Fuel filter change with ATF in it
 

Someone here posted something that said you shouldn't dump ATF into your new fuel filter. Basically it said that it didn't do anything but soot your prechamber.

Well, on my 85 300SD I changed the filter this weekend. I poured ATF into my new filter and put it on. After idling for a few minutes the slight lope that my car has had since I bought it went away. It idles perfectly smooth now. I think that the ATF helped clean out some injector crud just like the old diesel myth suggests. :D

I take my car to an import shop in town that I trust. The owner was telling me that every time they change a fuel filter on a diesel they fill it up with ATF and having been doing it that way for years with no problems.

I know that a lot of VW diesel guys add either ATF or a little 2-stroke oil on every fill-up

My local MB/Euro mechanic (he's Czech) told one of his techs to fill my new filter with ATF. I ran out of time (he was fixing a vac line) and had to go so I decided to leave the filter for another day. So now I think I'll do it myself this weekend. But how? Is it bolted on (the big bolt in the center top of the canister)?

NO NO NO! ATF in your fuel filter is a very old trick used back in the 50's-60's. Yes since the fuel was so bad back then it had some cleaning properties, but not really a good idea. Will it hurt your engine? No. Is it needed? No. You could also fill up your filter with motor oil or any other viscous petroleum and it will do about the same thing.

I use to work for Cummins and some of the old timers would do it, but it serves no useful purpose. Just fill it with nice clean diesel fuel and use products designed to be run through the IP but not ATF.

All the mechanics I talked to in Germany recommended it. The top W123 mechaninc at the dealer here, recommends it. I did it in my 220D for over 100,000 miles and never replaced anything in the injection system.

The dealer mechanic also discussed the mercedes information about not using the ATF. He pointed out that it seemed to apply to the newer diesels. Not the older W123's, W124, etc. Mercedes did come out with the study in the mid 90's. Prior to that everyone seemed to do it.

I do it.

Dave

PS and I also add a quart of ATF in the tank every once in a while.

Yup.
Piece of cake, just remember to prime the system till you hear the overflow bypass. If your return lines are as skanky as mine were you'll also see fuel oozing through them (fixed as of this evening. No more fuel slicks under the car YEA ME :) )

On another note, the injector return lines to the filter... does that go back to the injectors as it looks like or does it bypass over to the cigar hose for return to tank?

i do it with every filter chand in a shop environment if nothing else for the cars without the primer pump there is less wear on the starter to prime the filter. and on the older models the hand priming isn't needed.

I use ATF or 10W30 to fill fuel filters at work. No real reason, it's just less mess to fill a filter from a 1qt bottle than a 5 gallon fuel jug.

If you want a good fuel additive, pour 8oz of the grey bottle powerservice into the tank when you fill-up or do a round of Diesel Purge every year or so.

File this thread under fear, superstition and ignorance
 

There are two possible routes to take in maintaining your diesel injection system, the way the Mercedes factory shop manual says to do it, or superstition, pagan rites, folklore, and hearsay. For those of you cannot stand to read the factory shop manual this is a cheap, harmless but futile way to play witch doctor. It is kinda fun to do a few times just because you can and it is a good way to empty old containers with a little oil, etc in them. It is just as effective and cheaper than Diesel Purge or Seafoam, etc. Mazola works too and it smells better when it burns, so it may be more pleasing to the gods of compression ignition.

Well ATF in my fuel filter did something to my pump or injectors as my car has a smooth idle now, I don't think its a myth or a wives tale. Its not a placebo effect either. A friend commented that my car sounded smoother and asked me what I did.

I always just pump the fuel primer pump to fill the new spin-on with diesel, then I screw it on, start it up, and go. Easy, no ATF required. :D

My method as well........ now that I replaced that leaky old primer pump. :D

Was doing a search on the topic....this one was all that came up....thought it would be amusing to revive an old thread.

I never have diesel lying around, so using ATF when replacing main fuel filter makes sense for me....as long as it doesn't do any harm. Probably some superstition/folklore stuff going on....it's fun to think you're doing something to help your car (even if there's no basis in fact).

What does anyone else do?

All of the above posts are still valid info. If the cars haven't changed in the last 4 years, why would posts about them? Just sayin'

I have a 2 gallon jug I take down and fill up before I do filter changes. Fill up the filter, then pour the rest in the tank. If I'm feeling lazy, I disconnect the fuel line by the tank to fill up the jug a little...

I would worry about the redish ATF being returned to the tank. While I've never personally had my tank dipped by the authorities, should it ever happen - I don't want anything of a reddish nature in the tank. Red is what they dye farm-grade diesel with. If you are caught on any US road with red dye in your tank, it's a very hefty fine. Akin to tax evasion.