Secondary fuel filtration and additives

[luvthesmellofdiesel]

Okay, I have read the hundreds of posts regarding secondary fuel filtration and fuel additives. I have done some research on additives as well. I have also called nearly every Chevrolet dealer in town to find out the consensus on using a secondary fuel filtration system and fuel additives as well as information about injector failures.

What I would like to know is whether I really should install a secondary fuel filtration system (such as the one offered from Kennedy Diesel) or not? And also whether I should run an additive (such as TPPF) or not?

I consider myself a regular daily driver who takes my truck on roadtrips (I don't fly anywhere, so I always drive). I'll put about 20K miles on it per year (or less). I try to use "good" fuel but since there is no way to know where good fuel is, that's impossible. I try to buy from the same stations (use truck stops when out of town as much as possible), don't get fuel when the refueling truck is there, don't stop at the mom & pop's etc...

But the real question is: How are we (the average Joe owners of these) supposed to make the right educated decisions on whether to make this modification (adding a secondary fuel filter) and do something GM tells us specifically not to do (use an additive)?

When I asked the service folks at the dealers I called about the secondary fuel filtration systems, their responses were mixed. One guy said it would probably be ok, all the rest stated "word for word" that if I were to come in for warranty service and they saw this, it could cause me problems (and I know it would). Now I know that adding a secondary fuel filter should not cause an injector to wear, and from what I have read, it sounds like it shouldn't wear out the injector pump (since there is no lift pump), so I am not afraid to do this technically.

But what I don't want is to have to go into the dealer sometime in the future with the SES light on and a failing injector having them tell me that it's my fault because I have an aftermarket filtration system on my truck. I don't trust dealerships AT ALL. They are obviously under pressure to keep warranty costs down associated with the injectors. Anything they can do to cut warranty costs, they will. I don't like hiring lawyers and such to get my truck fixed either.

With regards to fuel additives, the verdict was unanimous: They all said to NOT do this and that it would definitely void my warranty. I obviously wouldn't tell them I used one. I am not a complete moron. One even went on and on about how everytime someone comes in with a fuel delivery related problem on a diesel, they take a fuel sample and send it to "their lab" for analysis and that if a fuel additive is found (and they'll find it), the warranty is history. This sounds like a load of BS to me..

Also, I asked about if this was a common problem. Each said, no not really, it's not an epidemic. However, each had a similar story to tell (wonder if the story is given to them by GM) regarding trucks they have seen come in all dirty from a "construction site" with "high mileage" that clearly haven't been taken care of and they had injector failure. I interrupted to ask what they meant by "high mileage" to which the responses were 70-80K miles! Now that's NOT high mileage, sorry...

So, what gives? I either do something that will likely void my warranty knowing that it will protect my vehicle and make it last longer, or I do what GM says and basically let my engine wear out faster, and replace fuel injectors when it has "high mileage" at 70K miles or so.

What do you recommend for all of us common folks to do? I want my truck to last and not have to buy a set of 8 fuel injectors at $500 a pop when it reaches the 100,000 mile mark when it's out of warranty.

Thanks,
Tim White

[Kennedy]

I think that the concensus of Diesel Page members would be that the average DP member knows significantly more about the Duramax than the average dealer :eek: ...


Additives:

There is typically NO SUCH THING as "anadditized" diesel out there. Most vendors use some form of treatment. The thing to stay away from is alcohols, and gasoline. These are really the only things that could hang you up.

Additional filtration:

While it may take time to eliminate an auxilliary filter as a cause of a fuel system related problem, they can be quite easily reverted to stock or bypassed. Furthermore, if one were to have a fuel related problem, the FIRST course of action would be to measure restriction at the factory supplied test port. If excessive restriction is indicated, the filters shoul;d be changed before proceeding. If the change in filters does not rectify this, then one would eliminate the auxillairy unit from the system to rule this out.

As for an auxilliary filter CAUSING damage. there is really nothing that can add dirt to the fuel except hose/fittings/hardware. I have addressed this by anodizing my mounting plates, electropolishing the machined nipples, and using a filter with an internal seal to the thread on post.

[luvthesmellofdiesel]

Thanks for the information. I, too, believe that the average Duramax owner knows more about their truck than the dealer. I have rarely trusted a dealer for repairs unless it's under warranty and I have to use them. :-(

What this translates to is that I believe most of what I read on this forum and distrust what the dealer folks say when there is conflict. However, when it comes to voiding warranties, they will do it if they can get away with it.

I realized I can do all the reading and calling I want but in the end, the bottom line is that I have to make my own educated decision as to how best take care of my vehicle and I think the right answer is to use a good fuel additive and a secondary fuel filtration system even though GM says not to. I think they're wrong.

Thanks,
Tim White