View Full Version : Chevy 6.5 Diesel Yes Or No?

03-11-2007, 11:40 PM
I know there are other threads about this but not specific enough. I'm looking at a 1995 3/4 ton diesel 4x4 suburban with 185k on it, the injector pump just started to quit, do they "start to quit" or just quit, I know nothing about a diesel except they smell cool:laugh:. The truck is in descent shape for it's age, the U-joints were just replaced and one power window dosen't work. It started right up with no smoke. Iv'e heard the 6.5 is not a very good motor, is this true or no? I only want it to pull 2 ztrs and my boat so even a gutless motor can do that:weightlifter: . The seller is asking 3k for it, dose that sound fair? (KBB in good condition is over $6,300) I can get it repaired for 1,000. What do you think the life expectancy is on the motor if well maintained?
Sorry for a long post but this is a large investment for a 16 year old kid!

03-11-2007, 11:47 PM

03-12-2007, 12:29 AM
i would pass...the old gm diesel is not very good. they dont tow very well at all, they just get pretty good fuel mileage. and they break down alot.

Gravel Rat
03-12-2007, 12:44 AM
I wouldn't buy one they are not a very good engine. With that kind of mileage on the motor now its running on borrowed time.

03-12-2007, 10:00 PM
That's the exact motor that changed me over to Ford! Biggest piece of **** I ever owned- more shop time than road time.

Injector pumps- keep stock on them cause you WILL need them. Keep the 3K and run from that one!

03-12-2007, 10:03 PM
I have that same truck it has been in my family since day one and has 225K on it and is running just like the day it was drove off the lot.

03-13-2007, 12:08 AM
Id pass, My family had a 96 3500 6.5, it did not have enough power to get out of its own way! Never mind loaded, Id get a ford powerstroke w/ 250k miles before this! Aim for a 95.5 & up fords, or dodge cummins, There both super relieable! The new duramax is a great motor, in fact My family bought an 05 after we swore we would never get another again! But your proll not looking to go that high. Just my 2 cents

Jason Rose
03-13-2007, 12:24 AM
I looked at a '93 with a 6.5 in it. The overwhelming consensus was to run away! It's a gas 350 engine that's bored out and converted to diesel. There's no where near enough oil in the engine, Starters burn up annualy, amoung a laundry list of other problems that plauge them. One out of ?? were good engines and would go for a long time, but most blew up at 60,000 miles or so.

03-13-2007, 10:03 AM
Steer clear of the 6.5. The chevrolet gassers are okay.

03-13-2007, 07:22 PM
I own a 95 3500 4X4 dually with the 6.5. Good truck and good motor. It aint a duramax or powerstroke or even a cummings. it is what it is. A small dependable low hp diesel engine. You mentioned your injector pump starting to quit, does the truck flash the service engine light, get the codes read before just bolting on expensive parts. It might not be the injector pump. It might be as simple as a $12 oil sending unit. The oils sending unit supplies power for the lift pump that provides fuel to the injector pump. The lift pump itself might be bad, $50-$80 bucks for a new one. The motor will still run with a bad lift pump or bad oil sending unit, just not as well, but running the truck with the lift pump not working will wear out the injector pump and thats big $$$. I feel most 6.5 injector pump failures can probably be traced back to the lift pump not supplying the fuel to the injector pump.

The pulling power of the 6.5 can also be attributed to axle gearing. Some of the suburban and pickup trucks had gas mileage gear ratios. If you are going to tow with the truck, look for one with at least 4:10 gears, 4:56 are even better. Your fuel milaeage will suffer from the lower gears, but you will be much happier when you hook to a trailer and hit a big hill.

03-13-2007, 09:21 PM
If you get the 6.5 invest in a PMD cooler. It will help with the inj pump failures.

03-13-2007, 10:53 PM
I am going to let this truck go. Thank you for all the help:cool2: .

03-14-2007, 01:43 PM
Have a 94 GMC 3500 (108K) with the 6.5 and like it a great deal. From my reading and mechanics advice it comes down to service. Most people don't perform the service this engine requires and they have problems with it. For example the injector pumps (or the controller chip) typically fail about 130K if your not diligent about changing the fuel filter at least every six months (every three months if using bio diesel). Oil changes every 3K, glow plugs on a regular basis (poorly functioning glow plugs are often the reason for starter failure). Also, a set of Optima marine batteries and new heavy duty cables work wonders for starting. An engine block heater is a must also.

A mechanic friend had a tow truck with the 6.5 in it, went 750K miles. They had a propane injection system and changed the fuel filter every 3 months. They had a total of 3 injector pumps (over 250K for each pump) 4 clutches, a few sets of glow plugs and almost nothing else but regular oil changes.

If your on a very limited budget stear clear, the service for this engine must be done or it will have problems, if you can afford the service and an injector pump every 250k the engine should be just fine. The turbo versions have enough power. Also, you should learn to drive them differently, there is no reason for this engine to ever go more than 3000 RPM and you should deadshift it (let off on the accelerator, shift, then apply power again). Power specs for the turbo versions (2000) got to 220 HP and 440 TQ, there is a performance chip for these engines by BP. I second the advice given earlier about a cooler for the PMD.

