climb) I drove a Cummins a Ford and a GMC up it with diesels and sticks. THe 6.5 (190hp) was the fastest and would hit and hold 80mph up it, the Cummins (175hp) while a bit quieter under load would only do about 72 or so. The Ford could not even get past low 60's. That 6.5 was alway willing to "run" and was fun to drive as it would wind past 3000 rpm without a fuss. Somewhere around 99 or so GM changed 6.5 pump to drive by wire so you have old mechnical pump in 96 that should give good service. I am not a fan of "drive by wire" throttle control on any engine and do not currently own any vehicals using it. I am old fashioned as I like my foot hooked directly to the throttle plate or injector pump, not to a sensor.

jwcinpk · May 30, 2004

Well it's good to know someone doesn't think I wasted a little under $10000. I ran up on this thing and it was exactly what i needed in the way of a truck. I looked at the others and wanted a duramax, but I figured I could get 3 of these trucks to one duramax so what they hay you know. Truck has just a little under 100k and it seems to run good. It's my first deisel and I haven't towed anything heavy with it yet, but I know it pulls a whole whole lot better than the 350s I've had!

snoman · May 30, 2004

Well it's good to know someone doesn't think I wasted a little under $10000. I ran up on this thing and it was exactly what i needed in the way of a truck. I looked at the others and wanted a duramax, but I figured I could get 3 of these trucks to one duramax so what they hay you know. Truck has just a little under 100k and it seems to run good. It's my first deisel and I haven't towed anything heavy with it yet, but I know it pulls a whole whole lot better than the 350s I've had!

Take time out to change all fliuds (tranny, xfer case and axles) to get it up to date. Change oil every 3,000 miles or less with 15w40 CF oil and keep up with fuel filters and it should service you well. I fully agree with you that at 10 grand it was a very smart buy and 3 or 4 at that price is a much better value than a new Duramax for same money spent and just one truck! Besides, a new Duramax will not pull 3 or 4 times better nor last 3 or 4 times longer either. Great buy and good luck!

robsawatsky · May 31, 2004

The 6.5 did have some fairly well documented problems, mostly with fuel system issues. But my father-in-law has had a 94 since new and likes the towing capability and fuel economy. But, yes he has had a few recurring problems specific to the diesel engine.

snoman · May 31, 2004

I believe 94 was first year for the engine and there will be teething problems. Plus, fuel system isuues or glitches are preferable to internal engine issues. I never get a new engine or tranny the first year it is out myself. I let someone else work out the issues. Ford had some serious one with it new 6.0 Power Joke diesel that effected many trucks (excessive fuel from injector leakage that could dilute the crank case oil and toast main bearings) so they all have teething problems. I have heard of people have a lot of problems with Dodges recent (since 2000) electronic injection pump on Cummins too. The 6.5 was a improved 6.2 and should be rock solid internally with any issues being in new style fuel system or injectors and those should have been worked out after a few model years anyway. I am not a diesel nut but if they had had one when I bought my 2000 k3500 new I "might" have gotten a 6.5 but there were none to be found at the time in a standard cab truck.

RonJ · June 1, 2004

GM will replace the injector pump up to 11 years or 120,000 miles. mine has been replaced twice in 68,000 miles ( 1996 model)

snoman · June 1, 2004

My understanding is that a lot of this is due to fuel quality. I would invest in a first rate after market filter and water seperator to use in tandum with stock one

16gaSxS · June 1, 2004

I have over 165,000 miles on my 6.5TD and have had only a few problems with it.

I am on my Second injection pump, the first was replaced by GM with about 25,000 on the truck and was an earlier generation pump. If I had to replace my truck today I WOULD by another 6.5, I realy like the fact I can work on it myself and parts are not out of reason. Injectors for example are about $40 each for the 6.5 and $200each for a Powerstroke and $700+ each for a DuraBux. If you want to know more about 6.5's PM me.

I EXPECT to run my 6.5TD too 300,000 miles. If the yahoo who called the 6.5 Junk worked his truck as hard as I have worked my 6.5TD it would be trash by now. I tow a load about 50% of the time.

snoman · June 1, 2004

I have over 165,000 miles on my 6.5TD and have had only a few problems with it.
I am on my Second injection pump, the first was replaced by GM with about 25,000 on the truck and was an earlier generation pump. If I had to replace my truck today I WOULD by another 6.5, I realy like the fact I can work on it myself and parts are not out of reason. Injectors for example are about $40 each for the 6.5 and $200each for a Powerstroke and $700+ each for a DuraBux. If you want to know more about 6.5's PM me.

I EXPECT to run my 6.5TD too 300,000 miles. If the yahoo who called the 6.5 Junk worked his truck as hard as I have worked my 6.5TD it would be trash by now. I tow a load about 50% of the time.

Well put! The 6.5 is a fine proven engine and GM should have keep it as a baseline diesel option after Duracraps came out.

422 SS · June 2, 2004

It good to see a few people have had good luck with the 6.5 liter.A friend of mine who owns a large construction company with probably 75 trucks was a 6.2-6.5 man for a long time.He bought a conversion 96 crewcab 3500 dually 6.5 back in 96.This was the first $50,000 pickup I had ever seen.He picked the truck up from the dealer drove it home and it never started again.The dealer sent out a semi size flatbed to take back to the service dept where the mechanics were unsuccessful on getting it to start.It was trucked to Detroit for the engineers to figure it out.My friend was swapped into a 454 truck that while a fuel sucker it would actually start and run..That experience and the weak suspension and brakes on the old C/K series combined with lack of a good diesel made him switch to Ford 350 and 450's with PSD's.If GM didn't have the Dmax I would be driving a Ford.Let me ask you 6.5 lovers why do these trucks have such a terrible reputation.If I'm wrong I don't mind being corrected.I work in the construction industry and it seems like everyone has a 3/4 or 1 ton truck.None of them are 6.5's and if you bring it up people laugh about the 6.5 and call it a POS.I have only driven one vehicle with a 6.5 and it was a dog even empty.I don't consider swapping injector pumps every 50,000 miles reliable.

snoman · June 2, 2004

It good to see a few people have had good luck with the 6.5 liter.A friend of mine who owns a large construction company with probably 75 trucks was a 6.2-6.5 man for a long time.He bought a conversion 96 crewcab 3500 dually 6.5 back in 96.This was the first $50,000 pickup I had ever seen.He picked the truck up from the dealer drove it home and it never started again.The dealer sent out a semi size flatbed to take back to the service dept where the mechanics were unsuccessful on getting it to start.It was trucked to Detroit for the engineers to figure it out.My friend was swapped into a 454 truck that while a fuel sucker it would actually start and run..That experience and the weak suspension and brakes on the old C/K series combined with lack of a good diesel made him switch to Ford 350 and 450's with PSD's.If GM didn't have the Dmax I would be driving a Ford.Let me ask you 6.5 lovers why do these trucks have such a terrible reputation.If I'm wrong I don't mind being corrected.I work in the construction industry and it seems like everyone has a 3/4 or 1 ton truck.None of them are 6.5's and if you bring it up people laugh about the 6.5 and call it a POS.I have only driven one vehicle with a 6.5 and it was a dog even empty.I don't consider swapping injector pumps every 50,000 miles reliable.

You would have to look at over all gearing to find performance problem. I would rather replace $40 injectors than $400 ones anyday. I know a guy the blew two Duramax engines in a years time and is work on his third towing a 8000lb skid loader daily and it was factory equiped to do it too! HE had replace a 6.5 with it that had run for several years with minor maintaince and was runnin fine when he traded it in for the promises of better performance and longer life.

16gaSxS · June 2, 2004

I know of a number of 6.5TD that have over 300,000 miles with not much more than normal maintance. The problem that you really don't understand is not in the Injection pump itself as much as the PMD= Pump mounted driver which controls the IP. It is a electronic component mounted on the IP and it gurns out from heat from the engine. The IP manufacture and GM screwed up big time mounting it on the pump in the engine V. Most of the replaced IP have been replaced because of a $275 PMD and many of the Diesel tech are parts changers and don't UNDERSTAND how this engine works and would rather just change the Injection pump out rather than LEARN the engine and LEARN how to fix something.

Changing a pump is about $1500-$2000 propsition. Too many people know NEXT to NOTHING about these engines and spout off about how they are garbage because they hear something or know someone who has had problems because they haven't found some one who really knows what is going on to have fix the real problems. I don't consider having driven one once to be qualified to make any reasonable coment. As far as not having any power I would hook up my truck to any trailer that any other standard 3/4 ton pickup with a V-8 gas engine with simular rear end ratio and see who can pull for 300+ miles in the mountains of Montana, or the interwest, (Rocky Mountains) only two things count time and fuel used. I'll pass you on the grades and at the pumps.

Better yet I'll go against any factory 350 CID gaser with atleat 150,000 miles with out being rebuilt!. I'll hook it up to the 1000 gallon water trailer I haul with my weak 6.5TD and see how well it does? Oh yeah I have a 3.42 axel ratio there are plenty people pulling 12,000lb. fifth wheels with 6.5TD.