2010 GLK plastic engine covers cause codes and rough idle?
Thread Starter
Junior Member
Joined: Apr 2021
Posts: 26
Likes: 5
From: Mill Creek, WA
GLK 350
2010 GLK plastic engine covers cause codes and rough idle?
Might be a dumb question...but still learning Mercedes...and I'm also dumb. Not a good combo.
Can the rear engine cover not being snapped down correctly cause codes and rough idle? I get that it oddly secures down onto the intake and MAF spot, so it would make sense that it "could".
I've had rough sitting idle and rougher while in gear idle....deep scan revealed codes my OBD didn't.
0620 Check intake tract for unmetered air
0750 Self adaptation of mixture formation for enleanment at idle for the left cylinder bank is below permissible limit (Seems like P0175 too rich)
2096 The mixture in the left cylinder bank is too rich when idling
0746 Self adaptation of mixture formation for enleanment at idle for the right cylinder bank is below permissible limit (Seems like P0172 too rich other bank)
2092 The mixture in the right cylinder bank is too rich when idling
Shop says it was not seated properly....so i'm gonna drive it and see if it performs any better in idle conditions. Any thoughts? And please remember, take it easy on me...as stated, I'm stupid.
Thanks!
Jason
Can the rear engine cover not being snapped down correctly cause codes and rough idle? I get that it oddly secures down onto the intake and MAF spot, so it would make sense that it "could".
I've had rough sitting idle and rougher while in gear idle....deep scan revealed codes my OBD didn't.
0620 Check intake tract for unmetered air
0750 Self adaptation of mixture formation for enleanment at idle for the left cylinder bank is below permissible limit (Seems like P0175 too rich)
2096 The mixture in the left cylinder bank is too rich when idling
0746 Self adaptation of mixture formation for enleanment at idle for the right cylinder bank is below permissible limit (Seems like P0172 too rich other bank)
2092 The mixture in the right cylinder bank is too rich when idling
Shop says it was not seated properly....so i'm gonna drive it and see if it performs any better in idle conditions. Any thoughts? And please remember, take it easy on me...as stated, I'm stupid.
Thanks!
Jason
Thread Starter
Junior Member
Joined: Apr 2021
Posts: 26
Likes: 5
From: Mill Creek, WA
GLK 350
Doing a ton more research....my guess is a vacuum leak somewhere "AFTER" the MAF sensor. That would seemingly be "too lean" codes with the unmetered air code, which was throwing me off....but looking further too rich can be due to the ECM reading the 02 sensors downstream and detecting too much air in the mix....causing the order for more more fuel. I think i'm on to something! I'll keep this updated with any findings or resolution just for future help to others....
-Jason
-Jason
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Joined: Jul 2021
Posts: 8
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From: Ontario
2012 GLK350 4MATIC
Krieg17 did you solve your problem?
I will be sending my benz to my mechanic to have several parts on my GLK350 replaced, like the Secondary Air Pump, R & L Check valves (air diverter valves), and relay which all have a role in the Emissions and Fuel ratio.
"The system works by using an air pump to inject fresh air into the cylinders to lean out the rich fuel mixture that occurs during engine startup. This increases combustion temperatures, which in turn decreases catalyst warm up time, thus ensuring cleaner emissions during a cold start."
(https://www.germanautorepairshop.com/blog/)
This all started when my glk occasionally had a rough idle on cold or damp days, and now my secondary air pump makes a loud whining noise upon cold start every morning.
I hope this helps?
I will be sending my benz to my mechanic to have several parts on my GLK350 replaced, like the Secondary Air Pump, R & L Check valves (air diverter valves), and relay which all have a role in the Emissions and Fuel ratio.
"The system works by using an air pump to inject fresh air into the cylinders to lean out the rich fuel mixture that occurs during engine startup. This increases combustion temperatures, which in turn decreases catalyst warm up time, thus ensuring cleaner emissions during a cold start."
(https://www.germanautorepairshop.com/blog/)
This all started when my glk occasionally had a rough idle on cold or damp days, and now my secondary air pump makes a loud whining noise upon cold start every morning.
I hope this helps?
Thread Starter
Junior Member
Joined: Apr 2021
Posts: 26
Likes: 5
From: Mill Creek, WA
GLK 350
Thanks for the reply...still gotta get it in, been trying to edu-ma-cate or fix myself before doing so. So, no...no fix yet...still leaning towards a vacuum leak. Did the carb cleaner vacuum leak detection trick and found none though. I have gotten too rich and too lean codes as well. Something is up...maybe time to replace the MAF and O2 sensors....or just take it in and get the smoke test first. Secondary air pump was replaced 3 months before I bought it and that comes on and goes off later, so don't think it's that. But who knows....keep posting in here brother when you find your problem, I'm curious to know on that as well. I will update with any findings/fixes as well to help us all out.
If secondary pump is whining, that sounds like a problem...does it come on and shut off properly after 20 seconds or so?
If secondary pump is whining, that sounds like a problem...does it come on and shut off properly after 20 seconds or so?
Last edited by krieg17; Aug 12, 2021 at 08:45 PM.
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X204 GLK 3.0 m272.948 year 2010
Might be a dumb question...but still learning Mercedes...and I'm also dumb. Not a good combo.
Can the rear engine cover not being snapped down correctly cause codes and rough idle? I get that it oddly secures down onto the intake and MAF spot, so it would make sense that it "could".
I've had rough sitting idle and rougher while in gear idle....deep scan revealed codes my OBD didn't.
