need advice on how to maintain my injectors

[chesapeakechuck]

I just purchased a 2003 GMC 4X4 with the 6.6 liter lb7 duramax engine. The truck has 92K on it and the dealership (gmc) is replacing all 8 injectors prior to my taking delivery of the truck (long story here--I drove over 500 miles to test drive the druck and when I did, I found that the vehicle has 6 bad injectors). Anyway, I never have owned a diesel before and I would like to know what I should do in terms of preventative maintenance to ensure some longevity out of the new injectors. I know the old injectors were prone to failure and I have been told that the injectors that are being put in now are upgraded ones (whatever that means).

Can someone recommend a good fuel filter that goes down to 2 microns? How often should I change this out? How often should I change the oil in the crank out and should I use synthetic or not?

I appologize for these questions as I am sure they have probably been addressed here elsewhere a thousand times over, but I am new to the forum and new to diesel engines. Any help or suggestions would be GREATLY appreciated.

[CoyleJR]

chesapeakechuck

I would start by calling Kennedy Diesel and talk to John. He sells a two micron filter kit and a boost pump that are designed to increase the injector life. Kennedy Diesel is listed in the advertiser section of The Diesel Page. You could do a DP search and read past posts on the subject.

[chesapeakechuck]

I was just looking at the Kennedy site and will pick up a filter and pump. I don't want to see the same thing happen to the new injectors that happened to the old ones. I know how important clean fuel is for these engines. I appreciate your reply.

[More Power]

The Duramax has a 7500 mile service interval for the engine oil. I'd consider that a light-duty service interval (non towing). Cut it in half when the truck is used for heavy towing.

Use synthetic if you plan to own the same truck for more than 5 years or more than another 100k miles. If you trade every 3 years, you're just helping the next owner. Or, if you live in Fairbanks AK or in Yellowknife, a synthetic would help the engine start during the winter. Or, if you live in Texas/AZ, and tow heavy during the hottest months, a synthetic would be recommended.

For everyone else a high quality API diesel-rated petroleum oil is just fine.

Jim

[chesapeakechuck]

Thanks, Jim....No, no fairbanks for me-----I did my undergraduate degree up in Fairbanks 20 years ago and I still have not recovered from the cold winters there....I'll take the Southern California desert weather to that anyday. I will plan on changing the oil out every 4K or so...I am not going to do any real heavy towing, but I will be towing my sportfishing boat the 140 mile distance from Palm Springs to San Diego frequently...It only weights maybe 5K, so it should be a breeze to tow behind the GMC. At the very least, I am going to install a secondary fuel filter from Kennedy and hope for the best. I hope the truck gives me some trouble free mileage.

[More Power]

Thanks, Jim....No, no fairbanks for me-----I did my undergraduate degree up in Fairbanks 20 years ago and I still have not recovered from the cold winters there....I'll take the Southern California desert weather to that anyday. I will plan on changing the oil out every 4K or so...I am not going to do any real heavy towing, but I will be towing my sportfishing boat the 140 mile distance from Palm Springs to San Diego frequently...It only weights maybe 5K, so it should be a breeze to tow behind the GMC. At the very least, I am going to install a secondary fuel filter from Kennedy and hope for the best. I hope the truck gives me some trouble free mileage.

The older I get the more I dislike the cold... But then again, I really don't like the hot all that much better. Maybe the snowbirds have something...

For those concerned about injector life, I believe using a commercial diesel fuel treatment that adds additional fuel lubricity is as or more important than additional fuel filtration. Most good fuel treatments include a cetane booster, which helps the engine run more efficiently. Fleet tests have shown that a commercial diesel fuel treatment that includes cetane increases fuel economy just enough to pay for the cost of treatment. However, most individual owners have a hard time seeing it unless they run spreadsheets on fuel economy over the long-term.

If the truck has been serviced regularly before you got it, the engine oil should remain a pretty amber color for as long as 5-6K miles when driven unloaded. I tend to use oil color and time for determining when to change it. Amber or slightly transparent gray motor oil is fine to continue running. Opaque black oil needs to be changed out. It's mostly the soot buildup that determines service interval.

Unlike a gasoline engine, the formation of acids and other corrosive by-products mostly don't exist in used diesel motor oil these days. The removal of sulfur from the fuel has allowed for extended drain intervals as well.

Jim

[richp]

Hi,

A quick question.

I've never used synthetics, and have been quite satisfied with dino Rotella in all my trucks up until now. But now with 75k on my LMM, I'm reconsidering it. I intend on keeping it a lot longer, with a fair amount of towing.

Any issues to consider?

[Kennedy]

My thoughts and recommendations at the close of this Tech Tip:

http://www.kennedydiesel.com/docs/Duramax%20Injector%20Failures.pdf

[More Power]

Hi,

A quick question.

I've never used synthetics, and have been quite satisfied with dino Rotella in all my trucks up until now. But now with 75k on my LMM, I'm reconsidering it. I intend on keeping it a lot longer, with a fair amount of towing.

Any issues to consider?

The compatibility of current synthetics and conventional motor oil precludes problems with switching mid-stream. I use the Shell synthetic because it needs changed but once a year. The long service interval works perfectly fine with the more expensive oil.

Jim

[chesapeakechuck]

One more thing while we are on the topic of my new (used) truck. The truck has 285 BFG's on it. I know this will make my speedometer read erronously. I think I have to get some sort of tuner in order to be able to reprogram it for the larger tire size. Can you make a suggestion as to what you think would be best? I'm on something of a budget, but any recommendation you have would be most greatly appreciated!