Engine Oil drain plug/bolt
Thread Starter
Junior Member
Joined: Dec 2020
Posts: 17
Likes: 3
2021 GLC43, 2017 C300, 2015 Corvette Z06
Engine Oil drain plug/bolt
Quick question because I've seen so many different answers, and maybe this can save me some time instead of having to hit the part store mid oil change. anyone have a 2021 GLC43 (USA variant) 4matic and know what size is the plug? Asking about the actual thread size, not the socket size, is it M12 or M14
Thread Starter
Junior Member
Joined: Dec 2020
Posts: 17
Likes: 3
2021 GLC43, 2017 C300, 2015 Corvette Z06
Anyway, for those in the future that will inevitably look up the same info: It's a M14 x 1.5 thread. 13mm hex head. 20mm thread length. an example: https://www.ottocarparts.com/shop/pa...pan-08277.html
you will need a 14mm ID crush washer
Last edited by eagl3; Mar 25, 2025 at 10:56 PM.
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Joined: Oct 2019
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From: Colorado
G550
Another consideration is what happens when you sell\trade the vehicle. Even if the repair doesn't show up in the Carfax report, a potential buyer is likely to have the vehicle inspected and the make-shift drain plug repair will be noted. I would be exceptionally wary once this repair was discovered, and not knowing the circumstances having caused it or the consequences (did the stripped plug allow substantial oil loss before being discovered?), I'd likely pass on buying it. The dealer is responsible for damage and is obliged to restore it to its original condition -- don't let him weasel out of it because he expects you to take a loss so he doesn't have to.
