Recommended diesel fuel additives? - Page 3 - PeachParts Mercedes-Benz Forum

aklim · #31 10-10-2006, 10:24 PM

Quote:

Originally Posted by H-townbenzoboy

Mercedes-Benz doesn't recommend additives, but it's a good idea to use a water sequestering additive in the winter,

Red bottle of HEET works for that reason.

aklim · #32 10-10-2006, 10:26 PM

Quote:

Originally Posted by gsxr

For a 1-time strong cleaning get Lubra-Moly Diesel Purge (this doesn't go in the tank, though).

I thought about doing that but decided against it. Pulled injectors after 100K. 1 had bad spray pattern and low pop-off pressure. They disassembled it and cleaned it then reassembled it and it was fine. Cost me about $70 plus the seats for the injectors. I don't think DP will be able to do that.

Rudolphrocks · #33 10-11-2006, 08:50 AM

Quote:

Originally Posted by Joel1972

I have looked on Power Service's Web site and looked for a place to buy it, but to no avail. Are there any major auto parts places that you know of where I could buy it?

Thanks

NAPA, or any place that serves a few fleets, we keep 2 cases each of standard PS, PS diesel 911, and Diesel kleen in stock at all times

gsxr · #34 10-11-2006, 11:02 AM

Quote:

Originally Posted by aklim

I thought about doing that but decided against it. Pulled injectors after 100K. 1 had bad spray pattern and low pop-off pressure. They disassembled it and cleaned it then reassembled it and it was fine. Cost me about $70 plus the seats for the injectors. I don't think DP will be able to do that.

You'd be surprised... DP is potent stuff. If it doesn't work, then it's time to pull all the injectors, have them pop tested, cleaned, and pressure-matched.

aklim · #35 10-11-2006, 11:26 AM

Quote:

Originally Posted by gsxr

You'd be surprised... DP is potent stuff. If it doesn't work, then it's time to pull all the injectors, have them pop tested, cleaned, and pressure-matched.

I usually have my gas injectors cleaned every 100K. Probably do it for my diesel injectors too. Problem is that injectors are internal and you cannot see what is happenning. Maybe cleaning and checking them ever so often is a good idea

DieselAddict · #36 10-11-2006, 01:17 PM

Quote:

Originally Posted by Jeremy5848

That is an interesting comment. How sensitive are diesel engines to fuel quality, compared to gasoline engines? Certainly the octane level of RUG has greatly decreased (not to mention all of the anti-smog crap they blend in here in California). I can well imagine a compression-ignition engine being unhappy with fuel that wouldn't explode at the right time or burn completely. Was diesel fuel better (a) in the 1980s or (b) in Europe?

Diesel was both better in the 80's and it's always been better in Europe. The main difference is cetane and lubricity. In the old days diesel had higher cetane and more lubricity because it wasn't hydrotreated to remove sulphur. Higher cetane is good because it reduces emissions and stress on engines due to lower peak pressures (which also reduces noise). And lubricity is good because it reduces wear on moving parts in the fuel system like injector nozzles. As far as additives are concerned, I can clearly tell a difference in the level of noise and sometimes exhaust smell too when I do use additives.

#37 10-11-2006, 03:38 PM

Any other DIY ways to clean injectors? Have done the Diesel purge with Moly. Noticeable difference, but the poor gal still nails on a cold start.

DieselAddict · #38 10-11-2006, 04:15 PM

Quote:

Originally Posted by mrhills0146

Any other DIY ways to clean injectors? Have done the Diesel purge with Moly. Noticeable difference, but the poor gal still nails on a cold start.

Sometimes you just have to pull the injectors out and test their spray pattern.

aklim · #39 10-11-2006, 11:21 PM

Quote:

Originally Posted by mrhills0146

Any other DIY ways to clean injectors? Have done the Diesel purge with Moly. Noticeable difference, but the poor gal still nails on a cold start.

I think you are going to have to pull the injectors and have it professionally checked at this time.

greasybenz · #40 10-11-2006, 11:27 PM

Quote:

Originally Posted by mrhills0146

Noticeable difference, but the poor gal still nails on a cold start.

a valve adjustment and a synthetic oil might fix that.

gsxr · #41 10-12-2006, 02:32 PM

And frequent Italian tuneups. It took a couple of years but my old 617 finally got nice & quiet even on cold starts, without any injector removal/repair.

aklim · #42 10-12-2006, 05:04 PM

Quote:

Originally Posted by gsxr

And frequent Italian tuneups. It took a couple of years but my old 617 finally got nice & quiet even on cold starts, without any injector removal/repair.

Why did you wait that long instead of checking the injectors?

gsxr · #43 10-12-2006, 05:08 PM

Actually I did. They had a good pattern and pressures were in spec and fairly close together. Bottom line, if you've got a carbon problem in the prechambers or cylinder, it can take time to burn it out, unless you feel like pulling the prechambers & manually cleaning them (not fun). My 603 spends a little time at the dragstrip, so this has never been a problem on that engine, heh-heh.

aklim · #44 10-12-2006, 05:11 PM

Quote:

Originally Posted by gsxr

Actually I did. They had a good pattern and pressures were in spec and fairly close together. Bottom line, if you've got a carbon problem in the prechambers or cylinder, it can take time to burn it out, unless you feel like pulling the prechambers & manually cleaning them (not fun). My 603 spends a little time at the dragstrip, so this has never been a problem on that engine, heh-heh.

Mine were fine after 55K when we took the head off because of a broken GP. I suppose I might take them out in 100K when I am doing the injectors again. I kinda schedule injector testing and cleaning as a PM item. Also I do the ITU a few times a day just to make sure nothing accumulates.

Jeremy5848 · #45 10-24-2006, 01:45 AM

I've always believed that fuel additives (anything with "miracle" in the name, as Click and Clack say) were just so much snake oil. Lately, I am starting to change my mind because my mileage has improved since I started using Red Line 85Plus.

I've always been sensitive to the mileage numbers of others because my "California version" 300D gets poorer mileage than the "federal" versions (18-20 around town and 24 on the road) and running biodiesel worsens those numbers around town. (I usually run petrodiesel on the road because it's so hard to find biodiesel in the West.)

Last March, my indy recommended Red Line 85Plus, both for filling the new secondary fuel filter and for putting in the fuel tank. In September, I finally started using a couple of ounces with every fillup and my mileage does seem to have improved. In the past month I've averaged 21 MPG compared to about 18 MPG previously.

We all know about the "psychosomatic" effects of making a change of this type. Unconsciously, we start to drive more carefully and end up getting the results we want to get. (Hey, whatever it takes!) But I swear, I'm not driving with any lighter a foot than before (even though I should). I suspect that the cetane boost that the additive gives to the biodiesel is responsible for the improvement.

I'll continue to monitor this and am anxiously awaiting our annual Christmas trip to Utah, which will be my next chance to put significant miles on the car in a short time. Except for the first leg (Santa Rosa--Reno), I'll run petrodiesel all the way and will continue to add 85Plus. Results will be posted as I get them.

Jeremy