View Full Version : GM 6.5 Diesel

12-04-2001, 08:31 AM
Are these good,bad or otherwise? Anyone out there have one or know someone that has had a 6.5? Do you know who mfg. them? Thanks for your advice, pos or neg.


12-04-2001, 12:42 PM
My brother has that on a 99 gmc pickup, its been a good engine but he's never used it hard.That engine was the weak link in gm's
engine lineup.Ford and dodge diesels were just plain better.
As much as i hate to admit it if you are looking to buy a used diesel truck get the ford or dodge.If you are considering a new one i would noy hesitate to tell you to buy gm.
The new duramax gets good mileage and can haul a**

ps I believe gm made the 6.5 themselves
The duramax is an isuzu engine gm controls isuzu owning 50% of it

12-04-2001, 09:34 PM
I have a '97 6.5 and I like it but does not have as much power a my powerstroke.It is very quiet compared to ford.And GM did make these and they are better than the 6.2's.

12-04-2001, 09:37 PM
I own a 85 Dump with a new 6.5 Diesel. The 6.2 blew and I replaced it with the 6.5. This engine is not a turbo (at least not mine) The truck will pull a school down in low gear, but has no balls on the road what so ever. I looked into a banks Turbo kit, but at 2 grand decided against it. If you buy any vehicle with a 6.5 in it make sure its turbo.

12-04-2001, 10:02 PM
I have a 6.5 turbo in my Chevy 3500HD flatbed. I always heard bad things about these engines, but the price was right last spring when I needed a second truck, so I took a chance and bought this one. It had 200,000 miles on it when I got it. It had been a wrecker all it's life, and the owner took really good care of it,(he is a mechanic. It runs great and I have not had any trouble with it yet. The previous owner said the weak part of this engine is the fuel injector pump. He had to put one on about every 50,000 miles. He says the engine should get an oil change every 3000miles. It has made it this far,so I hope if I take care of it like he did, it will last a while longer. My 2001 Dodge/Cummins is a lot stronger, but it only has 25000 miles on it. I think the 6.5 is pretty good, but they need more TLC than the Ford or the Cummins.:)

Fine Lines Lawn
12-04-2001, 10:14 PM
I had one in a 97 C2500. Traded it in because it wasn't 4X4, but I wish I could have kept the engine. Used it for 3 years without one single issue.
Would jump at the chance to get another :)

12-04-2001, 10:34 PM
One plus thing about it is ,its quiet .the cummings sounds like a semi .Im glad you guys have had good luck with it.But one reason until this last year for ford pulling ahead of gm in heavyduty truck sales, was its being less powerful than the powerstroke.
But with the duramax and also stronger gas motors gm for calender year 2001 is going to sell more full size pickups than ford
First time since 1994 chevy -gmc full size pickups have outsold ford and i think the duramax is a very important part of this sucess.

tim cooper
02-15-2002, 03:26 AM
I've gota 96 suburban with 6.5 turbo gota 114000 miles on it pulled trailer with tractor a bit along with 20 foot bass boat.... runs great..had no problems at all out of it. Haven't lost power at all cruises at 75 mph no problem....only problem i have is with axle slap when i have a load behind it.

11-26-2002, 10:58 PM
My friend has a 6.5 Turbo and just replaced the glow plug relay and 3 glowplugs anyone else had this problem or any other problems

11-27-2002, 02:49 AM
Last year I bought a 3500HD with 147,000 miles. That thing was the bigest P.O.S. new fule pump, new injector pump, new turbo new this new that. it always needed something :cry: its gone now thank god.

Shadetree Ltd
11-27-2002, 04:32 AM
Where to begin. I have a 1997 3500 5 spd dumper with the 6.5 Turbo Diesel. In August it broke the crankshaft. The total bill was $18,700 CDN. Chevy mechanic and distict rep felt it broke due to the POOR DESIGN of the engine and 5 spd combo. After a lot of noise Chevy paid approx 1/3 of the bill. The truck is in excellent shape, well maintained and only has 140,000 kms on it. It now has a new factory crate engine, new turbo, new injectors, new brakes, new water pump, new alternator and probably more I can't remember. I find it hard to even call it a diesel compared to the 99 Powerstroke and 99 Cummins we also own. I would never buy another and after being a Chevy fan for over a decade their customer service will make it very difficult to ever own another.


11-27-2002, 10:59 AM
Odin you don't even want me to start on these sick.5 POS. I have friends with them and friends that USED TO HAVE them. Every body hates them.

They wouldn't even fit the bill for a boat anchor. I hate the GM diesels so much that even if some body were to give me a vehicle with one in it, I would put it up for sale right away. Take the $$ from the sale and go buy a Power Stroke or Cummins.