0620 Check intake tract for unmetered air
0750 Self adaptation of mixture formation for enleanment at idle for the left cylinder bank is below permissible limit (Seems like P0175 too rich)
2096 The mixture in the left cylinder bank is too rich when idling
0746 Self adaptation of mixture formation for enleanment at idle for the right cylinder bank is below permissible limit (Seems like P0172 too rich other bank)
2092 The mixture in the right cylinder bank is too rich when idling
Shop says it was not seated properly....so i'm gonna drive it and see if it performs any better in idle conditions. Any thoughts? And please remember, take it easy on me...as stated, I'm stupid.
Thanks!
Jason
Can the rear engine cover not being snapped down correctly cause codes and rough idle? I get that it oddly secures down onto the intake and MAF spot, so it would make sense that it "could".
I've had rough sitting idle and rougher while in gear idle....deep scan revealed codes my OBD didn't.
0620 Check intake tract for unmetered air
0750 Self adaptation of mixture formation for enleanment at idle for the left cylinder bank is below permissible limit (Seems like P0175 too rich)
2096 The mixture in the left cylinder bank is too rich when idling
0746 Self adaptation of mixture formation for enleanment at idle for the right cylinder bank is below permissible limit (Seems like P0172 too rich other bank)
2092 The mixture in the right cylinder bank is too rich when idling
Shop says it was not seated properly....so i'm gonna drive it and see if it performs any better in idle conditions. Any thoughts? And please remember, take it easy on me...as stated, I'm stupid.
Thanks!
Jason
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Thread Starter
Junior Member
Joined: Apr 2021
Posts: 26
Likes: 5
From: Mill Creek, WA
GLK 350
Seriously? Wow...maybe there is something to it not seating properly onto the MAF. It is a very stupid design if you ask me.....I thanks you for the reply. So just making sure it was seated properly actually helped the rough idle and some codes? I have had too rich, and lastly "unmetered air", which to me equals air getting in AFTER the MAF....who knows! But now what's funny...now I'm getting too lean codes...it has always been too rich before this. Wonder if it's time to just spend $100 and replace the MAF? (it's already been cleaned) and or 02 sensors ....My codes are all over the place with lean/rich/unmetered air once....but i guess a vacuum leak could still cause a lot of this mess. Thoughts?
Newbie
Joined: Aug 2021
Posts: 5
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X204 GLK 3.0 m272.948 year 2010
Seriously? Wow...maybe there is something to it not seating properly onto the MAF. It is a very stupid design if you ask me.....I thanks you for the reply. So just making sure it was seated properly actually helped the rough idle and some codes? I have had too rich, and lastly "unmetered air", which to me equals air getting in AFTER the MAF....who knows! But now what's funny...now I'm getting too lean codes...it has always been too rich before this. Wonder if it's time to just spend $100 and replace the MAF? (it's already been cleaned) and or 02 sensors ....My codes are all over the place with lean/rich/unmetered air once....but i guess a vacuum leak could still cause a lot of this mess. Thoughts?
So my advice for you is to carefully watch and listen the whole intake system, even without the plastic cover on MAF - it is easier to hear any leaks.
Couple tips - maybe some would be helpful.
Thread Starter
Junior Member
Joined: Apr 2021
Posts: 26
Likes: 5
From: Mill Creek, WA
GLK 350
Ahhh, yeah i see that....nice find by you! Probably made a world of difference for you That's kinda what i'm thinking, air is getting in somewhere.....i sprayed carb cleaner all around after starting and on a cold engine...i was unable to find any spots where the engine revved or lowered. So if there's a leak, i have been unable to find it! Wonder if ponying up to take it somewhere w/ a smoke machine is right call at this point.
Thanks again!
Jason
Thanks again!
Jason
Newbie
Joined: Jul 2021
Posts: 8
Likes: 0
From: Ontario
2012 GLK350 4MATIC
Thanks for the reply...still gotta get it in, been trying to edu-ma-cate or fix myself before doing so. So, no...no fix yet...still leaning towards a vacuum leak. Did the carb cleaner vacuum leak detection trick and found none though. I have gotten too rich and too lean codes as well. Something is up...maybe time to replace the MAF and O2 sensors....or just take it in and get the smoke test first. Secondary air pump was replaced 3 months before I bought it and that comes on and goes off later, so don't think it's that. But who knows....keep posting in here brother when you find your problem, I'm curious to know on that as well. I will update with any findings/fixes as well to help us all out.
If secondary pump is whining, that sounds like a problem...does it come on and shut off properly after 20 seconds or so?
If secondary pump is whining, that sounds like a problem...does it come on and shut off properly after 20 seconds or so?
I have been doing research myself to better understand my air pump issue which lead me to replacing the diverter valves. The whining is only while the pump is running at the begining of a cold start so it is working, just not properly. Through reading about the secondary air pump problems & figuring out what to do I have found that you need to replace the relay fuse when you replace the secondary air pump. Also found that the pump commonly fails because one or both diverter valves has buildup, sometimes ice in colder conditions. You mentioned your pump was replaced 3 months before you got it, did they look at other related parts that possibly should have been replaced? Or why the pump needed to be replaced?
Here is a diagram of the A.I.R. System:
https://www.mboemparts.com/v-2012-me...--a-i-r-system
This one just helps explain the check valves, but you need to scroll down past the sales pitch/estimator stuff:
https://repairpal.com/estimator/merc...placement-cost
I'm just spit balling, but I wonder if your tests for lean or rich would have different results depending on when you test? Like at cold start compared to a warmer engine?
