Off topic - 6.5 GM Diesel any good?

[NUKEMAN]

Can get a '99 Suburban 1500 with the 6. 5l with 88k VERY cheap. I have zero experience with them. Are they any good (better than the 6. 2l)?

 

[MMeier]

Not much better. . a turbo diesel in a half ton, what were they thinking !!

 

[TPCDrafting]

Dad has a '94 Chevy 1500 pickup with the 6. 5 auto. It's no cummins by far, but he has 190k on it and it will still out pull the same truck with a 350 in it. Better mileage as well. Just keep it plugged in when it's cold. Plan to get the relocation kit for the electronics module that is mounted directly above and between the heads. It does not like to get hot.

 

[jjdiesel]

The 6. 5 actually has a very good reputation... . I wouldn't hesitate, FWIW.

 

[AKaiser]

We use 6. 5 GM Diesels in the HMMWV. The Up-Armored M1114 (eleven fourteen) uses the turbocharged version, and that truck's dry weight is 9800 lbs. It takes about 26 seconds to get from 0-50 MPH. It's a fairly decent engine, but, like others have said, no CTD. In the HMMWV, the turbo version currently produced has 190 HP, the NA only 160. HMMWVs use 4L80E transmissions.

 

[Jeepstang]

I am very familiar with these engines and trucks

I just sold a 1995 Suburban 6. 5 we got mine up to 320 hp and over 500 ft lbs or torque with bolt ons honestly it felt like it had more pep than my new 6. 7 truck and got almost double the mpg 23 was it's best. they have a bad rep because of the pump mounted drivers would overheat because of a bad location they make kits to move it far away from heat and the cooling system should be upgraded to the 97 and newer with the dual flow thermostat and high volume water pump to prevent head cavitations and the harmonic balancer should be replaced every 100k other than that they are good engines in my opinion my truck had 273k on it. Heath Diesel is a great source for upgrades for this engine. it is no cummins but it can be made reliable i had a gas 350 truck before the suburban it was a 1994 and had half the towing power of the 6. 5

 

[JFlagg]

Dad has a '94 Chevy 1500 pickup with the 6. 5 auto. It's no cummins by far, but he has 190k on it and it will still out pull the same truck with a 350 in it. Better mileage as well. Just keep it plugged in when it's cold. Plan to get the relocation kit for the electronics module that is mounted directly above and between the heads. It does not like to get hot.

I second that, they definitely don't like the heat. In Iraq our 1114's were actually pretty reliable as long as you kept them running. We usually left ours on the whole day... If you shut them off when it was 130 outside they wouldn't start back up, had to pour water on the motor between the heads. I wasn't familiar with the motor, so I didn't know what we were cooling off, but it always worked. She would start right back up. Though, like everyone else is saying, "they're no Cummins"



I have heard they make great fuel mileage also, 20+ mpg... .

 

[Moose Truck]

More Hijacking

Plan to get the relocation kit for the electronics module that is mounted directly above and between the heads. It does not like to get hot.

To Bad someone has not came up with a kit for the VP44's module!!!!



Moose

 

[abrankod]

I have a 99 burb K2500 with just over 105k on the clock, and overall its been a rock solid reliable machine. The only issue I've ever had with it is, as people have already mentioned, the fuel control amplifier module, which in Stanadyne's infinite wisdom is a 200W amplifier which heatsinks to the fuel supply; which in theory is great, if you always keep the tank near full so that the big tank of fuel can act as a large heat sink/reservoir. This becomes an issue when the vehicle isnt in a fleet that fuels daily. As the fuel level goes down, there is less mass to sink the heat into, and the module kills itself. Relocation onto a large air cooled heatsink and out of the V of the engine makes the module much happier.

Oh one other thing, a lot of the diesel burbs have the wrong fuel caps on them. Non-diesel caps basically stop up the tank and cause the lift pump to work extra hard because it works against a vacuum in the tank.

Other than that, overall the truck runs great! It is no CTD powerwise (well maybe like an old 12Valver, but you'd be surprised at how decent 190HP is.
One other thing to keep in mind is, basically get the concept of bombing out of your mind... 205-215HP is just about the best possible power to get out of these engines, and thats pushing it. They are simply not built to be power monsters, but more sedate but reliable motors. Many school vans we see in service are well into the 250k range on their original motor, and they run just fine.

Oh, one last thing, first thing you should do is replace the glowplugs, on just about every diesel burb i've ever seen, one or more dont work. This can cause hard starting as well as white smoke when cold.

-Dan

 

[TFucili]

I've seen a few snap the snout off of the crankshaft clean as a whistle at the front main. These were not high mileage engines and were not abused, hydrolocked, etc.

 

[juicedcummins]

I wrenched on them for a bit and also owned 4 over the years. The 6. 5 is a money pit and a good engine to stay away from.



92-93 bad headgaskets, head and rotor trouble on the 4911 pumps

94-99 bad headgaskets till late 97 ,pmd probs

99 bad blocks [would crack internally and put antifreze into the oil]

92-99 oil cooler lines

 

[Jdonoghue]

I've seen a few snap the snout off of the crankshaft clean as a whistle at the front main. These were not high mileage engines and were not abused, hydrolocked, etc.

