M157 Bucking/Idle Issues...Help Needed
03-21-2016, 03:43 PM
#26
MBWorld Fanatic!
i used this one...will pay for itself on the first use as cost is cheaper than one dealer diagnostic scan 
https://jet.com/product/detail/ebc00...t4gaAjuY8P8HAQ
https://jet.com/product/detail/ebc00...t4gaAjuY8P8HAQ
Under $30
You will need an App for your ios or android device... another $5 or so.
03-21-2016, 05:23 PM
#27
wont read a lot of mercedes codes. I have a generic OBD scanner that is mostly useless on my E55 or E63. I also have a Star Diagnostic scanner so I do compare side by side
03-21-2016, 05:30 PM
#29
Hi all,
Just wanted to get your feedback on a few issues I've been having with the car. Also posting this in the E forum since you guys are so much more after than our CLS area.
Current performance mods are as follows:
Eurocharged Tune Stage 2 (24lbs. boost)
Weistec Bosch Silver Plugs
K&N Filters
Straight Pipes
93 octane
I've been getting pretty significant "bucking" that I've seen described here on initial throttle-tip in when the motor is below operating temp. Especially on colder or low humidity days. Has anyone figured out a resolution to this? I've also tried fuel system cleaner and that helped but only for a week or so before it came back.
I've also seen my engine rev ever so slightly on it's own here and there. Just a little jump off idle. It happens very rarely and thus very difficult to capture on video. Always while in drive, usually with my foot on the brake stopped at a light or something.
Also, does anyone have any throttle tip-in lag when the car is up to operating temp? My car is Jeckle and Hyde when the engine is cold versus warm. Super sensitive throttle when cold and laggy when warm. I do TCU resets pretty often because most of my driving is city driving on cold motor which is obviously terrible for responsive, quick shifts.
Last question, does anyone notice that their car seems to choke for air upon WOT? During highway WOT, I feel like the car is struggling to redline almost like their is resistance, perhaps not getting enough air or something along those lines?
I'm sending my ECU back to Eurocharged to have them look at the A/F ratios any other data logged in the next 2 weeks. I'm hoping they can help diagnose these issues.
Appreciate anyone's feedback, advice or questions.
Thanks!
Just wanted to get your feedback on a few issues I've been having with the car. Also posting this in the E forum since you guys are so much more after than our CLS area.
Current performance mods are as follows:
Eurocharged Tune Stage 2 (24lbs. boost)
Weistec Bosch Silver Plugs
K&N Filters
Straight Pipes
93 octane
I've been getting pretty significant "bucking" that I've seen described here on initial throttle-tip in when the motor is below operating temp. Especially on colder or low humidity days. Has anyone figured out a resolution to this? I've also tried fuel system cleaner and that helped but only for a week or so before it came back.
I've also seen my engine rev ever so slightly on it's own here and there. Just a little jump off idle. It happens very rarely and thus very difficult to capture on video. Always while in drive, usually with my foot on the brake stopped at a light or something.
Also, does anyone have any throttle tip-in lag when the car is up to operating temp? My car is Jeckle and Hyde when the engine is cold versus warm. Super sensitive throttle when cold and laggy when warm. I do TCU resets pretty often because most of my driving is city driving on cold motor which is obviously terrible for responsive, quick shifts.
Last question, does anyone notice that their car seems to choke for air upon WOT? During highway WOT, I feel like the car is struggling to redline almost like their is resistance, perhaps not getting enough air or something along those lines?
I'm sending my ECU back to Eurocharged to have them look at the A/F ratios any other data logged in the next 2 weeks. I'm hoping they can help diagnose these issues.
Appreciate anyone's feedback, advice or questions.
Thanks!
I wonder if you are getting a lot of spark blow out even at low rpm where you are most likely getting the most boost at aggressive tip in.
With that amount of boost you certainly need to gap down to 0.020-0.022 max!
Last edited by kponti; 03-22-2016 at 09:03 PM.
03-21-2016, 05:33 PM
#30
MBWorld Fanatic!
