GM 6.5L Diesel-Opinions?

tmats1tmats1 Member Posts: 35
edited March 2014 in GMC
I've got a friend who doesn't have a 'puter. I
volunteered to research a truck he's considering.
He's a rancher who is looking at a '94 GMC CC
dually with the 6.5L diesel engine. We're both
aware that it's not a great engine, or
Chevrolet/GMC would've sold more of them; but is it
so bad that one should not even be considered? The
truck is apparently loaded, clean, low mileage,
and priced reasonably. I'd appreciate hearing from
owners and former owners. Thanks


  • rrichfrrichf Member Posts: 211
    The first question that comes to my mind is 'How do you KNOW that the odometer hasn't been clocked?'
  • sclivingstonsclivingston Member Posts: 9
    My nephew is a service manager for a GM dealer who sells and services GMC trucks. My nephew told me, when I was making my decision to buy a Ford or Chevy with a diesel engine to go to the Ford - in fact he had just purchased a 99 F250 CC Lariat with the Power Stroke diesel. He said that there were a lot of problems with the GM diesel, and some of the problems had no solutions and sometimes they couldn't firgure out what the problem was (and he is a certified diesel mechanic himself). He also said he sees a lot of them in for work in a more disproportionate number than gassers.
  • azchevazchev Member Posts: 2
    Who made '94 the GM 6.1L diesel?? and what is their reliability??
  • superjim2000superjim2000 Member Posts: 314
    You mean 6.2? GM made it. I worked on a few when I was in the military, I wouldnt recomend them to anyone. I'm a Chevy guy but this is a very poorly designed engine.
  • azchevazchev Member Posts: 2
    Any experience w/ the new '94 6.5 diesel?? or the chev tranmission on the 94 trucks??
  • lwmaylwmay Member Posts: 3
    had a 93gmc 3/4 ton ext cab until last year. pulled a 10,000lb. fithwheel , diesel did ok job granted it's not a dodge but i was satisfied overall. after 150,000 miles truck was in shop only 2 times for minor problems, have heard many stories from other owners but truck did a good job for me
  • tubeking1tubeking1 Member Posts: 6
    Had 2 6.2's and 2 6.5 TD's all ran very well and had only minior problems. I truley belive the 6.2 6.5 rap is for a large part due to untrained techs and uneducated owners. If you do buy a 94 or 95 6.5 make sure it has the "green tag" pump. this is the one thats revamped for low sulfur fuel. Myself and friends have probably owned 20 different dsls, and NONE of them are perfect. I worked the crap outa of my last 6.5 towing 9 to 11K 300mi several times a month. Go to the 6.5 turbo diesel website for great info on this engine and mods and fixes. diesel page ?
  • rrichfrrichf Member Posts: 211

    "I truley belive the 6.2 6.5 rap is for a large part due to untrained techs and uneducated owners. "

    Truer words were never spoken! Unfortunately it is true of all consumer diesels. With mine I've had people tell me to put a quart of ATF in the fuel tank with every 20 gallons. Other have said peanut oil is wonderful and once a service station attendant told me that a gallon of gasoline every 3-4 tanks would clean out the injectors and not harm the engine. Usually I just smile, thank them for their advice and move on. My '92 non turbo 7.3L went through the change to low sulphur fuel without a hitch. I always add a diesel fuel conditioner to each tank. (One ounce per 10 gallons of fuel.)

  • rkvlellrkvlell Member Posts: 1
    For tmats1,RUN, do not walk, as fast and as far as you can to get away from any Chevy diesel, especially the 1994 6.5L Turbo!!!

    For tubeking1, you are the only human that I have encountered live or via internet that says that have had no problems or only minor problems with there Chevy 6.5L Diesel!

