Air Filter change now rough idle
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2012 Mercedes-Benz GLK350
Air Filter change now rough idle
I recently changed the air filter on my 2012 GLK350, and now it's running terribly. Rough idle, no power, etc. I have codes but no reader. I've read this can be due to the cover not seating properly, which makes sense as it ran just fine before I changed the filters out. Any tips or other things I can be looking for?
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2012 Mercedes-Benz GLK350
I'll do that when I get home tonight. This feels the most plausible as I didn't do anything but take the cover off, change the filters, then put it back on (unless I broke something, which seems highly unlikely).
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Just FYI, you are supposed to run "adaptations" after changing the filter, to reset the learned parameters from the old filter. I didn't do it, and things worked out fine, but, if you're supposed to, there must be a reason.
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Are you serious? Air filters need to be "registered" like new batteries? What if you only remove the filter, vacuum out the crud and put it back in? The engine can't figure out air mass?
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2012 Mercedes-Benz GLK350
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2014 GLK350 base model (active) ; 2001 E320 base (retired); 2001 Wrangler soft-top
It entails nothing.
I've changed the air filter three times (you know, put a new one in), and have NEVER done an adaptation or reprogramming or what-not. Simply pop the top, remove old filter, insert new filter properly, snug cover. Done.
It was also mentioned having to "adapt" (or program) when swapping to a new battery. We just recently swapped in a new battery (the big one under the hood) ... zero reprogramming required ... also replaced the Aux battery in the back trunk two years ago ... no programming. This is for our 2014 GLK 350 Base.
I have read where folks got the wrong filter and it caused issues. That will happen with ANY vehicle. Heck, the 2001 Jeep will complain if the air filter is not a proper fit.
I've changed the air filter three times (you know, put a new one in), and have NEVER done an adaptation or reprogramming or what-not. Simply pop the top, remove old filter, insert new filter properly, snug cover. Done.
It was also mentioned having to "adapt" (or program) when swapping to a new battery. We just recently swapped in a new battery (the big one under the hood) ... zero reprogramming required ... also replaced the Aux battery in the back trunk two years ago ... no programming. This is for our 2014 GLK 350 Base.
I have read where folks got the wrong filter and it caused issues. That will happen with ANY vehicle. Heck, the 2001 Jeep will complain if the air filter is not a proper fit.
Last edited by calder-cay; Sep 24, 2025 at 09:26 PM.
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Thread Starter
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Joined: Aug 2022
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2012 Mercedes-Benz GLK350
It entails nothing.
I've changed the air filter three times (you know, put a new one in), and have NEVER done an adaptation or reprogramming or what-not. Simply pop the top, remove old filter, insert new filter properly, snug cover. Done.
It was also mentioned having to "adapt" (or program) when swapping to a new battery. We just recently swapped in a new battery (the big one under the hood) ... zero reprogramming required ... also replaced the Aux battery in the back trunk two years ago ... no programming. This is for our 2014 GLK 350 Base.
I have read where folks got the wrong filter and it caused issues. That will happen with ANY vehicle. Heck, the 2001 Jeep will complain if the air filter is not a proper fit.
I've changed the air filter three times (you know, put a new one in), and have NEVER done an adaptation or reprogramming or what-not. Simply pop the top, remove old filter, insert new filter properly, snug cover. Done.
It was also mentioned having to "adapt" (or program) when swapping to a new battery. We just recently swapped in a new battery (the big one under the hood) ... zero reprogramming required ... also replaced the Aux battery in the back trunk two years ago ... no programming. This is for our 2014 GLK 350 Base.
I have read where folks got the wrong filter and it caused issues. That will happen with ANY vehicle. Heck, the 2001 Jeep will complain if the air filter is not a proper fit.
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2012 Mercedes-Benz GLK350
I put the old filters in and it's still running like garbage. It feels like the air box isn't hooked up, but everything looks and feels right under the hood. I've checked the MAF coupling, the intake hoses, and whatever that air pump is that hooks up in front; all appears well.