Check out the last few issues of Diesel Power (Feb 07, I think) they are featuring this very engine as a good swap canidate and they address some of the concerns brought up in this thread. One thing they did mention is that it is often the chip on the injector pump that fails and many mistake this for a pump failure instead.

From the thread I think you're right to pass on it at this point as care on this engine is expensive and it sounds as if your just starting out.

However, think about the total costs, at $6K truck cost (for me), plus about $2.5K in new tires, batteries, and clutch and an expected $1.5K injector pump and $1000 in oil and filters I should be able to get 5 years use and expect it to still be worth $4K ($11K costs less residual value of $4K = $9K). For a 2001 Dually Duramax the best price I can expect is about $15K, over five years I'd expect $2.5K in maint. and I'd loose about $8K in value ($25.5K costs less residual value of $7K = $18.5K costs).

Spend $18.5K or $9K over 5 years for my truck, Hmmmm pretty easy decision for me, I'll take the 6.5 becuase they work well with proper service and my total cost of ownership will be less precisely because so many people don't understand the engine and as a result I can get a good truck for a fraction of the cost of a newer diesel.

My second choice - a 1999 Dodge 3500 standard trans. with the cummings engine - about $13-$15K to purchase but the cummings will easily go 400K with good service. Avoid the auto trans. (or plan on replacing them), none of them are heavy duty enough to stand up to lawncare/snow removal over time, though I do prefer them for ease of driving.

J&R Landscaping
03-14-2007, 02:15 PM
The older 6.5 engines were not very good at all. I don't know about the injection pump failures but I do know they can blow seals or leak. I would only look at a 6.5 if it was in a 98 or later model year truck. Thats what a local tow truck driver told me. He had a 94 GMC wrecker with the 6.5 and it needed a rebuild before it hit 85,000 miles. His 98 Chevy rollback with the 6.5 under the hood has over 180,000 miles on the original build.

03-14-2007, 08:02 PM
J&R. I am pretty sure the engine change with the 6.5 took place in the 95 model year and would be the same engine that is found in the 98 model. 98 model probably has a few more electronics. I think 95 is OBDI and the 98 would be OBDII. I can read the codes on my 95 with just a paperclip.

03-18-2007, 04:37 PM
My 1995 chevy 3500 srw has the 6.5 in it and has had its problems but overall not a bad engine. The biggest problem I had was the pmd overheating and killing the engine while driving. So I moved it as far from the engine as possible, and that has done the trick for that. The engine only has about 45,000 miles on it because the previous owner had a new engine put in under warranty in 2000. I also have an 06 duramax which pulls really nice but I can still pull pretty good with the 6.5. Most chevy diesels have problems when they first come out and this one has had it share of problems.

03-18-2007, 05:14 PM
O-kay first thing you should ask yourself - can you afford the price of diesel no matter where you go diesel's price is sky high. gas may come down but diesel never does take it from a pass over the road driver. the next thing you should ask your self why chevy? chevy or GMC does'nt make a good pulling truck Belive me I use to be a bowtie fan but you can pry me outa my RAM. If you want a good truck look at a ( I cant believe im saying this ) but a ford or a dodge will do what you ask from it now and 20 years from now. you can usually find a good decent one in your local classified sect. sounds like the truck your looking at has trouble and will always have trouble
just my oppion I wont charge you for it this time.

03-18-2007, 08:18 PM
This is why it is called the "error net". The 6.5 is not a converted gas motor and neither was the 6.2L. The 5.7 diesel made in the late seventies was a converted motor and a POS it was. The 6.5 was introduced in 1992. The first two years of that motor had a mech. fuel injection pump. They ran good and compared to trucks made at the same time were close in hp and torque. No OEMs diesel made in this time frame will compare to those available now. The 94-95 model years were problematic (fuel injection problems mainly)most with high mileage will have had the mods done but 94 was the first year of the "fly by wire" injection pumps not a great move by GM. The 1997 model saw some significant upgrades (mainly injector and cooling mods) and the motor was improved upon (lubrication improvements on the pistons and bearings). I would agree that the later model years are better. The 92 and 93 models were also more reliable. I have owned two trucks with these motors a 93 CC 3500 and a 1998 3/4 ton extra cab. The 93 had 250K on it when I sold it. I replaced the turbo and 5 speed tranny that was it, I pulled the guts out of that truck. The 98 never saw the inside of a shop except for warranty work on the CD player. The burban may or may not be a great deal, like anything else you have look at what you have. As far as the 6.5 being a great motor; no probably not. I never had issues with them or the 6.2 that I put 225K on. My only complaint was the lack of power. My equipment got heavier and the trucks could not keep up. This motor as far as reliability would compare well to the Ford 6.0, some run and some didn't.

03-19-2007, 12:44 AM
i have a 96 chevy diesel and it is not a bad truck. i have a problem with my injecter pump right now. i truck till runs but u can tell it is not pumping enough fuel to the injecters. a injecter pump it $1200. if u can find it for $1000 please let me know

03-20-2007, 01:14 AM
Man, before you spend $1200 on an injector pump, pull the codes or have someone do it for you. There is an awfully good chance there isnt anything wrong with your injector pump. Odds are its the lift pump that supplies fuel to the injector pump, control modual, or the oil sensor unit. The oil sending unit supplies electical power to the lift pump. Might even just be the fuel filter. Pull the codes and save some dough.