Fuel Filters and Injector Cleaner

Mark Scott · March 08, 2009, 11:34:59 AM

I am getting ready to change the fuel filters and change the oil. I was told buy a CAT mechanic when changing both fuel filters to add 50% Seafoam and 50% diesel when putting both fuel filters on. My application is a MCI 102A3 with a 8V92 TA. Thanks in advance for your thoughts. Mark

luvrbus · March 08, 2009, 12:42:00 PM

Mark, all the additives are pretty much snake oil why waste your money on a product DD does not recommend using in their engines clean fuel is hard to beat and a lot cheaper.If you live where algae is a problem us the Seafoam product to solve that. good luck

Sean · March 08, 2009, 05:54:40 PM

Detroit Diesel recommends against adding any additives to fuel in the Series 92 unless you are experiencing gelling.

I recommend you surf over to the Detroit web site and download free publication 7SE270, "Lubricating Oil, Fuel, and Filters," which will tell you everything you need to know about fuel and motor oil in your two-stroke. You can find it on this page:
http://www.detroitdiesel.com/support/on-highway/manuals/lubricants_fuels_coolants/

There is a lot of snake oil out there, and also a lot of myths and urban legends. Even veteran mechanics are not immune.

-Sean
http://ourodyssey.blogspot.com

bigjohnkub · March 09, 2009, 08:33:27 AM

OK, I'm going to stick my 2 cents worth in. I have been a diesel construction mechanic since 1967. I taught diesel engine repair at the Army engineer school at Ft. Belvoir Virginia. All makes of engines use different types of Injection pumps. The in line pumps , such as cat, do not require a lot of lubrication. The rotary types , such as perkins, cav, and others are lubricated by the diesel that goes thru them. Our Gov't has removed the sulphurs from the fuel (is now less than 5 parts per million) which creates lube problems in older engines. You must put in some type lube. Some use auto trans fluid, I don"t because it turns the diesel red. I use diesel treat 2000', which has a LUBRICITY additive. It also is supposed to improve cetane 5 points, boost horsepower, improve mpg5%,disperse WATER, clean injectors, meet Cummings specs., and generally make your wife happy all the time. I believe it does some of these.
It does increases the lubrication, and since it is synthetic, it does not increase smoke. It helps with water. It cost about $8.50 for a bottle to treat 125 gallons. It is a very small price to pay to help my old Detroit. It certainly will not hurt.
I know it will dissolve carbon off injector tips outside the engine. As to whether it will clean injectors in operation, I will bow to Dallas to answer that.
We have always told owners to BUY CLEAN FUEL,KEEP IT CLEAN. The problem at this time is the diesel you buy is sorry. Get some on your hands and it will not be oily.

luvrbus · March 09, 2009, 08:48:56 AM

John, you are dealing with 2 different type systems here the DD is a unit type meaning the fuel flow and the pressure injection and the nozzle are in one unit the others use a injection pump to do that and only a nozzle to inject it in to the chamber.And for what it is worth the 2 strokes ran on kerosene or number one fuel the low sulphur fuel is what the DD 2 strokes folks wanted and recommend for years and the EPA never made that happen till the DD 2 stroke left the market
good luck

TomC · March 09, 2009, 09:21:29 AM

Sorry if I contradict what anyone else has said, but the new 15ppm (parts per million) sulphur has been carefully formulated with additional additives to NOT cause any lubrication problems. And so far, we haven't seen any in older engines. My Mercedes-Benz with 325,000 miles on it is happy as can be. My 1977 8V-71TATAAC engine is happy as can be. My 1985 Cat 3406B is happy as can be. None of the new engine manufacturers recommend fuel additives-sans when you are going into cold weather-meaning sub freezing to keep the fuel from freezing. I know that Diesel fuel service works since I was in -20 degree weather once and the fuel didn't gel up. Don't try second guessing the giant petroleum companies in the formulas of Diesel fuel. Do you think they want to create problems with their number one selling fuel? Nearly everything runs on Diesel or a close cousin to it (jet fuel is Kerosene with all the water extracted so not to freeze). Besides, our mechanical injectors in the 2 stroker engines are relatively loose compared to the new engines running up to 32,000psi of tip pressure-like the new Detroit DD13, DD15 & DD16. Good Luck, TomC

Sean · March 09, 2009, 09:46:05 AM

Quote from: bigjohnkub on March 09, 2009, 08:33:27 AM
Our Gov't has removed the sulphurs from the fuel (is now less than 5 parts per million) which creates lube problems in older engines. You must put in some type lube.

