Mystery Goop
Thread Starter
Member
Joined: Mar 2025
Posts: 90
Likes: 44
From: Bloomington, IN
2010 GLK350, 2021 Taco, 2019 Lexus GX460, 2009 BMW 335d, BMW 328xi
Mystery Goop
Good morning all,
It’s been a while since I’ve posted! My GLK has been working very well, with no major issues. I had to replace the blower motor controller/resistor, which was fast, cheap and easy.
On to the mystery goop, the main topic of this post.
One time this past winter I saw a small trail of sludgy looking black goop leading into the GLK garage side. Put the car on the lift and didn’t see any source. I checked all fluid levels, and all were fine. The color and consistency of the goop led me to believe it was not a typical fluid, but more likely an accumulation of road grime mixed with some…something…maybe ectoplasm from Ghostbusters. It happened again a couple times between then and now, with no obvious source of the goop. I replaced the rear rotors and pads yesterday along with engine oil and serpentine belt as part of regular maintenance. I decided to spend a bit more time poking around the front end, and I found the culprit. It was (still is) the passenger side control arm bushing. These are fluid-filled on these cards.
It should be a pretty straightforward job. Any recommendations on manufacturer? I’ll likely go with FCP Euro or AZAutohaus as a source.
Thanks,
It’s been a while since I’ve posted! My GLK has been working very well, with no major issues. I had to replace the blower motor controller/resistor, which was fast, cheap and easy.
On to the mystery goop, the main topic of this post.
One time this past winter I saw a small trail of sludgy looking black goop leading into the GLK garage side. Put the car on the lift and didn’t see any source. I checked all fluid levels, and all were fine. The color and consistency of the goop led me to believe it was not a typical fluid, but more likely an accumulation of road grime mixed with some…something…maybe ectoplasm from Ghostbusters. It happened again a couple times between then and now, with no obvious source of the goop. I replaced the rear rotors and pads yesterday along with engine oil and serpentine belt as part of regular maintenance. I decided to spend a bit more time poking around the front end, and I found the culprit. It was (still is) the passenger side control arm bushing. These are fluid-filled on these cards.
It should be a pretty straightforward job. Any recommendations on manufacturer? I’ll likely go with FCP Euro or AZAutohaus as a source.
Thanks,
Last edited by Sgt Pepper; Jun 21, 2026 at 07:43 AM.
Senior Member
Joined: Feb 2020
Posts: 499
Likes: 154
From: Lac Ste. Marie, Quebec
2006 Alfa Romeo Brera, 2010 GLK350, 2018 BMW 640i GT, 1997 Subaru SVX, 2012 Moto Guzzi Norge GT8V
Dorman are total junk. First one lasted 2 months and the replacement lasted another 16 months. Lemforder surprisingly only lasted 18 months. I'm trying Delphi this time around.
The original parts lasted 14+ years.The quality of replacement parts has really gone down the tubes.
The original parts lasted 14+ years.The quality of replacement parts has really gone down the tubes.
Last edited by Silver Shadow; Jun 21, 2026 at 08:37 AM.
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Joined: Sep 2013
Posts: 2,388
Likes: 708
2021 GLB250 FWD, 2023 GLA250 FWD, 2013 C250, 2015 GLK350, 2005 ML350SE, 2003 E320
Dorman are total junk. First one lasted 2 months and the replacement lasted another 16 months. Lemforder surprisingly only lasted 18 months. I'm trying Delphi this time around.
The original parts lasted 14+ years.The quality of replacement parts has really gone down the tubes.
The original parts lasted 14+ years.The quality of replacement parts has really gone down the tubes.
MBWorld Fanatic!
Joined: Jun 2021
Posts: 1,971
Likes: 534
From: New Hampsha
'17 GLS450, '14 GLK250, Grandpa's Roadster
I put Lemforders on two years ago. So far, so good... (Knock wood!)
[Edit] Oh, by the way, if you have AWD, the Lemforders are a Chinese puzzle to fit in. FCP sells another manufacturer (Febi?) that has a different shaped ball joint that reportedly goes in easier.
[Edit] Oh, by the way, if you have AWD, the Lemforders are a Chinese puzzle to fit in. FCP sells another manufacturer (Febi?) that has a different shaped ball joint that reportedly goes in easier.
Last edited by John CC; Jun 21, 2026 at 03:08 PM.
MBWorld Fanatic!
Joined: Jun 2021
Posts: 1,971
Likes: 534
From: New Hampsha
'17 GLS450, '14 GLK250, Grandpa's Roadster
FCP Euro lists Lemforder as the original equipment manufacturer, but I can attest to the fact that the ones I tool out and the new Lemforders I put in were a subtly different shape on the ball end.
Member
Joined: Mar 2017
Posts: 184
Likes: 45
From: Toronto, Canada
2010 GLK350 4matic
that was the worst part, I already re booted the cx axle 6 months back and dreaded tearing the boots, I wrapped the boots and the top edge of the ball joint and greased them up so they could slide against the boot easier.
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Thread Starter
Member
Joined: Mar 2025
Posts: 90
Likes: 44
From: Bloomington, IN
2010 GLK350, 2021 Taco, 2019 Lexus GX460, 2009 BMW 335d, BMW 328xi
I appreciate all the Feedback. I figured the Lemforder arms would be as good as the originals, but maybe that is not the case. When they failed, did they loose their goop or did they simply develop play? Are all the aftermarket arms fluid-filled?
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Thread Starter
Member
Joined: Mar 2025
Posts: 90
Likes: 44
From: Bloomington, IN
2010 GLK350, 2021 Taco, 2019 Lexus GX460, 2009 BMW 335d, BMW 328xi
I appreciate all the Feedback. I figured the Lemforder arms would be as good as the originals, but maybe that is not the case. When they failed, did they loose their goop or did they simply develop play? Are all the aftermarket arms fluid-filled?
Last edited by Sgt Pepper; Jun 22, 2026 at 09:10 AM.
Senior Member
Joined: Feb 2020
Posts: 499
Likes: 154
From: Lac Ste. Marie, Quebec
2006 Alfa Romeo Brera, 2010 GLK350, 2018 BMW 640i GT, 1997 Subaru SVX, 2012 Moto Guzzi Norge GT8V
They developed a lot of play and got very noisy. To be honest though, the roads around here are extremely rough and full of potholes. It is definitely a torture test for all suspension components.
