Help finding the correct bolt part#
Thread Starter
Senior Member
Joined: Mar 2022
Posts: 342
Likes: 112
2015 C400 4MATIC Palladium Silver Metallic
Help finding the correct bolt part#
Hello, I've searched all around, but there are too many possibilities.
I'm looking for the bolts that connect the tops of the downpipes to the "intermediate pipe" (small flanged pipe on the turbo outlet) on my 2015 C400.
It should be the same for all M276.8 engine cars.
I found the clamps for the bottom of the downpipes, and the seals tor the top, but would like to replace the top bolts, they're quite crusty.
I'm looking for the bolts that connect the tops of the downpipes to the "intermediate pipe" (small flanged pipe on the turbo outlet) on my 2015 C400.
It should be the same for all M276.8 engine cars.
I found the clamps for the bottom of the downpipes, and the seals tor the top, but would like to replace the top bolts, they're quite crusty.
Super Member
Joined: Jun 2025
Posts: 794
Likes: 254
From: USA
For your M276.8 downpipe-to-intermediate-pipe connection, you’ll need M8 x 25mm flange bolts (usually with a 13mm head). They’re often stretch bolts, so one-time-use. MB part # N91088401 (or equivalent aftermarket). Hit up the dealer or FCP Euro for OEM. Since they’re crusty, soak ’em in penetrant first snapped exhaust bolts are a nightmare. Swap the gasket too while you’re in there.
Thread Starter
Senior Member
Joined: Mar 2022
Posts: 342
Likes: 112
2015 C400 4MATIC Palladium Silver Metallic
For your M276.8 downpipe-to-intermediate-pipe connection, you’ll need M8 x 25mm flange bolts (usually with a 13mm head). They’re often stretch bolts, so one-time-use. MB part # N91088401 (or equivalent aftermarket). Hit up the dealer or FCP Euro for OEM. Since they’re crusty, soak ’em in penetrant first snapped exhaust bolts are a nightmare. Swap the gasket too while you’re in there.
Super Member
Joined: Jun 2025
Posts: 794
Likes: 254
From: USA
The bolts you need are M8 x 25mm flanged hex head bolts (Mercedes part N000000007501). They should have a 13mm head and be heat-treated since they’re near the turbo. If yours are crusty, consider replacing them with new OEM bolts or high-temp aftermarket equivalents (like ARP stainless). Double-check with a dealer or parts system like EPC to confirm fitment for your exact model, but these should be correct for the M276 turbo flange.
