Wow, 4 years? You must get good, clean fuel where you are. I usually change the fuel filter every other oil change in my Diesels.

One thing I find surprising on these old Benz cars is that there is no water separator device. I would hate to see what happens if a large amount of water gets into the fuel system and is not caught and enters the IP. That can't be fun. I'll have to look at a water separator in the future.

Be glad the Benz filters are less than $10. The one for my 7.3 IDI usually goes for about $30 but at least it has a water drain in it.

__________________
1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge

Well, you could understand my experience as evidence that the filters have an 'auto-water drain' once it accumulates enough water.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

X2
I am with you on this Andrew.
The one liners are nothing more than infraction bait.
The practice of doing the secondary when you do your valves is a good one. Yes you do have the hood up & so its a perfect time, along with many other things like lube of throttle linkages.
At the same time I can see Kerry's point that early replacement does not achieve much. The thought of a fuel filter blockage on a freeway in the rain when you are in a suit on your way to an important meeting is enough reason for me to change it once a year when the hood is up & the valves are being done. If you have good fuel, maybe then when ever you change your trans oil & filter.
The jeep has a Raycor filter with a water warning light & drain. Much better.

__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

Have you drained the water out of your fuel tank lately? MB's have a water separator, its called the fuel tank & if not emptied now & again the water fills up enough & finds its way to the filter.

__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

I am going to assume that you meant to say "Sir" instead of "dude."
I wanted to hear the logic behind your recommendation. There is no obvious connection between a valve adjustment and a fuel filter replacement.

whunter described his personal practice without further comment. It was you who recommended the practice as a good idea. It's one thing to say "I replace my fuel filters every third blue moon." It's a bit different to say "It's a good idea to replace your fuel filter every third blue moon."


Have you ever opened an old filter and personally observed the level of contamination? Fact is, it is possible to have an incredibly clean filter after years in service. And it's possible to completely clog a new filter with just one bad fill-up. The smart operator is less concerned about periodic replacement and more concerned about have a spare on board if needed.

Fortunately, that deficiency is easy to rectify. And well worth the effort and expense, neither of which are significant.

I installed a Stanadyne FM-10 several years ago; works well with no apparent negative side effects.

+1

I have gone one step beyond keeping a replacement fuel filter in the car, I have installed a vacuum gauge to monitor filter condition (normally a pressure gauge is required in a Mercedes but my Mercedes is not normal so I use a vacuum gauge ). I can see when the filter begins to clog by monitoring gauge readings and I only change it when the gauge tells me to.

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

More details, please?

Good system. However, it wont give a warning prior to the filter springing a leak. I have a system like that on my Wanderlodge and it is useful.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Trolls, here?

Surely you jest.

__________________
83 SD

84 CD

As a filter clogs, the pressure or suction required to move fuel through it increases. Tee-ing in a pressure or vacuum gauge between the lift pump and the filter allows you to measure fuel pressure or vacuum.

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Not prior but immediately after the filter spring a leak, the vacuum or pressure reading will drop.

In the absence of oxygen, it's unlikely your filter rusted from the inside out due to water. If the filter ruptured from the water inside freezing, that is a significant amount of water and I can't believe some sort of IP damage has not occurred. If it was water freezing causing the rupture, you should see signs of bulging. Maybe (in your situation) it's more likely that the plating was scraped off/ damaged and the filter rusted from the outside in? Or maybe a hose was rubbing against the bottom of the filter? I've seen that happen before.

Maybe the inline IP's are more tolerant to water than the VE IP's, thus the reason Mercedes did not incorporate a water trap, a filter drain, or a water in fuel warning system? The 617.9xx tanks gravity feed the lift pump. I believe the lowest point in the tank is the fuel strainer so any water in the tank will make it's way to the fuel filters. Not good IMO.

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Since fuel filters are inexpensive, I change them once a year whether they need it or not. It's a good excuse to handle the fuel lines and check for rotting hoses and other problems before they leave you on the side of the road.

Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Thanks!

I have a 06 Duramax and just purchased a 178K 98 E300D. I was having a discussion with a Ford Powerstroke owner and he said he drains his fuel filter manually every couple of weeks and gets at least a cup of water out each time. This is in WV. I just recently moved from CO and never had a water problem. The Chevy doesn't have a drain but a water sensor that will signal water in the system. Never has triggered yet.

So, since the Benz doesn't have a drain, or a water sensor it would seem to me that you should either remove the filter and dump it out periodically, or replace it from fear of water build up.

I suspect the manufacturer has recognized these issues but must not consider them of major consequence since there is nothing mentioned of maintenance intervals for water prevention.

Anyone seen factory info on water issues?