who has owned a 90's Chevy/GMC 6.5 TD?

[jeep-N-montero]

I'm looking at a very clean 2 owner 1995 K2500 with 5 speed manual for a tow rig, "F" VIN 3/4 ton with only 139k on the body and 80k on the engine, paint looks new and the interior is immaculate. I am aware of the cooling system upgrade using the 97-99 parts and that will be the first thing to get done along with relocating the PMD. Also know that they are a bit low on power when compared to the 12 valve or 7.3 of the same vintage, but given I will never tow more than 7k pounds it will do just fine with a few minor upgrades.

So, anything I'm missing and how have you liked yours?

 

[myershorsepower]

Black ZJ
I don't have much info for you on the 6.5, But maybe DMT may chime in, he has a '94 suburban with 6.5, looks like he is from Utah also.

 

[Christian P.]

I did. You can see my thread somewhere on the forum, I only had one issue with the PMD (it died). Did the relocation and bingo.

I was actually surprised by it, I liked it more than I expected. Power was good and fuel mileage very acceptable, even when carrying the heavy BigFoot camper.

The main issue for us is that we found it very noisy.

 

[jeep-N-montero]

I did. You can see my thread somewhere on the forum, I only had one issue with the PMD (it died). Did the relocation and bingo.

I was actually surprised by it, I liked it more than I expected. Power was good and fuel mileage very acceptable, even when carrying the heavy BigFoot camper.

The main issue for us is that we found it very noisy.

I'm sure it will be quiet compared to driving a slightly hopped up V8 breathing through a 3in exhaust with solid mounts and no real muffler rolling on 35x12.50 KM2's. I hope with the 5 speed manual the 6.5 TD will average 19mpg empty, maybe 20-21 after a few upgrades, and when towing the Jeep it will likely still get better mpg than driving the Jeep to the trail.

 

[greengreer]

A good stock motor can turn out 22-23 mpg depending on tire size and gearing. You are right on about the dual thermostat upgrade, however 97+ trucks have a few more differences such as oil squirters and stronger front differentials.

That being said, I dont think the differences are noticeable under normal use.

I like my 6.5, injectors and other maintenance parts are a lot cheaper than most diesels. It has plenty of power for what I do, and you always have the option to change out the electric ip for mechanical if you desire simplicity.

The nv4500 is an awesome transmission, although some early ones had a dual mass flywheel that is a high dollar replacement. Had a buddy that got rid of his automatic 6.5 (still has a 5spd one) but I suspect a transmission reprogram would've changed his mind.
Pmd relocate, upgrade oil cooler lines, and inspect/replace balancer. Those are the most important 6.5 specific, other than that make sure your fuel filters are clean and your lift pump and ops are in working condition.

Biggest bang for the buck upgrade is exhaust, then maybe look for a k47 airbox.

Goodluck!

 

[peneumbra]

I have one in my '94 3500HD; the milage isn't great, but this is a heavy 4x4 vehicle with 4:88s. Backed with a 4L80E auto transmission.

 

[jeep-N-montero]

A good stock motor can turn out 22-23 mpg depending on tire size and gearing. You are right on about the dual thermostat upgrade, however 97+ trucks have a few more differences such as oil squirters and stronger front differentials.

That being said, I dont think the differences are noticeable under normal use.

I like my 6.5, injectors and other maintenance parts are a lot cheaper than most diesels. It has plenty of power for what I do, and you always have the option to change out the electric ip for mechanical if you desire simplicity.

The nv4500 is an awesome transmission, although some early ones had a dual mass flywheel that is a high dollar replacement. Had a buddy that got rid of his automatic 6.5 (still has a 5spd one) but I suspect a transmission reprogram would've changed his mind.
Pmd relocate, upgrade oil cooler lines, and inspect/replace balancer. Those are the most important 6.5 specific, other than that make sure your fuel filters are clean and your lift pump and ops are in working condition.

