For a 85 300sd,how many miles do they recommend before you are suppost to change fuel filters? thanks

On the original dealer regemin it was probably a yearly/bi-yearly replacement part, so I'd guess every 15-20k? Depends how good the fuel is in your area I suppose, I went about 22-23k on one before I noticed some power loss from sludge in it.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Funny thing about fuel filters. Some of them last for years........some last for months.......depending on the fuel you buy.

A recommendation from M/B is basically meaningless. I'll probably change these after three years on principle........or........if the vehicle performance deteriorates..........basically on condition.

You'll know when to change them.........if you have any sense of performance of the vehicle.

Dave....if your living in the snow-belt of the US or Canada I think its a good policy to change your fuel filters on any diesel vehicle before the winter season. Cold/gelling diesel fuel passes through a clean filter better than even a slightly dirty one. And a fuel filter is cheaper than a tow in the middle of winter.

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FRED

Daily Driver: 98 E300TD 199K
Hobby Car: 69 Austin Mini
Past Diesels: 84 300SD, 312K
87 300SDL, 251K
94 Chev. K-1500 6.5Ltr.TD, 373K

I just carry spares and replace them when I notice a lose of power. If you've ever had a clogged filter, you will know the symptoms. A few weeks ago, I suddenly lost power while driving through Iowa. My 300D would slow down to 55 or 65 on hills that I normally drive at 80 with no problem. With the correct wrench, you can change both filters in about 5 minutes.

It is definately an easy change. I did have to remove the bolt holding a bracket in place to make room to get the filter out. I carry a bottle of SeaFoam injector cleaner in the trunk. Fill the filter with SeaFoam before you install it. That will do 2 things for you.
1- Reduce the amount of time needed to prime the line. (Less air->less priming needed.)
2- Clean your injectors.

If you run grease or biodiesel you could keep a quart of cheap transmission fluid in the trunk. It is mostly kerosene anyway. Since the filters will clog more frequently after you switch to biodiesel (it cleans out the dino junk from the bottom of the fuel tank) you will be changing filters well before you need to run another bottle of cleaner through the injectors.

-Jim

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1995 S350D, Green with black leather interior.
Bought January 2008 w/ 233,xxx miles.
I did 22,000 miles during the first year of ownership.

I do mine every fall before I put the car into storage.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Fuel filter mileage:

30,000 miles on really clean diesel
10,000 miles on cruddy diesel
25 miles on Dastardly Dan's Discount Diesel

Does that help?

Seriously though, I do mine when I feel like it, roughly once a year. They are cheap, and what I fear more than clogging, is one of them breaking internally and dumping crapola into the injection pump.

I just changed them the other day, after having gone 19,000 miles on both the primary and the secondary. The car ran just fine, but I changed them cause it was a nice day, I was under the hood anyway, and am taking a long trip soon, so want to hassle with as little as possible on the road.

Also, I'd recommend doing a Diesel Purge right before changing your filters, since you need to change filters after a purge anyway, so might as well do it right before you were going to change them anyway.

Also, clear fuel filters are much handier than the opaque white ones. Dieselgiant.com has the clear ones for a good price, though you can get them lots of places.

peace,
sam

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"That f***in' biodiesel is makin' me hungry."

1982 300TD Astral Silver w/ 250k (BIO BNZ)
2001 Aprilia SR50 Corsa Red w/ 5.5k (>100 MPG)

Phil has them, I did the math, and at least for shipping to my area, Phil is cheaper than dieselgiant, and you support this site when you order them from him.

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'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.

Changed mine today-You can tell when they plug.Had 6000 miles on them,but do not know how many miles on filters before i got the car.I am thinking my filters might not have been bad.The bleed bolt on top of the filter was loose. I think I was sucking air.