6.5L preventative maintenance

[RLC2020]

Truck has 230k miles on it. PMD has been relocated to the inner fender over the wheel. AFE cone filter/intake pipe. The muffler has been removed - straight pipe all the way out the back. Previous owner(s) did all these mods. I've owned the truck for about a month now, loving it so far. Did an oil change with Rotella T6, cleaned the AFE intake filter and re-oiled it. Now I'm wondering what to do next.

Regarding the harmonic balancer, I'm assuming it's has already been done based on the mileage, but should I replace it anyway as a precaution? I can't see any issue visually and it's not making any noise or wobbling. I know these are an engine killer if they let go. Would I have some warning first? Thoughts?

Any other things I should be inspecting or replacing at this time? I have a new fuel filter on standby but the truck seems to start and run great. AC worked after replacing the orifice tube and charging it a month ago, now it's blowing warm. I'm guessing it has a leak so I have a seal kit on order.

any suggestions would be greatly appreciated. This is going to be my boat ramp tow rig and weekend ride. I have another Sub and an F250 I'd use for heavy towing.

 

[95burban]

Not really 6.5 related but diesels in general, especially older diesels.

Run a fuel conditioner, like power service in the gray bottle. It’s helps injectors. Newer diesel fuel has less sulfur and is developed for new diesel engines so adding an additive helps restore what was taken out.


Frequent oil changes, older diesels will have more blow by that will contaminate the oil quicker or add an external oil filter

Rotela is great oil, you can save money buy using generic diesel oil since you will be changing it more often.

Add extra filters for oil and fuel

I’ve had several high mileage Cummins and powerstrokes, its always worked for me.

 

[RLC2020]

Thank you, I forgot to mention that I run the gray power service. I dosed the first tank heavily, I also added a bit of 2 stroke oil as well. I used to do that with my 6.2 sub, figured it couldn't hurt in the 6.5l.

I'm digging your wheels btw: A set of those would look great on my 2wd '97.

 

[Schurkey]

Truck has 230k miles on it. PMD has been relocated to the inner fender over the wheel. AFE cone filter/intake pipe. The muffler has been removed - straight pipe all the way out the back. Previous owner(s) did all these mods.... ...cleaned the AFE intake filter and re-oiled it.

Obnoxiously-loud vehicles incentivize politicians to restrict vehicle mods. The last thing we need is dirtbag politicians and appointed idiots on the warpath, looking to stop us from responsibly modifying our vehicles. GET A MUFFLER, if not a muffler and catalyst.

Cleaning an oiled-gauze filter is pretty-much the worst thing you can do to it, unless it's so caked with dirt that a) you can't see the pleats any more, or b) the air filter restriction indicator is proving that the air filter is restrictive. Oiled-gauze filters are more effective when they've got dirt already on them. The captured dirt becomes part of the filter media, stopping even more dirt. As soon as you clean 'em, they're not as effective any more.

AC worked after replacing the orifice tube and charging it a month ago, now it's blowing warm. I'm guessing it has a leak so I have a seal kit on order.

You need real diagnosis to find the actual leak(s). Replacing seals is a great start...but only a start. Seal kit won't fix a leaking condenser or evaporator. Won't fix a leaking compressor, or hoses.

 

[95burban]

Technically the turbo is a muffler, highly doubt it had a cat from GM. I guarantee that truck isn’t any louder than Billy bobs truck with flows and echo tips or frat boys mustang that his parents bought.

 

[RLC2020]

Obnoxiously-loud vehicles incentivize politicians to restrict vehicle mods. The last thing we need is dirtbag politicians and appointed idiots on the warpath, looking to stop us from responsibly modifying our vehicles. GET A MUFFLER, if not a muffler and catalyst.

Cleaning an oiled-gauze filter is pretty-much the worst thing you can do to it, unless it's so caked with dirt that a) you can't see the pleats any more, or b) the air filter restriction indicator is proving that the air filter is restrictive. Oiled-gauze filters are more effective when they've got dirt already on them. The captured dirt becomes part of the filter media, stopping even more dirt. As soon as you clean 'em, they're not as effective any more.

It's not loud at all, it's a diesel, all the noise comes from under the hood, not out the tailpipe. The turbo blocks 90% of the sound anyway. Removing the restrictive muffler lets the engine breath through the turbo, these 6.5's are choked up from the factory. One of the first recommendations from every source on the 6.5 is to do a straight pipe exhaust. Thanks for the input though. As for a cat, this is a DIESEL. please do some research.

As for your theory on effective air filters, are you suggesting that when purchased new they are terrible and should not be used because they are clean? How is one to find a used one with a century's of dirt on it already so they can have an effective filter? Should we take it out of the box and drive over it in a mud bog for a month before installing it? Your statement is the most nonsensical thing I've ever heard...

 

[Schurkey]

As for a cat, this is a DIESEL. please do some research.

Newer diesels do have catalytic converters, but apparently not in '99.

As for your theory on effective air filters, are you suggesting that when purchased new they are terrible and should not be used because they are clean? How is one to find a used one with a century's of dirt on it already so they can have an effective filter? Should we take it out of the box and drive over it in a mud bog for a month before installing it? Your statement is the most nonsensical thing I've ever heard...

