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GM Diesels Suck - READ ONLY
34 messages, Last post on Sep 09, 1998 at 6:05 PM
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#5 of 34 kcram by kcram HOST
Jun 12, 1998 (4:23 am)
mharde,Maybe bigfur coming to work in a brand new Ford SD will let GM know that they couldn't make a suitable heavy duty truck... nothing lets a manufacturer know their products are weak like their employees buying the competition's products. Kinda like a Gateway employee bringing his Mac to work...
#6 of 34 bigfur by bigfur
Jun 12, 1998 (5:23 am)
Hey guys,I'm just like you. I like style and a whole s#$t laod of power. GM has the absolute weakest deisel on the market. I like working for them but I am not ever going to buy 6.5 deisel unless it was a deal i couldn't pass up(i havent come upon one yet).
Thanks for the encouragement
BigFur
#8 of 34 bigfur by bigfur
Jun 12, 1998 (4:55 pm)
fredwood,I have heard and read(in town hall) many horror stories of GM deisels. There are people on their third or fourth engine by a hundred grand. Currently tey are experimenting with Isuzu and CAT engines, but havent heard anything beyond that.
#9 of 34 kcram by kcram HOST
Jun 12, 1998 (7:14 pm)
FredwoodThe big knock on the GM diesels is lack of power. Until this past year, they hadn't even produced 400 lb-ft of torque WITH a turbo. Everyone is aware of the Dodge/Cummins and Ford/Navistar battle, and the heavy duty truck market shops there because they get power and good economy in a strong truck. The 6.5 needs aftermarket upgrades to match the power, and suffers in economy because you have to keep your foot in it more than the other diesels.
Don't expect the next GM trucks to be successful even with the Isuzu diesels. You will hear "Jap engine" almost immediately (as bad as that is to say), and the fear of expensive replacement parts (from the experiences with Japanese cars) will also drive people away.
#10 of 34 cdean by cdean
Jun 13, 1998 (12:24 am)
kcram,wait to you have to fix any diesel. its going to be expensive as hell whether it was produced in Japan, detroit, hawaii, whatever...
GM diesels were designed at the lower horsepowers for effieciency reasons. i don't know how much yall know about them. the 6.5 turbo was a strong engine up till '94. it gave almost identical performance to ford's turbo 7.3 (pre powerstroke).
My father bought a ton and a half chevy diesel in '94. that year, they change their injection system to completely computerized. there wasn't even a throttle cable, just a wire running from the accelerator to the fuel pump. the diesel was smokeless. you cannot make it smoke, no matter how hard you clutch it or put your foot into it. the engine met emission standards for year 2000 something.
they had lots of software problems. my dads truck would die every now and then when he was slowing down to a stop and clutched it. not fun when your work truck weighs 14,000 empty. a GM engineer would come to the dealership with different stuff, because in '94, the really had no clue what was wrong with these engines. they tried several different computer chips. one of them they tried had awesome power. that motor would smoke like peace pipe, but would it run! they thought pumping up the fuel would keep the engine from dying. it did. but the chip also had a flaw that made injectors miss at idle, and the truck literally shook back and forth it was so bad (at idle).
they finally found the software glitch and the truck has been flawless ever since. but it does not run like a powerstroke, and it gets only moderate mileage, but 12 mpg isn't bad in 14000#. another company with superduty powerstrokes in similar trucks never got better than 7 mpg.
when a diesel smokes, there is more fuel burning than air will allow, or there is too much air. the black smoke you see is unburned fuel. the way GM did this is with an airgate. they carefully monitored the air fuel ratio at every instance, and would actually dump air out of the turbo line, if the mixture was not right. or the computer would cut back fuel, even if you had the accelerator pushed, that way--no smoke. the result: an engine that wouldn't go when you wanted to. basically that diesel grunt that everyone loves, happens you're at low rpms, you step into it, and some black smoke starts coming out the back as you accelerate.
that was longer than i anticipated, but you basically have the story behind the 6.5 GM.
#11 of 34 kcram by kcram HOST
Jun 13, 1998 (3:17 am)
cdean - well-written postI really have to floor my Cummins to get smoke. It *does* have a cat-con, but the new 24 valve doesn't use one, not even in California.
The 6.2 was so weak power and torque wise, and the 6.5 was viewed as a turbo "just to have a turbo". Until the "Powerstroke" version of the Navistar, no one could touch the low-end torque of the Cummins, and that spoiled a lot of people for what a diesel pickup should be. The 6.5 is finally over 200 horsepower; the Cummins and the Nav have been there for years, and the Nav has raised the torque benchmark to 500 lb-ft (which the Cummins will match when Dodge releases its 6 speed next winter).
As you mentioned, the 6.2/6.5 was designed to be as gasoline-like as possible in terms of drivability, but GM has since learned, you need the strength as well.
#12 of 34 bigfur by bigfur
Jun 17, 1998 (10:43 pm)
Has anyone got apprximate numbers on the Isuzu diedel engine.#13 of 34 cdean by cdean
Jun 18, 1998 (12:13 am)
i don't think there have been any kinda of release of any number. the '99 chevy's, all of them, will still get the improved version of the 6.5--440ftlb, 220 hp. i've heard a couple of owners with '97 chevy diesels saying they are much better and more driveable than the previous 3 years version. i wouldn't look for the isuzu before the '00 model.#14 of 34 Duckdog by Duckdog
Jul 06, 1998 (12:02 am)
What everyone need is a Ford with a Powerstroke and a Banks intercooler. You talk about power. And you should see the numbers over 600 foot pounds of torqueAdvertisement
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