New Diesel,

I have heard from a friend who is a trucker that the diesel that we buy is gong to change and will not be good for engines older than 1994.

Can any one tell me what they have heard and what we can do to maintain our older diesel coach engines without spending a fortune?

Thanks,

Jeff

All I can say is that is the first time I have ever heard of that. I can't imagine the oil industry making all pre-94 engines obsolete.

"diesel that we buy is gong to change and will not be good for engines older than 1994."

This is known as "an urban myth", i.e., a lie or halftruth that is retold so often it starts to be believed. My Austin-area neighbor Willie Nelson (Dave knows him well from the Armadillo World Headquarters music scene) has invested in BIODIESEL fuel- that's perhaps the basis for this myth. We oil bidness guys aren't going to take advantage of you poor guys with pre-'94 vehicles.

quote:

Originally posted by jefflarsen:
I have heard from a friend who is a trucker that the diesel that we buy is going to change...

That is the only part of the statement that is really true. (i.e. a halftruth)

quote:

Originally posted by jefflarsen:
...and will not be good for engines older than 1994.

What we can do to maintain our older diesel coach engines without spending a fortune?

The sky is not falling. Do not be alarmed. Most of what I've been told really won't affect the vast majority of us.

quote:

Originally posted by jefflarsen:
Can any one tell me what they have heard?

What is really going on out there? Will it affect me?

Below is information that was a result of a casual conversation that I have had with some of the tanker farms and storage depots that I service in my area.

In a few older diesel engines fuel injector pump seals can be affected by the levels of sulfur in the diesel. Pump seals could shrink when those levels decline.

The combined effect of seal shrinking from lower sulphur diesel and normal seal ageing can result in leaks in the fuel injector pump seals.

The most likely pumps to be effected are the rotary pumps and direct inline injection pumps. Like on the Cummins 5.9L, 8.3L, GM 6.2, 6.5 & Cat 3208 motors. The 8.2L should not notice it as the injectors are fired off of cam shaft action.

So what does this mean to me? Don't panic. The diesel fuel formula has been changed in the past. The manufactures have made extra pump seals for the older motor. I have been told that the new seals for the pumps are slightly better then the older seals and that most of the older motors will not need the seals replaced.

Right now the theroy is being floated that about 5-10% of these older pumps could start to leak. It will start out as a slow drip that could get worse. The correct course of action will be to have your injector pump rebuilt or have a seal kit installed.

Not all markets will have the new fuel right away. There is a rollout that will take time. The lower sulfur fuel will be pushed hard in the metro area first.

Recommendations: Buy your fuel outside of the major markets. See what happens in the real world first. Remember that there is a repair. Your coaches are not going to be useless.

I am not a chemist but believe the statments that I just left. Of course the real world will tell. There are some companies using this fuel in some of the major metro areas (test bed) with little ill effect.

---

I checked the Chevron site and found this. It may put some peoples mind at ease. It's about a 1/3 of the way down the page.

Will low sulfur diesel or low aromatics diesel cause fuel system leaks? The introduction of low sulfur diesel for on-road use in the U.S. was accompanied by fuel system leaks in a very small percentage of vehicles. Investigations into the cause of these leaks suggest that the problem was linked to the change in the aromatics content of the fuel and to seal material and age.

Diesel fuel systems contain "O-rings" and other parts made of elastomeric materials. These elastomers swell slightly when they contact diesel fuel, because they absorb aromatic compounds from the fuel. Exposure to a fuel with a lower aromatics content will result in some of the absorbed aromatics being leached out, causing the elastomer to shrink towards its original size. If the elastomer is still pliable, this shrinkage will not cause a leak. However, if age or service at higher-than-normal temperatures has caused the elastomer to loose its elasticity, a leak could occur. Vehicle owners should be aware that elastomeric parts have finite lives and should be replaced as necessary.

By itself, low sulfur or low aromatics diesel fuel does not cause fuel system leaks. They are caused by the combination of a change from higher to lower aromatics fuel and aged O-rings and elastomeric parts that have lost their elasticity.

BillNY, is this a higher standard than "low-sulfur" diesel? I did see a reference to "ultra-low sulfur" on one website. We've been using low-sulfur in Canada since I was a toddler, or so it seems, and I've driven (among a number of other pre-1993 rigs) a 1970-something slab-cab kenworth with a "hummin-Cummins" that didn't suffer any ill effects from reduced sulfur fuel. Maybe people are expecting the same sort of problems as the lead to no-lead change?

quote:

Originally posted by playerslight77:
BillNY, is this a higher standard than "low-sulfur" diesel? I did see a reference to "ultra-low sulfur" on one website.

I think it was back in 94 we went to the first stage of low sulfer at less then 500ppm. It's going to the ultra low 15ppm. I think I remember hearing 5ppm instead or something like that for the new particle trap exhaust.

You'll like this. Starting in 2007 most OEM mfg will install these exhaust particle traps to catch the exhaust burn off. If those rigs get the regular stuff the exhaust system could catch fire or even plug up. There's even a regeneration cycle that these exhaust are suppose to go thru to keep them clean. (like a water softener)

At about 100,000 miles you bring your truck back into the dealership and have the particle trap changed out. There is a core charge on these new exhaust systems and they have some pretty exotic metal in the trap to do this job.

Wild stuff to say the least. Now I'll be doing service calls to check for low power and find that the exhaust is plugged up. It's going to be a new ball game for sure! The MPG's are suppose to suffer as a result of this.

Time will tell. Expect to see a lot more lubricity type of formulas to add to your diesel fuel tanks. I would recommend that if you can find it buy some and add per instructions on the bottle. Let's let other people be the testers until more is know. (i.e. real world results.)

Ps. I also remember hearing something about 50ppm but for the life of me I can't say for sure what that part of the conversation was about.

Thanks for the response, BillNY, that makes sense.