This is NOT "my theory". I learned it by reading the K&N Filters web site years ago. Kinda guessing that K&N knows something about oiled-gauze air filters.

At first, they suggested that dirt had to be 1/8" thick before cleaning was needed. With an eighth-inch of accumulated oily dirt, it'd be tough to see the individual pleats of the filter media. If significant (but less than 1/8") dirt built-up, it was wise to add a little more clean filter oil to the clean side of the filter, as the accumulated dirt would wick oil from the cotton gauze, and the oiled dirt attracted more dirt.

Somewhat later, the "1/8 inch of accumulated dirt" advice was replaced by "look at your filter restriction indicator, clean only when it shows restriction."

They're promoting "up to" 50K miles for stock replacement filters, and "up to" 100,000 miles for bigass aftermarket-style cone filters. But if you dig into their web site you'd find:
www.knfilters.com/filterminder.htm

Filter Minder® Gauges

Factory direct K&N replacement air filters, air intakes, oil filters & cabin filters. KNFilters.com - the official site for performance filtration products.

www.knfilters.com

Filter Minder® Gauges

You must be registered for see images attach

Air filter service indicator that monitors air filter restriction and indicates when the air filter should be serviced. As the air filter gets dirty, the yellow position indicator moves in the clear window of the service indicator and locks at the highest point. It can be read even after the engine is turned off. The air filter should not be cleaned until the yellow position indicator reaches the red zone. Reset the position of the indicator to zero by pushing the yellow reset at the end of the service indicator.


Important Notes:
Air filters typically plug very slowly, and initial filter restriction may not occur until 50,000 miles or more depending on operating conditions. Diesel applications and off-road use will generally require more frequent cleanings or maintenance.


Most applications will show no air filter restriction on the service indicator with a new K&N Air Filter. There may be rare instances where the position indicator could move in the window even with a new air filter. This could result from high air flow engine requirements, or from operating in high humidity or rain. Do not be alarmed if the clean air filter restriction exceeds the initial calibration of the service indicator. The air filter should not be cleaned until the yellow position indicator reaches the red zone.


K&N Air filters become more efficient at stopping dirt as they build a dust film. It is recommended that the air filter be cleaned only when the air filter service indicator reaches the red zone.

(My emphasis)

Fact remains--up to the point of creating restriction, oiled gauze alone, is not as effective (K&N uses the word "efficient") as oiled gauze plus accumulated oiled dirt at trapping more dirt.

If they are "more efficient" at trapping dirt when they've got accumulated dirt on them, they're "less efficient" at trapping dirt after you clean the accumulated dirt off of them. DON'T CLEAN AN OILED-GAUZE AIR FILTER MORE OFTEN THAN NEEDED.


Feel free to contact K&N and tell them they're providing "nonsense" advice. Between you and K&N, I know which one is providing "nonsense".

 

[smokymtn65]

My 95 came with a "soot" trap. I t is a 1500. It runs a 4in exhaust with ultra flow style muffle sound sweet at idle deep rumble. No drone on the highway.

 

[BNielsen]

6.5 NEWBIES - *START HERE*
I treated this like the bible, helped me a lot when I first got my Turtle Diesel
Check all your fluids, 6.5s especially like a good fuel additive to improve lubricity. Check your balancer and crank pulley, if there's wear and tear replace them! You can grab the belt and if the crank pulley has any wear you'll be able to twist it, HB will show some rubber cracking.

Make sure your cooling system is up to *****, these trucks are super sensitive to heat, mine is going to more than likely get the whole cooling system redone at some point. Is your truck dual or single t-stat?

Check your turbo and CDR valve, replace or clean if needed, those crappy oiled filters belong in the garbage in my opinion. Check vacuum pump or delete, whatever you feel like is the right course.
BATTERY CABLES, BATTERIES, and STARTER! These motors are notorious for breaking the ears off the block, so make sure you've got decent batteries and good cables. There's a brace that keeps the starter from breaking, make sure you've got it, Quadstar sells a replacement if yours is missing.

My 2000 K3500 is pretty much stock aside from a vacuum pump delete and a straight pipe. It's still got the factory crossover and downpipe, but at some point the muffler was deleted and someone welded on a 4" straight pipe. My straight-piped 6.5L is quieter than my 7.4L with glasspacks (WORST THING I'VE EVER DONE)
I'm trying to bribe my buddy into make me a 3.5" downpipe for when I swap an HX35 on, between a full 4" exhaust with a larger crossover coming off a bigger turbo, tune and lift pump the truck should motor fine, it's been pretty damn reliable for something I bought out of a salvage yard.

Just follow that DieselPlace link and you'll be alright.

 

[Erik the Awful]

I clean the K&N filter in my Mustang about every 20k miles. If it weren't such a pain in the butt to get clean I'd do it more often. Sure, a layer of dirt might offer "more" filtration, but at some point it's just a layer of trash on your filter. I'm pretty sure a clean, oiled K&N is still more effective than a plain paper element. No need to make rocket science out of it. I'm sure there's an engineer somewhere who will tell you there's a torque spec on the wing nut on your air cleaner.