1999 Chevy K2500 Suburban 6.5 Diesel (Automatic)

[101Volts]

Darn, the fuel tank in mine wasn't that bad when I had it off. Maybe yours sat for some years untouched?

Mostly lately on my end it's been maintenance; I put bolts in the roof stud holes, put silicone around them and have been spraying Fluid Film everywhere that's vulnerable to rust. I think I should replace a few brake lines too. Also changed the oil and filter to Shell T6 5w40 and another Amsoil EaO24. Mileage has likely dropped as the 0w40 was thinner even at operating temperature and now the vehicle feels like it's a little more restrained.

Hypermiling though, nothing much has happened. The biggest thing would be to put side skirting on but maybe I'll put some taller diameter tires on when I need a set.

[101Volts]

Latest reports:

1: Replaced CDR (PCV) Valve as it was leaking oil. Oil usage reduced, I'm not sure if it helps with anything else.

2: Plan to install new Oil Cooler Lines purchased from Lubrication Specialist (linked below,) the stock ones are prone to leaking and blowing due to their design. I read gas versions are like that too but don't know if they are.

97 and Later 6.5TD Oil Cooler Lines: Espar Heater Parts, Diesel Truck Heaters - Lubrication Specialist

3: Still have the Oil Bypass Filter Kit which I also plan to install after installing the lines.

4: Made cardboard template for rear wheel skirting.

5: Planning to make skirting under the side steps after working on the lines and bypass system.

6: Planning to make modifications to the front air dam for better airflow and structural support.

7: Purchased Fuel Additives:

Opti-Lube Boost!: Claims to increase Diesel Fuel's Cetane (ignitability) rating by 7-9 (or 11 if you read the sales brochure) points which quiets the engine, decreases emissions, increases performance and MPG.

Opti-Lube XL: Fuel Lubricity Improver. My engine was built before ULSD Fuel came about and this is supposed to reduce wear on fuel system components.

I haven't tried the fuel additives yet. After overtreating the first time I'll use Boost at the max treat rate and XL near the max treat rate.

Another note: Opti-Lube makes another fuel additive, "XPD" (favorably mentioned in the thread linked below) but it's more of an an all-around additive that doesn't increase cetane or lubricity as much.

http://ecomodder.com/forum/showthrea...ive-26910.html

[deejaaa]

i just use 2 stroke. much cheaper and does the same thing.
BTW, checked mpg: 13.2. timing is too far advanced so will set that tomorrow. most of that was in town.

[oil pan 4]

Vegetable oil is even cheaper than 2 stroke oil and a little bit makes the diesel very oily.

[101Volts]

Latest Reports:

1. Replaced Oil Cooler Lines and Oil Cooler. (Not F.E. related.)

2. Installed Amsoil Universal Dual Bypass Oil Filtration System - still need to stop small leaks. (May increase F.E. slightly as it significantly decreases contaminants in engine oil.)

3. Overtreated with Fuel Additives Opti-Lube Boost and Opti-Lube XL in at this last fill. Too early to tell how the vehicle reacts or if it increases F.E.; although the vehicle sounds quieter I'm not sure why, maybe the additives help or it's a combination of the filtration and additives.

4. Air Dam isn't on the vehicle, I need to modify it; It should turn around the bumper's corners and not be so flimsily attached to the bumper.

5. Drilled vent holes in fuel cap. (May not effect F.E. but should help the lift pump.)

[101Volts]

More reports:

1: I changed the oil to Amsoil Heavy Duty 5w40. This is thicker than Shell T6 5w40 both cold and hot and I may see a slight drop in F.E.; OTOH engine longevity should be greatly increased with this oil and the bypass filtration. (It was a big concern given how many repairs this Suburban's had since purchase.)

2: For the 250 miles I drove with T6 5w40, the Opti-Lube additives and the bypass filter I didn't feel like the fuel efficiency dropped much although the air dam was off. Going up hills at 45 MPH the vehicle felt like it had slightly more power and didn't have to downshift as much; the SG II read slightly higher too.

3: I have better hardware to attach the air dam.

4: On subject of rear wheel skirting, has anyone here made skirting with louvres near the back to move air pressure out of the wheel arch without introducing more pressure?

5: I'm planning on making the wheel skirting easy to remove with a drill; I'll use lock nuts "glued" (not with glue, I don't know the product's name) on to brackets which will attach to the vehicle's already existing screws that hold the plastic wheel arch extensions.