Did I break something? How is that even possible? I wasn't manhandling it, but even if I were it shouldn't break this easily. Air filters are easy things to do and there's almost nothing to screw up, right? What an I missing?
Did I break something? How is that even possible? I wasn't manhandling it, but even if I were it shouldn't break this easily. Air filters are easy things to do and there's almost nothing to screw up, right? What an I missing?
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2012 Mercedes-Benz GLK350
The old filters I took out are the same, and it's just an air filter. It's not like I put in cheap sparks or eBay rotors; even a bad air filter is usually pretty decent (and the good ones are often restrictive, so it's not a one to one thing). But even so, a subpar air filter won't make the car run like it's missing half the cylinder banks.
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2021 GLB250 FWD, 2023 GLA250 FWD, 2013 C250, 2015 GLK350, 2005 ML350SE, 2003 E320
The old filters I took out are the same, and it's just an air filter. It's not like I put in cheap sparks or eBay rotors; even a bad air filter is usually pretty decent (and the good ones are often restrictive, so it's not a one to one thing). But even so, a subpar air filter won't make the car run like it's missing half the cylinder banks.
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I don't see this being an air filter problem. You should be able to idle and drive just fine with no filter installed. The MAF is measuring the air flow. Even at wide open throttle, without an air filter, you would probably get a bit more air flow than with a new filter but I doubt it would be anything past the abilities of the system to measure and compensate for.
Not recommending anyone drive without an air filter but I think the problem is elsewhere. Loose/bad connection at the MAF? At the intake air temperature sensor? At the MAP, if it has one?
OP: Did you happen to clean the MAF or throttle body with a spray? Since it's not a K&N filter I'm sure you didn't oil the new one. Possible vacuum leak as calder-cay mentioned? Forgot to re-attach some small vacuum hose?
Not recommending anyone drive without an air filter but I think the problem is elsewhere. Loose/bad connection at the MAF? At the intake air temperature sensor? At the MAP, if it has one?
OP: Did you happen to clean the MAF or throttle body with a spray? Since it's not a K&N filter I'm sure you didn't oil the new one. Possible vacuum leak as calder-cay mentioned? Forgot to re-attach some small vacuum hose?
Last edited by MBKLUE; Sep 25, 2025 at 11:52 AM.
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2013 glk 350
Yes air filter isn’t the issue , run it without the filter and see. I think you did something else by mistake when changing it. Or try the old filter
Last edited by Mmr1; Sep 25, 2025 at 11:18 AM.
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I don't see this being an air filter problem. You should be able to idle and drive just fine with no filter installed. The MAF is measuring the air flow. Even at wide open throttle, without an air filter, you would probably get a bit more air flow than with a new filter but I doubt it would be anything past the abilities of the system to measure and compensate for.
Not recommending anyone drive without an air filter but I think the problem is elsewhere. Loose/bad connection at the MAF? At the intake air temperature sensor? At the MAP, if it has one?
Did you happen to clean the MAF or throttle body with a spray? Since it's not a K&N filter I'm sure you didn't oil the new one. Possible vacuum leak as calder-cay mentioned? Forgot to re-attach some small vacuum hose?
Not recommending anyone drive without an air filter but I think the problem is elsewhere. Loose/bad connection at the MAF? At the intake air temperature sensor? At the MAP, if it has one?
Did you happen to clean the MAF or throttle body with a spray? Since it's not a K&N filter I'm sure you didn't oil the new one. Possible vacuum leak as calder-cay mentioned? Forgot to re-attach some small vacuum hose?
OP seems to have tried putting the old filter back same issue.
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The OP could certainly try idling or driving the car (in a clean environment for a short distance) without an air filter(s) as Mmr1 mentioned. I think it will make no difference but a good test just to eliminate a possible cause, if nothing else.
Last edited by MBKLUE; Sep 25, 2025 at 11:35 AM.
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Makes sense. Wish OP can tell us more once a scanner is plugged in.
