Hello, all.

My 1987 300D has been quite sluggish lately, so I decided to change the fuel filters and see whether that will take care of the problem. I was able to change the secondary filter, the canister one. However, I cannot locate the smaller primary filter. I've only been able to find pictures and videos showing the location on other model years, but not for the '87. I was wondering whether any of you could post a picture that shows the location, or just give a description of where I should be able to find it. Thank you in advance. :-)

I take it you know what it looks like? That would be the first thing. Look for the two fuel lines coming from the driver's side fire wall. One of them will go straight to the primary filter. Should be on the driver's side and visible without moving anything around.

Welcome to the forum!

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 154k miles
06 E320 CDI "Rutherford", Black on Tan, 172k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 142k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

That's what I've read, but I still don't see it. Also, yes, I know what it looks like because I've already purchased it and I've seen it in pics on here. Should it be visible in any of these pictures? Also, upon looking for that, I noticed a hose that appears to be severed. It's the one circled in red. Do you recognize that?

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it's entirely possible the PO removed the clear inline filter...why I don't know...unless it clogged and they didn't have a spare on hand...

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1987 300TDT
1981 VW MKI Caddy 1.6 diesel, waiting on engine swap
1983 D-50 Power Ram 4x4 "Mitsubishi" 2.3 turbo diesel
assorted gas powered crap and motorcycles

RIP: 1984 300TDT, 1982 300TDT, 1984 190D 2.2, 1992 300D 2.5, 1987 300TDT, 1982 Maxima LD28, 1983 Maxima LD28, Isuzu C223 P'ups X3, 1983 Holiday Rambler 6.2 Banks turbo diesel, 1984 Winnebago LeSharo 2.1 TD, 1985 Allegro 6.5

circled in red is a vaccum hose i believe...mine is dead in a parking lot so I can't check mine real quick

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1987 300TDT
1981 VW MKI Caddy 1.6 diesel, waiting on engine swap
1983 D-50 Power Ram 4x4 "Mitsubishi" 2.3 turbo diesel
assorted gas powered crap and motorcycles

RIP: 1984 300TDT, 1982 300TDT, 1984 190D 2.2, 1992 300D 2.5, 1987 300TDT, 1982 Maxima LD28, 1983 Maxima LD28, Isuzu C223 P'ups X3, 1983 Holiday Rambler 6.2 Banks turbo diesel, 1984 Winnebago LeSharo 2.1 TD, 1985 Allegro 6.5

I think it's clear/yellow-y and under the inlet manifold on the 300D. Tricky to tell from the pic but that looks like a vacuum hose connector- the vacuum line looks like it's unplugged and bunched in with the other lines below?

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1993 320TE M104
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past:

1983 230E W123 M102
1994 E300D S124 OM606 (x2)
1967 250SE W108 M129
1972 280se 3.5 W108 M116
1980 280SE W116 M110
1980 350SE W116 M116
1992 300E W124 M103
1994 E280 W124 M104
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"music and women I cannot but give way to, whatever my business" -Pepys

Have you identified the two fuel lines coming from the firewall? They're on the right of the first two pics. Follow both those lines. One of them SHOULD go to the primary filter. If neither does, then it's been removed....really odd. I don't see it in any of the pics.

__________________
14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 154k miles
06 E320 CDI "Rutherford", Black on Tan, 172k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 142k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

If my memory serves me right .... your power will be restored if you reconnect the vacuum hose circled in red. I believe that is the hose that ultimately provides "pressure" to move the fuel rack forward and thus inject more fuel into the cylinder when the turbo kicks in. More fuel equals more power. It's obvious to me that someone removed the "clear strainer fuel filter", so I suggest you just "cut one in" into the line coming from the tank .... it's purpose is to catch or remove the larger chunks of crud and rust from the tank .... those larger pieces if not filtered out could clog things up and create problems. Good Luck.

Thank you all for the responses so far. The first thing that I want to do is reconnect that vacuum hose. Is there anything special that I'll need for that?

Nothing special needed. Just push the two pieces together. If the hose is hard and the connection is loose you may need to get a new "fresh" section of rubber vacuum hose maybe a little longer so the two parts don't pull apart when the engine moves around at start up or turn off.

Look at the picture arrow.


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