Join Date: Feb 2011
Location: miami / delray beach
Posts: 2,841
Received 201 Likes
on
154 Posts
2014 E63s amg 4matic, 2009 C63, 2006 E55 AMG , 2001.5 AUDI S4 stg 3+ w/meth
yeah those generic bluetooth ones are pretty much worthless on mercs.... had one and threw it away as it would never even connect
03-21-2016, 05:44 PM
#31
MBWorld Fanatic!
Haven't had to connect it yet to the T&C or the SL63.
03-22-2016, 10:02 AM
#32
Super Member
Thread Starter
In all honesty I thought most tunes are only 18.8psi? I know Renntech maxes out around 19 or so psi (eliminating the 18.8 to 14.5 drop). This seems like a lot of boost being asked for.
I wonder if you are getting a lot of spark blow out even at low rpm where you are most likely getting the most boost at aggressive tip in.
With that amount of boost you certainly need to gap down to 0.0020-0.0022 max!
I wonder if you are getting a lot of spark blow out even at low rpm where you are most likely getting the most boost at aggressive tip in.
With that amount of boost you certainly need to gap down to 0.0020-0.0022 max!
Ironically, I did get my first ever CEL this morning. I did just get gas 2 days ago, so I'm wondering if it's a gas cap CEL. Car runs fine though.
03-22-2016, 10:30 AM
#33
MBWorld Fanatic!
Join Date: Feb 2011
Location: miami / delray beach
Posts: 2,841
Received 201 Likes
on
154 Posts
2014 E63s amg 4matic, 2009 C63, 2006 E55 AMG , 2001.5 AUDI S4 stg 3+ w/meth
as i mentioned earlier, in regard to the idle jumping and stumbling, that it usually takes a little while for CEL to pop up.... now that it has even more convinced its misfiring due to plugs... pull them and check the gaps and electrodes
03-22-2016, 10:51 AM
#34
Super Member
Thread Starter
Anyone know what a dealer plug change costs? $400-500? It's not something I have the capability to myself (living in an apartment with no garage or space to work).
I will keep everyone posted.
03-22-2016, 12:39 PM
#35
The car is going in Thursday for a software fix on the bucking. They will also scan for codes and see what they find. If they find any misfires, I will have them change out the plugs.
Anyone know what a dealer plug change costs? $400-500? It's not something I have the capability to myself (living in an apartment with no garage or space to work).
I will keep everyone posted.
Anyone know what a dealer plug change costs? $400-500? It's not something I have the capability to myself (living in an apartment with no garage or space to work).
I will keep everyone posted.
Now you gotta do this or do not waste your money changing the plugs:
Get the plugs they will use in the swap; Close the gaps to 0.021-0.022; Hand them back over to SA or Tech to be installed.
If you do not do the above or at least ask them to do the gaps for you, do not waste your time or money swapping plugs. It will not solve your problem and a month from now you will be back here asking for help on the same issue. My first misfire came about 100miles after a set of fresh stock plugs
03-22-2016, 01:04 PM
#36
MBWorld Fanatic!
Join Date: Feb 2011
Location: miami / delray beach
Posts: 2,841
Received 201 Likes
on
154 Posts
2014 E63s amg 4matic, 2009 C63, 2006 E55 AMG , 2001.5 AUDI S4 stg 3+ w/meth
mine have been gaped at stock gap on renntech tune and no problem for 4 months. my cousin has weistec tune for a year now and not one issue on stock gaped plugs
tunes do not add really anymore boost than stock tune, they just hold the boost longer instead of tapering it off like stock tune does
its not like tunes are increasing the boost from 18.8 psi to 30 psi lol
Any closing the plug gap down to get it to fire at high boost / high rpm is a band aid. narrow spark plug gap would require less voltage to spark, but the spark might be too small and weak to ignite and consume the fuel-air mixture in the time available for the ignition phase of otto cycle. Most experienced tuners know that opening the gap up to present a larger spark to the air/fuel mixture maximizes burn efficiency, however, after they have raised compression and installed a turbo, they have to lower the gap (to ensure ignitability in the denser air/fuel mixtures). It is for this reason that most racers add high power ignition systems. The added power allows them to reopen the gap without misfire.
