Guys - is this a fuel filter problem in my 1981 300SD or maybe something else? I was driving fine yesterday then began losing power like it was running out of gas. Barely got it home. Today it started fine but would not rev up - even with full pedal - then it caught and revved fine; however I am afraid to take it out on the road for a test. Looking under the hood I see that the fuel filter is not full and it has a lot of bubbles. I am not sure but it seems like the filter should be completely full without bubbles.

So pls take a look at the pic and let me know if perhaps I just need to replace this diesel fuel filter. While I am at it is there any other fuel filter that should be replaced?

Pic attached. Thanks for the help.

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Changing filters is a good place to start and the easiest way to troubleshoot bad filters. My fuel is yellow. What's in yours? Startron (ask Prof Google where to buy) worked wonders when I had stuff growing in the fuel.

You can consider other things if necessary once you know filters and fuel are good. The pick up screen in the tank can become clogged.

Some air in the clear filter is normal. Mine is nearly fuel filled when running since replacing a couple of leaking hoses. Changing fuel line is maintenance and should be done routinely before problems, rather than after. It is similar to changing radiator hoses before they leak and leave you on the road.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

start from the tank. i was shocked how green my fuel was in the tank and how clear it was at the filter.

Big bubble is standard in the primary filter. All those foamy small bubbles aren't. You might have an air leak.

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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

Thanks for the input. Specifically is the fuel filter supposed to have bubbles? Is it supposed to be completely full of full. Would someone go out and take a look at his fuel filter with the engine running; my pic was with the engine running and I am almost sure it is supposed to be full without bubbles. But someone's visual inspection could prove me wrong.

Thx.

i've always thought that small bubbles means something is obstruction the line.

it looks about as full as mine, those bubble are suspect however.

No. A big bubble is common.

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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

Small foamy bubbles like that is prolly caused by the screen in the tank being plugged. Try some biocide and pull the screen if the tank is low enough. One way to check the screen would be to pull the hose from the screen off the steel line and make sure you have a good stream coming out.

If you have at least 1/2 Tank of Fuel you can swap the Positions of the Fuel Outlet Hose (the Cigar Hose) and the Fuel Inlet Hose where they attach at the Fender Well. That will bypass the fuel Tank Screen and draw Fuel from a higher position in the Fuel Tank (do that for testing only as it also means you would run out of Fuel early).

If the situation improves your Fuel Tank Screen is restricted.

You could also replace the 2 sections of Fuel Inlet Hose with 5/16" ID regular Fuel Hose you can get at the Auto Parts Store as it is also rated for Diesel Fuel.

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84 300D, 82 Volvo 244Gl Diesel

D911-got it.

Thanks.

Pep Boy sold me the plastic see-through filter for $4. However their computer showed a spin on "primary" filter. Is this right? Do I have one on the SD? Anyone know where it is located?

yes you do have a large secondary filter,and your little primary.Becareful not using right filter.Tip: Buy Purolator Filters for your car,they are better than the German ones

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1999 w140, quit voting to old, and to old to fight, a god damned veteran, deutschland deutschland uber alles uber alles in der welt

The primary filter is the clear inline one, the secondary is the spin on one, it has a 24 mm bolt holding it on.

It has a couple of "O" rings on the banjo bolt.

See this post:
Fuel filter O-ring

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83 SD

84 CD

Any similaritys between this thread from a yr and half ago, and the problem today?

81 300SD How to replace fuel filter?

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works