Vacuum leak woes
#26
"Stuck lean" signals a significantly lean condition that cannot be corrected by the ECU. If you didn't see these codes before they could well have been generated by the OBDII self-test cycle that happens probably every few thousand miles. The ECU induces both rich and lean conditions and measures whether minimum or maximum values are exceeded. My guess is that you are therefore running not just lean but very lean to be "stuck." (I've been "stuck rich" before.) Therefore there may well be more than just a slight air leak going on. Problematic as the primary O2 sensors are with this this engine, replacing them is a no-brainer IMO.
Last edited by bhamg; 06-08-2017 at 04:48 PM.
#27
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SO after what feels like an eternity of having my car off road and not used (I was working on my other cars and needed to focus on those etc) i finally got the car working as normal again today.
I bought a used intake manifold from Germany which supposedly came out from a 2012 C63. I already had a fresh set of gaskets n bolts waiting (one of which snapped....second time it's happened to me!) so it was fairly straightforward to fit to the motor. The car runs....as it should, so I guess that was the solution to my issue.
Still doesn't make sense to me if the old manifold was deemed to be true from the engineering shop and it passed a smoke test, but there you go....
If I have time next week, I'll attempt to fit my 82mm throttle bodies in and update the TB thread if I manage to make any progress.
I bought a used intake manifold from Germany which supposedly came out from a 2012 C63. I already had a fresh set of gaskets n bolts waiting (one of which snapped....second time it's happened to me!) so it was fairly straightforward to fit to the motor. The car runs....as it should, so I guess that was the solution to my issue.
Still doesn't make sense to me if the old manifold was deemed to be true from the engineering shop and it passed a smoke test, but there you go....
If I have time next week, I'll attempt to fit my 82mm throttle bodies in and update the TB thread if I manage to make any progress.
#30
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2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Great news
#31
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#32
Yup, but good to hear you've solved the problem. My guess is this motor consumes maybe 500CFM of air @ 5kRPM so it's difficult to imagine hairline cracks making any difference at all. GL with the TB's.
#33
SO after what feels like an eternity of having my car off road and not used (I was working on my other cars and needed to focus on those etc) i finally got the car working as normal again today.
I bought a used intake manifold from Germany which supposedly came out from a 2012 C63. I already had a fresh set of gaskets n bolts waiting (one of which snapped....second time it's happened to me!) so it was fairly straightforward to fit to the motor. The car runs....as it should, so I guess that was the solution to my issue.
Still doesn't make sense to me if the old manifold was deemed to be true from the engineering shop and it passed a smoke test, but there you go....
If I have time next week, I'll attempt to fit my 82mm throttle bodies in and update the TB thread if I manage to make any progress.
I bought a used intake manifold from Germany which supposedly came out from a 2012 C63. I already had a fresh set of gaskets n bolts waiting (one of which snapped....second time it's happened to me!) so it was fairly straightforward to fit to the motor. The car runs....as it should, so I guess that was the solution to my issue.
Still doesn't make sense to me if the old manifold was deemed to be true from the engineering shop and it passed a smoke test, but there you go....
If I have time next week, I'll attempt to fit my 82mm throttle bodies in and update the TB thread if I manage to make any progress.
#34
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I tell you what though, the additional bodge-sealing on my airboxes (I'm guessing particularly at the back behind the MAFs) seems to have helped to make the drivability a lot smoother and responsive at light throttle inputs
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