The A/F mixture isn't 100% homogeneous inside of the cylinder. There are areas it is leaner than it should be and areas that it is richer. A wider plug gap is exposes more spark to more of the mixture. Once lit, the mixture is lit. There is no risk of an incomplete burn, due to plug gap. The concern is whether the mixture will be ignited or not. Also, small gaps are more subject to being closed up, shorted, by depositsor other foreign material lodging in the gap
now if you get a weistec W4 1000+hp kit, then sure different plugs/gap will come into play
tunes do not add really anymore boost than stock tune, they just hold the boost longer instead of tapering it off like stock tune does
its not like tunes are increasing the boost from 18.8 psi to 30 psi lol
Any closing the plug gap down to get it to fire at high boost / high rpm is a band aid. narrow spark plug gap would require less voltage to spark, but the spark might be too small and weak to ignite and consume the fuel-air mixture in the time available for the ignition phase of otto cycle. Most experienced tuners know that opening the gap up to present a larger spark to the air/fuel mixture maximizes burn efficiency, however, after they have raised compression and installed a turbo, they have to lower the gap (to ensure ignitability in the denser air/fuel mixtures). It is for this reason that most racers add high power ignition systems. The added power allows them to reopen the gap without misfire.
The A/F mixture isn't 100% homogeneous inside of the cylinder. There are areas it is leaner than it should be and areas that it is richer. A wider plug gap is exposes more spark to more of the mixture. Once lit, the mixture is lit. There is no risk of an incomplete burn, due to plug gap. The concern is whether the mixture will be ignited or not. Also, small gaps are more subject to being closed up, shorted, by depositsor other foreign material lodging in the gap
now if you get a weistec W4 1000+hp kit, then sure different plugs/gap will come into play
Last edited by gaspam; 03-22-2016 at 01:29 PM.
03-22-2016, 01:34 PM
#37
Super Member
Thread Starter
Thank you both for your feedback on the gapping. I'm pretty sure they dealer will not allow me to manipulate the gapping on the plugs or do anything other than the stock gapping if they are going to install them. As long as they are properly indexed, I'm told with the newer, improved OEM plugs, I should be fine. That's what I'm hoping for at least.
03-22-2016, 01:37 PM
#38
MBWorld Fanatic!
Join Date: Feb 2011
Location: miami / delray beach
Posts: 2,841
Received 201 Likes
on
154 Posts
2014 E63s amg 4matic, 2009 C63, 2006 E55 AMG , 2001.5 AUDI S4 stg 3+ w/meth
they told me stock plugs/ gap are fine unless going to a bigger turbo kit
03-22-2016, 02:32 PM
#39
Please report back in a month or less.....I had the Renntech tune for less than 3 months and brand new dealer installed plugs a week after the tune....misfired occasionally. It started to get a bit more frequent with time.
Changed again to closer gap and not even a hint of a misfire
Interestingly, I never had a misfire with my 30k miles stock plugs
Changed again to closer gap and not even a hint of a misfire
Interestingly, I never had a misfire with my 30k miles stock plugs
03-22-2016, 04:38 PM
#40
Quick note, the myth of the "new and improved" spark plugs is just that, a myth. I have all the service records of my car from date of delivery and there was no record of the spark plugs being replaced.
After my two plug replacements, I compared the 2012 stockers to the two sets of new ones (2016) I have and they were exactly the same! In fact I can post pictures of all 16 plugs on here and you will be hard pressed to find any differences (yes I know there could be internal differences but I doubt it)
After my two plug replacements, I compared the 2012 stockers to the two sets of new ones (2016) I have and they were exactly the same! In fact I can post pictures of all 16 plugs on here and you will be hard pressed to find any differences (yes I know there could be internal differences but I doubt it)
Last edited by kponti; 03-22-2016 at 04:43 PM.
03-23-2016, 02:11 PM
#42
MBWorld Fanatic!
Join Date: Feb 2011
Location: miami / delray beach
Posts: 2,841
Received 201 Likes
on
154 Posts
2014 E63s amg 4matic, 2009 C63, 2006 E55 AMG , 2001.5 AUDI S4 stg 3+ w/meth
https://mbworld.org/forums/w218/4411...ug-recall.html
Last edited by gaspam; 03-23-2016 at 02:24 PM.
