SL-Class (R129) 1990-2002: SL 280, SL 300, SL 320, SL 500, SL 600, SL 60 AMG

SL/R129: 500sl rough idle, broken pipe??

Old Jan 9, 2020 | 08:49 AM
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500sl r129
500sl rough idle, broken pipe??

Hello guys,

First post on mbworld 🤟. Hope you merc fans have had a great festive season 😊.
i recently got a 500sl and bless her she’s been somewhat neglected. I’ve been daily driving for a while now and have done the caps and rotors, cam pos sensor and the fan tensioner and belt.
im going to do the fuel distributor, pump and filter soon.
the idle is rough on the car. Kind of like a rotating sound and the car shakes a fair bit. It’s better when it’s in gear but still shakes slightly.
today I found a broken line at the back of the engine and was wondering what it is and where the rest of the pipe goes and if it could be contributing to the rough idle?



Please see pictures 😊 any help would be great. Cheers guys.
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Old Jan 11, 2020 | 01:18 AM
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500sl r129
  1. Anyone?? 🤟
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Old Jan 12, 2020 | 03:42 AM
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R129 SL55 AMG & W208 CLK55 AMG
I have the same issue, and you solution could help me as well.
Personally? I would look at the harmonic balancer if your rough idle is only in nuetral.
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Old Jan 14, 2020 | 07:47 PM
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From: Atlanta, unfortunately
'09 S600, (2) R129 300SLs, '03 SL500, '03 SL55
There is a vacuum line from the engine to the modulator on the side of the transmission. I'll guess that's the hose you show.
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Old Jan 15, 2020 | 12:57 PM
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SL600
Hallo,

this is a vacuum line between the intake and a distributor under the cover passenger side. And yes, something like this leads to a rough engine, too.

Regards

Andreas
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