    I purchased a new 94 model, changed the oil and filter, etc. regularly. It is now parked at my barn with a blown engine w/only 144k miles, due to chevy's inferior design/quality and their incompetent Mr Bungwrench technicians. It has been in two different chevy dealerships for service of the exact same component - Diesel injector pumps; not once, not twice, not even three time, but six repair/replacement and is down for the seventh time. The only thing that Mr. Bungwrench got right was when he said if we don't get this taken care of it will damage your engine, IT DID, and chevy DOES NOT want to hear about MY problem. Oh, the first six attempts to fix the problem were within the 100000k warranty, with a promise that each time it would be OK. No real surprise when chevy customer service informed me that I was out of warranty and it was MY PROBLEM NOW. If you buy a chevy diesel, make sure you have a good lawyer on retainer, you will need him/her real soon.
  • leathal02leathal02 Member Posts: 114
    two 6.5 TD's

    a '94 and a '98
    the '98 has been flawless so far even though it only has 25000 miles on it...but i has pulled some extremely heavy loads..probably more than it is rated for

    the '94's only complaints is the injector pumps...put 3 on..and havent put another in for probably 30 or 40000 has damn near 100000..and it carries a very heavy utility bed loaded 24/7 so it is worked pretty hard

    no complaints from me or the people around me who drive them....

  • cdeancdean Member Posts: 1,110
    '94s were nothing but fuel pump problems. they finally got them fixed around 95. so if you are looking at a '94, better check and see if it has the latest fuel pump.
  • cdeancdean Member Posts: 1,110
    oh, and I can also attest to untrained technicians. In '94, when the computerized pumps came out, my dad had the typical problems with them. NOT ONE person in the area even knew that they were coming out with electronic pumps, much less knew what to do with them.

    The only help we got at the time is from GM field engineer was making rounds thru the area consulting on the diesel probs.

    but all the in house mechanics--they could fix and clean injection systems and waterpumps, but knew absolutely nothing about the diesels.
  • cdeancdean Member Posts: 1,110
    i meant gas injection systems
  • akanglakangl Member Posts: 3,281
    We have a 1996 GMC x-cab 4X4 with a 6.5L diesel. We bought the truck used in November of last year, it had 48,000 miles on it. We now have 58,000 miles on the truck and other than a very frustrating stalling problem that took the dealer 4 months to figure out the truck has been wonderful. They finally figured it out when the truck was towed in to the dealer and I refused to take it back until they fixed it, it spent 15 days there but came out fixed and hasn't been a problem since, turned out to be the PCM. We live in Alaska and its my pick for a vehicle to drive when the temp hits -40 or colder, it puts out great heat and always starts as long as the engine heaters are plugged in. Of course it will start down to -20 if they aren't but it isn't happy about it. We were very hesitant to buy a GM diesel, but we are very glad we did, its a great truck......I just hope it behaves for a few more years.
  • hdriderhdrider Member Posts: 49
    I've owned a Chev K2500 6.5L TD 4x4 since 93 (bought new). Had the fuel injector pump rebuilt or replaced six times in the first 60K miles by the dealer. Finally got it right... Also had a no-start problem after that, that ended up being the dealer-installed engine kill switch failing. Once removed, no more no-start problems, but it still ran like crud. Finally last year I found a diesel mechanic in Durango, CO named... Bob... who set the timing CORRECTLY (as the dealer apparently couldn't) and she runs like a dream now! I now have 125K on it, and she's running quite well. If it wasn't for the fact she's paid for, I might start looking at the new GM/Duramax truck... If you're ever in Durango, CO, look up a diesel mechanic named Bob. He's the best I've found in 7 years.
  • gillman1gillman1 Member Posts: 1
    I have had a 1993 Chevy Dually Extra Cab with the 6.5L Diesel since it was new. I just rolled over 101K miles and have had no problems since day 1. Everything I ever heard was GM changed it in '94 and that they had alot of problems. I certainly can't complain (other than it doesn't seem to get as much mileage as the Ford and Dodge Diesels). I pull a variety of gooseneck trailers: 3 horse trailer and 24' gooseneck full of Hay with no problems. I am a little concerned about the day I ever get ready to sell it due to the bad rap that engine has taken over the last several years.

    Overall, a heck of a truck.
  • meredithmeredith Member Posts: 575
    After 30 or more days of inactivity....

    this topic is being "frozen." It will be archived or deleted in the next 10 days or so.

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