03-23-2016, 02:18 PM
#43
MBWorld Fanatic!
For OEM plugs follow OEM torque specs. As for other plugs, not sure how you would know without taking the head off. Back in the day we used to use plug shims with the head on a bench to setup the plugs the way we wanted.
03-23-2016, 02:32 PM
#44
there was a VIN specific recall on original plugs.... so there is a new version spark plug... basically short story is there was a batch of bad plugs that had manufacturer defect that affected early 5.5TT's
https://mbworld.org/forums/w218/4411...ug-recall.html
https://mbworld.org/forums/w218/4411...ug-recall.html
03-23-2016, 02:43 PM
#45
MBWorld Fanatic!
Join Date: Feb 2011
Location: miami / delray beach
Posts: 2,841
Received 201 Likes
on
154 Posts
2014 E63s amg 4matic, 2009 C63, 2006 E55 AMG , 2001.5 AUDI S4 stg 3+ w/meth
that bad batch was quite large on all the originally m157's which prompted m157 owners to look for new plugs and renntech to come out with its own plug.... once it was revealed that the original plug problems people were having was actually due to defective plug batch, people stopped buying the renntech plugs and they discontinued them since the new "non-defective" plugs were having no problems
consider "new improved plugs" as "non-defective plugs"
there are a bunch of threads on this from back in 2012
consider "new improved plugs" as "non-defective plugs"
there are a bunch of threads on this from back in 2012
Last edited by gaspam; 03-23-2016 at 02:51 PM.
03-23-2016, 03:54 PM
#46
that bad batch was quite large on all the originally m157's which prompted m157 owners to look for new plugs and renntech to come out with its own plug.... once it was revealed that the original plug problems people were having was actually due to defective plug batch, people stopped buying the renntech plugs and they discontinued them since the new "non-defective" plugs were having no problems
consider "new improved plugs" as "non-defective plugs"
there are a bunch of threads on this from back in 2012
consider "new improved plugs" as "non-defective plugs"
there are a bunch of threads on this from back in 2012
Also this is not limited to the m157, the m278 also has had lots of misfire problems (yes same plugs used)
03-25-2016, 01:02 PM
#47
Super Member
Thread Starter
Hi all, just an update. This whole issue is being attributed to a temperature gauge related issue. That what was throwing the recent CEL as well. It was reading temps wrong and apparently causing other issues along with the bucking. They are still conducting more tests but I just wanted to share an update. I'm having them check the plugs as well just to be safe.
Definitely not the answer I was expecting to hear!
Definitely not the answer I was expecting to hear!
03-25-2016, 01:10 PM
#48
I hope that's what it is. I can say from previous experience that a bad temp sensor can make your car go wonky so it is very possible. However a gauge sensor....that I am not so sure about.
Mine was attributed to a accelerator pedal and module reading high, they were both perfectly fine until I got a tune lol. Less than a week later, the coils were to blame.
Mine was attributed to a accelerator pedal and module reading high, they were both perfectly fine until I got a tune lol. Less than a week later, the coils were to blame.
03-25-2016, 01:11 PM
#49
Super Member
Thread Starter
I hope that's what it is. I can say from previous experience that a bad temp sensor can make your car go wonky so it is very possible. However a gauge sensor....that I am not so sure about.
Mine was attributed to a accelerator pedal and module that were perfectly fine until I got a tune lol. Less than a week later, it was the coils were to blame.
Mine was attributed to a accelerator pedal and module that were perfectly fine until I got a tune lol. Less than a week later, it was the coils were to blame.
Interesting to hear about your other issues though. We will see how far down this rabbit hole I have to go...
03-25-2016, 01:14 PM
#50
The good news is, with my warranty expiring in 6 days, I got the ticket open. So if the problem creeps back up after my warranty expires, I'm still covered. So we will see.
Interesting to hear about your other issues though. We will see how far down this rabbit hole I have to go...
Interesting to hear about your other issues though. We will see how far down this rabbit hole I have to go...
In my case, I do not believe any of those things were the cause, just the typical dealer throwing parts at the car till something sticks