6: I have a dual engine cooling fan out of a 2000 Dodge Caravan w/ the 3.0 engine. I almost feel like it's a joke to ask yet would this be enough to cool the 6.5? I don't feel like it is.

[deejaaa]

cooling needs to be as good as the mech fan or better. think you answered your own question.
no experience on rear skirts but if you look at the big rigs running them you might get an idea.
on a personal note:
i replaced the front brakes. pass side was dragging. at a stop, old brakes, no roll back. new brakes, roll back. IE, less friction. old brakes wore out the inner rotor on pass side. lubed the slide pins and seems to be much better.

[cRiPpLe_rOoStEr]

Originally Posted by 101Volts

I have a dual engine cooling fan out of a 2000 Dodge Caravan w/ the 3.0 engine. I almost feel like it's a joke to ask yet would this be enough to cool the 6.5? I don't feel like it is.

Diesels usually retain more heat by default. Anyway, the most successful references for electric fans with the 6.5 were the dual-fan setup from the Ford Taurus fitted with the 3.8 engine.

[aardvarcus]

I wouldn’t use a caravan fan.

The Mark VIII and Tarus fans get the most publicity for being the “most powerful” electric fans, but for my 6.5L, I am using electric fans from a 1994-1997 Thunderbird/Cougar. The Thunderbird/Cougar just used one fan, I am going to cram two of those fans into my 6.5L radiator. From my research, they are extremely similar to the Mark VIII/Tarus fans but use different blade pitch and electric motors. The result is they move similar amounts of CFM but draw less current. The fans are two speed, so by using two of them I am creating a “three speed” fan controller by having (1) both in series on low (each fan sees 1/2 voltage so 6-7V), (2) both on low (parallel, full 12-14 volts), and (3) both on high (parallel, full 12-14 volts) using relays. I plan cut up and heat weld the fan shrouds to the old engine fan shroud to mount them. From my measurements they will fit, but they may overlap the edges of each other or the radiator a bit. (I just pulled them out of their boxes and started test fitting last week.)

This is very similar to the fan controller/mount I did on my Tacoma, except my Tacoma used two Camry fans and only had two speeds. http://ecomodder.com/forum/showthrea...ler-32368.html

[101Volts]

Originally Posted by deejaaa

cooling needs to be as good as the mech fan or better. think you answered your own question.
no experience on rear skirts but if you look at the big rigs running them you might get an idea.
on a personal note:
i replaced the front brakes. pass side was dragging. at a stop, old brakes, no roll back. new brakes, roll back. IE, less friction. old brakes wore out the inner rotor on pass side. lubed the slide pins and seems to be much better.

Makes sense.

I've looked them up and they vary, I've never seen one with louvres and only one article said "skirting traps air in the arches" so I ponder if that was even correct. If it is I'd like to put louvres on for air to escape but not be brought in.

Good to hear!

Originally Posted by cRiPpLe_rOoStEr

Diesels usually retain more heat by default. Anyway, the most successful references for electric fans with the 6.5 were the dual-fan setup from the Ford Taurus fitted with the 3.8 engine.

I'll keep this in mind, thanks.

Originally Posted by aardvarcus

I wouldn’t use a caravan fan.

The Mark VIII and Tarus fans get the most publicity for being the “most powerful” electric fans, but for my 6.5L, I am using electric fans from a 1994-1997 Thunderbird/Cougar. The Thunderbird/Cougar just used one fan, I am going to cram two of those fans into my 6.5L radiator. From my research, they are extremely similar to the Mark VIII/Tarus fans but use different blade pitch and electric motors. The result is they move similar amounts of CFM but draw less current. The fans are two speed, so by using two of them I am creating a “three speed” fan controller by having (1) both in series on low (each fan sees 1/2 voltage so 6-7V), (2) both on low (parallel, full 12-14 volts), and (3) both on high (parallel, full 12-14 volts) using relays. I plan cut up and heat weld the fan shrouds to the old engine fan shroud to mount them. From my measurements they will fit, but they may overlap the edges of each other or the radiator a bit. (I just pulled them out of their boxes and started test fitting last week.)

This is very similar to the fan controller/mount I did on my Tacoma, except my Tacoma used two Camry fans and only had two speeds. http://ecomodder.com/forum/showthrea...ler-32368.html

Good to hear this, thanks. Will you be making a similar thread for your 6.5? I don't suppose it's necessary, just wondering.