Biggest bang for the buck upgrade is exhaust, then maybe look for a k47 airbox.

Goodluck!

What's a "k47" air box?

 

[greengreer]

96+ IIRC. They used a cylindrical filter instead of flat panel. I've got a k&n element in mine but a s&b cold air intake awaiting installation. I will be interested to see if there's any noticeable difference

 

[jeep-N-montero]

96+ IIRC. They used a cylindrical filter instead of flat panel. I've got a k&n element in mine but a s&b cold air intake awaiting installation. I will be interested to see if there's any noticeable difference

When I spoke to Bill at Heath diesel power the other day he mentioned that most of the aftermarket "intakes" are not all that great and to just use an OEM filter, I inquired about the oil free AFE filters and he was not familiar with them yet. I will never use a k&n or other filters you have to oil ever again, too many close calls with the Jeep and having sensors die prematurely because of poor filtration, but I will be trying the AFE Pro Dry filter on the 6.5, maybe even try their entire intake setup http://www.ebay.com/itm/aFe-MagnumF...Parts_Accessories&hash=item51a613f203&vxp=mtr

 

[greengreer]

I can't recommend that intake, it does not seem to have any sort of box around it to prevent it from drawing hot air from under the hood instead of cool air from the fender.
S&b makes the only intake proven to increase power. IIRC Bill heath used to sell em and had a part in designing them too.
That being said , the only reason I have one is because I got it used for cheap. No way I would spend that money for a new one, I would have my Stock k47 and the s&b oiled filter(they make both dry and oiled).
Cheapest and most effective solution is a junkyard k47 box and good quality paper filter, that will flow plenty of air for a 6.5 and be easy to get parts for. Also quieter than aftermarket.
IMO exhaust is the biggest restriction, look into diamondeye.
The stock turbo can be a restriction too depending on what you want out of it. They make great power early with the stock vacuum wastegate

 

[grandpa]

I have a 1995 K1500 Suburban with the 6.5 TD and 330k+ miles. Runs very well.

 

[BurbanAZ]

i have a 94 k2500 suburban with a 6.5td and around 200k, i really like it. Its got a few things that i need to fix from the previous owner but overall its solid. The nice thing i found also is that you can get a military take out with very low mileage that was made around 08, so it has all the upgrades and fixes alot of the issues the 6.5 has in the older models, for like 2500 bucks, which isnt bad for an almost new engine. Most of the reviews ive read on the take outs have been really good. Also im getting close to 20mpg which is nice, and pulls wells.

 

[Willy G]

Is it a six lug or eight lug. I know it sounds funny but my buddy had a 92 6.2 with six lug axles, and 3/4 ton badges, if it is only a six lug I will not recommened towing with it, but the fact that I dogged him in a small stoplight drag race, in my 350 suburbMwas just something that proved that its not the best of motors NA, BUT before he sold it, he converted it to a 6.5 with a banks bank turbo, that thing came alive. had 225,000 when he sold it, and actually turned around and beat me in the same still race.

A stock 6.5 with a nv4500 will last forever towing or just as long as you do the general mantanice

As a referance this truck was built as a joke, and just, kind of a test of our skills

 

[jeep-N-montero]

Is it a six lug or eight lug. I know it sounds funny but my buddy had a 92 6.2 with six lug axles, and 3/4 ton badges, if it is only a six lug I will not recommened towing with it, but the fact that I dogged him in a small stoplight drag race, in my 350 suburbMwas just something that proved that its not the best of motors NA, BUT before he sold it, he converted it to a 6.5 with a banks bank turbo, that thing came alive. had 225,000 when he sold it, and actually turned around and beat me in the same still race.

A stock 6.5 with a nv4500 will last forever towing or just as long as you do the general mantanice

As a referance this truck was built as a joke, and just, kind of a test of our skills

It's an "F" code with 8 lugs, so it is the better chassis of the bunch.

 

[Willy G]

Got it, I'm just a driver not too much of a mechanic :smiley_drive: