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6.5 diesel problems

0patience0patience Oregon CoastPosts: 1,586
edited April 2014 in Chevrolet
Let me guess, it is in a 92-96 truck and it is giving you problems with a power loss??


  • tebduntebdun Posts: 3
    I have a 93 Chevy 3/4 ton truck with a 6.5L diesel and 89,000 miles on it. It lost its head gasket and they say that the motor is junk. I flush the radiator once a year and change the oil regularly. What else could I have done to prevent this? GM says that because of the year and the miles there is nothing they will do about it. This is the third of four new GM vehicles that I have purchased. Is this what we can expect from GM? Less than 100,000 miles and then throw them away? I do not expect GM to give me a new motor, what should I expect? I am currently looking for a new truck. Can anyone give me a reason to buy another GM? Is it just the diesel? The truck performed flawlessly up to this point.
  • tebduntebdun Posts: 3
    You hit the nail on the head, it didn't have the power it had when I bought it!
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 57,360
    The truck's way out of warranty, so I don't think GM legally owes you anything. Machines are unpredictable. Some trucks like yours will go 150K, some only 75K. It's hard to know what will happen the next time around. I don't think this engine was particularly wonderful to begin with, so maybe next time you can spend more time at Edmunds here and study the repair history, recalls, etc. and come up with a good purchase for your next truck.

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  • tebduntebdun Posts: 3
    I guess where I am going with this, is this a major flaw on the part of GM? I have put in brakes, clutch, injectors, things of this nature that I though were normal wear. So when we found compression in the radiator, we took it to our GM dealer, told them to get it back soon as possible, and assumed the cost would be all ours rightfully so. I was not prepared for $7200 for a new motor. If there was a problem with the 6.5 when we bought it new in 93 I wasn't aware of it. If anything I was told the diesel was beter than the 454. If there was a recall, or any preventive matinence, or if I should have put in a new gasket to be safe I would have done it!

    Perhaps I am way off base here.
  • 0patience0patience Oregon CoastPosts: 1,586
    90,000 miles is about the right life expectancy of the 6.5L
    We have about 6 of them and everyone of them has lost the engine between 85,000-120,000 miles.

    Pretty much, it is the nature of the beast.
    From 92-96, the 6.5 was (I'd say it was a disaster, but someone would take it wrong)not a great engine.

    The new Chevy trucks won't be carrying that engine, thankfully.
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 57,360
    It's hard to say whether an engine that goes 89K before dying is "defective". There is no one standard for typical engine mileage. If it's an old VW engine, 60,000 is plenty. If it's a Toyota, 150K is pretty normal.

    Diesels generally lead a hard life. I don't think the 6.5 was built heavy enough for the job, but man, proving that 89K engine failure is "premature" is a tough row to hoe.

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  • discusteddiscusted Posts: 1
    The company i work for has 5 GMC 3500 HD trucks with the 6.5 diesel engine. The oldest is a 98 with 117,000 miles. This truck is a 5 speed manual transmission and has to have a new clutch every 30,000 miles. It has also had a cracked valve and fuel injector pump. We have one truck that just had it's third engine installed. We have had numerous problems with all the trucks. This makes it very difficult to run a service business. Please continue to post any problems found with this engine.
  • 0patience0patience Oregon CoastPosts: 1,586
    Several turbo failures, many injection pump failures, although GM ate most the cost on the ones that had less than 100,000 miles on them.
    4 engines had headgasket failure.
    3 engines had valves the self destructed.
    Most engine failures were between 90,000-110,000 miles.
    3 trasmission failures at less than 90,000 miles.

    Those are just the major repairs.
  • hdriderhdrider Posts: 49
    I've had my 6.5L since new. I have 136K+ on it. The manual fuel injector was replaced or rebuilt six times in the first 60K under warrenty. That lasted until 134K+. Over Christmas, it started leaking so I had to have it replaced again. This time they put on the new electronic fuel injector for $1200. Wasn't expecting that... ouch... Now I have a surging problem at 1500 RPM. Not undriveable, but certainly annoying. I've also replaced one cylinder injector out of pocket, as well as a starter. Needless to say, sounds like I've had more good luck from my truck than most!

    My truck has always been a work truck, but not necessarily a heavy hauler. I've done numerous cross-country moves hauling loaded trailers with a full bed, but not much else. Haven't really STRESSED the engine, but she's always pulled the loads I've asked of 'er just fine. EVen over 10,000 foot mountain passes.

    My current problem:

    Every now and then, after I park, it won't start. All console gauge indications look like I just didn't have the clutch all the way in (i.e. battery needle swings, message lights blink, etc.) I've tried re-pressing the clutch to the floor, turning the ignition off then on, and just letting it sit. Nothing. The starter was replaced and that didn't help. A dealer installed ignition kill switch was removed and that didn't help. Batteries and cables replaced, nada. The only thing that works is getting the truck rolling and putting it in gear. Not popping the clutch to start, just putting it in gear. That seems to jar whatever the problem is loose and then it starts. I'm thinking it might be a flat spot on the gear in the transmission, but not sure. Any ideas?

  • akanglakangl Posts: 3,650
    You guys are scaring me!! My husband and I own a 1996 GMC K2500 4X4 6.5L TD with 73,500 miles on it. We bought it used in Nov of 1999 with 48,000 on it.
    I can't say that its been a perfect truck, its had its moments, like the time 2 months after we bought it, I was sitting at the bus stop with my 2 kids waiting for the bus, it was -40 outside, and the truck just quit, took 5 minutes to get it started again. That problem went on for 4 months, the dealer didn't have a clue, it would happen at random, driving down the highway, idling in the driveway, basically anytime. They replaced the fuel filter, lift pump, and driver on the injection pump before figuring out it was the PCM. Of course they managed to screw up the timing on the truck when they replaced the PCM, we just got that fixed by our trusted mechanic a few days ago. We didn't find out about it until our mechanic happened to put his computer on the truck to check something else. After the timing was put back in factory specs the power increased quite a bit and the fuel economy went from 16.9 mpg on the hwy to 20.5 mpg. Other than that we have replaced the alternator. We also had some engine leaks fixed right before the diesel warranty was up on May 22.
    Guess we can't really complain, its a nice truck. I hope we can get another 100K out of it before any major repairs. It does still have its original injection pump which I have been told is unusual, it also is a great winter truck, even at -50 will be putting out heat at idle after a 15 minute warm up and will start at -20 with no engine heaters plugged in. Our mechanic says its one of the best running 6.5s he's seen and he used to be the diesel tech at a chevy dealer.
  • 65td165td1 Posts: 1
    anyone having problems with a 6.2/6.5 diesel should check out the 6.2/6.5 diesel page. It tells everything you would ever like to know about those engines . I have a 6.5 and have had good service with it. These engines have had their share of problems mostly in the 93 to 96 years. The diesel page is not a GM site itis just diesel owners who have alot of experience with those engines.
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