I would think that that problem would be caused by a bad harmonic balancer. GM had the weird idea of making a harmonic damper out of a pulley - instead of having a metal ring (that drives nothing) with rubber between it and the center part, they decided to turn the ring (balancing weight part of the assembly) into the pulley itself. This means that the driving force for the belt and accessories is transmitted through the large rubber area of the balancer assembly. That, and the fact the rubber area is rather large and exposed to the elements, causes it to deteriorate rapidly. I know too much about these things - they are nearly identical to the damper/balancer assembly used on the old 4. 3 L V-6 Oldsmobile diesel, which was famous for snapping crankshafts, because of the rubber tearing out of the balancer when it deteriorated. When the rubber goes south, the pulley will stay together and appear to be functioning normally. You can only tell it's bad if you get in there and inspect it carefully.

 

[DogDiesel]

Re: JFlagg and water pour

I owned and drove a 6. 2L or 6. 5 from 81 to 02, then dropped a Cummins to replace a 5. 9L. Nearly 100K later, still grinning. Guess my opinion.



After several tours as a maintainer in Iraq, the problems you describe below really are not a 6. 2 or 6. 5L topic. :-{} It is a rotary injection pump and thin JP-8 fuel vs diesel #2. (Standadyne Roosamaster is the culprit here not GM) Every rotary pump in that heat will give you the same problem, whether it is on a HMMWV, a cummins 5. 9 in a forklift, a Lucas, a Mimmec, a Bosche, or you name the pump or engine, JP-8 will not start in high temps in a rotary injection pumps. Pour water over the rear cam low pressure fuel pump and the tolorances are returned close enough to fire up and run. We had to replace the entire series of forklift 5. 9L engines with rotary pumps with 5. 9L ENGINES with in-line P-7100 type pumps because of the JP-8. Rotary pumps and Jp-8 fuel do not like temps over 110-fahrenheight. No affect on inline pumps.



"... second that, they definitely don't like the heat. In Iraq our 1114's were actually pretty reliable as long as you kept them running. We usually left ours on the whole day... If you shut them off when it was 130 outside they wouldn't start back up, had to pour water on the motor between the heads. I wasn't familiar with the motor, so I didn't know what we were cooling off, but it always worked. She would start right back up. Though, like everyone else is saying, "they're no Cummins". .

 

[Yo Hoot]

Don't use it to work and you'll be fine. They like to run hot when loaded.

 

[DWest]

They run hot because?

They are designed with a 22 to 1 compression ratio so high boost and fuel levels = high EGT's. Mine would start in -25 weather with just the glow plugs but with a Hypertech chip it would blow past 1300 degrees in no time. It was fun to drive and the 4L80 sure seemed superior to my 47re. Was light weight in the 1/2 ton and very fast, Jusy not in the same class as the Cummins. DW

 

[EKlem]

I had a '94 with the 6. 5. Even with the relocation kit, I went through 3 injection pumps before I had had enough. The first one went at 140k which seemed to be in line with what all of the other owners I talked to said. The second and third I believe were due to it being very sensitive to fuel. One had a bunch of water in the tank when it died and the other died running winter fuel with 80% kero(low lubricity). The truck was actually pretty good with the exception of the injection pump. The engine was definitely starting to get a little tired at 180k when I sold it but it definitely had some life left in it. I would say that the truck minus engine was at least as good as my dodge. The reason that I sold it was that I didn't trust it.

 

[Wyomingcowboy]

I had a '94 3/4 Ton with the 6. 5 in it. I put about 70k and it had 190K+ when I sold it. I got about 16mpg goin 60 bcause of the low gears. Needed an injection pump at about 175k but no other engine isues. The 4L80E auto was junk and went through 3 of them. True it is NO cummins, but if the price is right why not?!?!

It DID NOT like the cold either. plugging it in below freezing is a MUST.

(I actually have a leftover transfer case also... if you should ever need one)

 

[surfbeetle]

I guess that I better chime in on this one, the cheaper you can get it the better, 'cause you will need the money you are saving for repairs... I have owned my suburban half the time of my Dodge and have spent twice the money maintaining it. Mine has had SEVEN injection pumps. What has made a huge difference on mine was to add an external water separator in addition to the factory fuel/water separtor. The Diesel Page for the 6. 2L, 6. 5L, and Duramax 6600 (6. 6L) GM Chevrolet and GMC diesel engines. is the place to go for 6. 5 info. Also take your vin into a chevy dealer and see if the service writer will run the service history.

 

[nickleinonen]

if i had the space and/or money, i would get a 6. 5td 'burb. . 1500's have an egr system and cat. . the 2500's just have the cat. . if you unplug the egr, you will get a check engine light, but no effect on the engine power. . i blocked off mine with a solid gasket on my former 97 tahoe 6. 5td, and pulled the check engine light bulb from the dash... they don't sound too bad straight piped...