This is one of those myths and urban legends to which I referred.

First of all, sulfur is not a lubricant. In fact, sulfur is harmful for engines, as it turns into sulfuric acid during combustion. We've discussed this here in the past ad nauseam. For example:
http://www.busconversions.com/bbs/index.php?topic=7033.0

Lubricity problems with ULSD come from loss of aromatic hydrocarbons, which also get removed during the process to remove sulfur. So lubricity additives need to be put in the fuel, to replace those aromatic hydrocarbons. As Tom wrote, those additives are already in the fuel that you buy at the pump -- you can't get the raw stuff without them.

Let me repeat: Detroit Diesel recommends AGAINST any aftermarket additives in the fuel, including ULSD. Read the publication I cited above.

-Sean
http://ourodyssey.blogspot.com

kyle4501 · March 09, 2009, 10:24:36 AM

Thanks Sean.

Along those lines, who are you gonna believe,
- the manufacturer who has a real vested intrest in the performance of the engine & lots of planned & controlled test data to back up their recommendations?
- or advice based on experience with limited, if any, control & minimal data from testing?

It's your money, spend it as you see best.

JohnEd · March 09, 2009, 02:58:03 PM

Along those lines "who are you going to believe, me or your lieing eyes?"

After reading everything I have to date I would suggest the following: Get a tank of B50 or 100. Replace all the filters that running that would cause as often as needed. That should resolve any "build-up" issues in the fuel system. After that I would charge my filters with B100 after change. That should keep all the mechanical injection stuff clean in all the right places. For all the electronic stuff , I think B10 or B20 is a far as you can go but still worth the trip. IMHO, now.

John

Mark Scott · March 10, 2009, 05:36:03 PM

Thanks everyone for their replies. The bus is always stored indoors, gelling is not a problem. I will change filters per the service manual. I have run the tank close to empty and I suspect I have picked up some contaminants in the filter as I noticed a slight decrease in power and acceleration after I filled the tanks. Thanks again. Mark

Sean · March 10, 2009, 06:48:43 PM

Mark,

One of the things I did not mention above about ULSD (but has been discussed in other threads), is that ULSD is a much better solvent than LSD.

One of the consequences of this is that ULSD tends to clean years of accumulated crud out of older fuel systems. Not a problem for the engine, but it will plug up the filters sooner than "normal." Many fleets have confirmed this issue after switching to ULSD.

The general recommendation is to halve the normal filter change interval on both primary and secondary filters for the first 20,000 miles after switching to ULSD.

If your coach was primarily run on LSD previously, this could be an issue for you.

FWIW.

-Sean
http://ourodyssey.blogspot.com

Lin · March 10, 2009, 07:06:46 PM

There was a study that was posted on this site a while back that compared lubricity of untreated diesel using different aftermarket additives. Some, like Marvel, did very poorly. One of the best, as I remember, is was adding vegetable oil. I do not recall the proportion, but it may have been around a quart or so for 50 gallons. That, as mentioned, was with untreated fuel. We are told that the oil companies are adding their own formulas to increase lubricity though. If in doubt, I do not see any harm in adding a little vegetable oil.

One issue often discussed about vegetable oil or biodiesel is that it tends to loosen crud and clog filters for a while. This is not likely to be a problem at a quart per 50 gallons though. It seems that Sean's post would suggest that using ULSD does the same thing, so it would remove one of the nuisance hurtles of using bioD if there is ever a need. Aside from one station in Arizona I filled up at that offered a choice between ULSD and LSD (I this does not provoke and flashbacks), I do not see any others making a distinction. Are we too assume that most small stations are just selling ULSD?

JohnEd · March 10, 2009, 07:21:47 PM

Mark,

What Sean said and mostly what Lin said.

Bio is "converted" or "processed" veg oil. In that process there is a lot of the components of veg(straight vegatable oil, SVO) that is refined out and disposed of. It isn't supposed to be good for a 2 cycle and will kill a fuel rail system. But....there are thousands of guys using it in DD 2 strokes and lots of'em live right here in River City. SVO is a great lubricant but it gels at higher temps and plugs filters even though it isn't a solvent. BioD is a fantastic solvent and a superb lubricant. B10 doesn't seem to do much solventing but it does add all the lubricity that you might want in fuel. B20 and up is said to "clean" the fuel system and B100 is said to really really clean the system and cause filter replacement shortly after a fill. For the cleaning this stuff does to injectors I would gladly put up with a couple filter changes. After the initial house work the filters last as long as they used to so it is a one time consideration.

John