Leaking Injector + Coilpack causing combustion when car is off
Thread Starter
Newbie
Joined: Sep 2024
Posts: 2
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2015 E350
Leaking Injector + Coilpack causing combustion when car is off
Hey everyone, wanted to hear some input. 2015 W212 M276 4matic, upon unlocking car there was a pop noise (like a balloon) then smoke came out from under car and hood - this same issue has been talked about in this thread. Also talked about here.
Running theory is that a leaky injector + faulty coilpack fired when the electronics were woken up upon unlocking. In my case, this has now caused a decent amount of oil to pump out of the dipstick channel after driving. No suction on oil cap while running (no pcv whistle either) and doesn’t leak while stationary.
I just recently had a vacuum pump hose replaced (which was causing oil to pump out of the dipstick) so wondering if its that. Any input on either of these issues would be greatly appreciated!
Will update when everything is taken apart. Thanks!
Running theory is that a leaky injector + faulty coilpack fired when the electronics were woken up upon unlocking. In my case, this has now caused a decent amount of oil to pump out of the dipstick channel after driving. No suction on oil cap while running (no pcv whistle either) and doesn’t leak while stationary.
I just recently had a vacuum pump hose replaced (which was causing oil to pump out of the dipstick) so wondering if its that. Any input on either of these issues would be greatly appreciated!
Will update when everything is taken apart. Thanks!
Last edited by Benchpigeon; Jun 20, 2026 at 10:34 PM.
Out Of Control!!
Joined: Apr 2019
Posts: 12,272
Likes: 6,918
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Hey everyone, wanted to hear some input. 2015 W212 M276 4matic, upon unlocking car there was a pop noise (like a balloon) then smoke came out from under car and hood - this same issue has been talked about in this thread. Also talked about here.
Running theory is that a leaky injector + faulty coilpack fired when the electronics were woken up upon unlocking. In my case, this has now caused a decent amount of oil to pump out of the dipstick channel after driving. No suction on oil cap while running (no pcv whistle either) and doesn’t leak while stationary.
I just recently had a vacuum pump hose replaced (which was causing oil to pump out of the dipstick) so wondering if its that. Any input on either of these issues would be greatly appreciated!
Will update when everything is taken apart. Thanks!
Running theory is that a leaky injector + faulty coilpack fired when the electronics were woken up upon unlocking. In my case, this has now caused a decent amount of oil to pump out of the dipstick channel after driving. No suction on oil cap while running (no pcv whistle either) and doesn’t leak while stationary.
I just recently had a vacuum pump hose replaced (which was causing oil to pump out of the dipstick) so wondering if its that. Any input on either of these issues would be greatly appreciated!
Will update when everything is taken apart. Thanks!
Hopefully not on your watch.
Thread Starter
Newbie
Joined: Sep 2024
Posts: 2
Likes: 0
2015 E350
I saw!!! Lol luckily no explosion after multiple startups, but now have an occasional knock on coldstart. Engine will be taken apart this week…
Out Of Control!!
Joined: Apr 2019
Posts: 12,272
Likes: 6,918
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Is it a rod bearing knock ?
or a low oil pressure startup rattle ?
or a HPFP flat roller knock ?
Hopefully every things go according to plans.
