Hesitation on highway slope??
my blower doesnt like the KNs at all. It bucks and hesitates.
I run stock filters with charcoals and it runs perfect. Must be reversion or the maf doesnt get a good reading with the other filters.
I had a similar issue with a K&N on my 928. Apparently small droplets of the oil on the K&N hit the hot sensor wire on the MAF, which screws up the metering (you can actually kill the MAF if it comes in contact with too much oil). Once you remove the K&N, there's a good chance you'll burn off the oil on the sensor wire and it starts to properly meter the air again.
I had a similar issue with a K&N on my 928. Apparently small droplets of the oil on the K&N hit the hot sensor wire on the MAF, which screws up the metering (you can actually kill the MAF if it comes in contact with too much oil). Once you remove the K&N, there's a good chance you'll burn off the oil on the sensor wire and it starts to properly meter the air again.
So if I were looking to purchase an aftermarket air filter, does that mean I should go with the Weistec High Flow, because it is dry?
I had a similar issue with a K&N on my 928. Apparently small droplets of the oil on the K&N hit the hot sensor wire on the MAF, which screws up the metering (you can actually kill the MAF if it comes in contact with too much oil). Once you remove the K&N, there's a good chance you'll burn off the oil on the sensor wire and it starts to properly meter the air again.
except me. I am using the Weistec filters, which have been running flawlessly at WOT until about a week ago. this implies that something has built up or occurred where previous there was no problem. other people are using the AFE dry filters without a prob as well.
for the record, I emailed weistec asking for suggestions. i hope they can take the time to share their input even though it is a pretty low dollar mod.
Last edited by _timothy; Jul 24, 2013 at 07:09 AM.
Not familiar with the Weistec filters - if it's dry then it may very well be something else (hell, even if you were all using K&N it could still be something else). Just threw it out there because I am one of the people that has killed a MAF specifically because of the K&N oil hitting the hot wire, and the symptoms were quite similar (MAF unable to properly meter the air -> ECU plays havoc with the AFR so you get stuttering and hesitation). Timothy, are you saying that people running the AFE dry filters are also having the same issue? If yes, that would indicate a problem with something else.
EDIT: Or like 1st AMG said it could be the air filters / housings again if they're clogged and/or you somehow create a low pressure in the airbox (insufficient air), or have unmetered air going into the engine although I can't see how this would be caused by the filter itself(even if you take out the filters completely, all the air going in still has to pass by the MAF so the leak (unmetered air coming in) would have to be somewhere past that point).
Last edited by Diabolis; Jul 24, 2013 at 02:47 PM.
for the record, I emailed weistec asking for suggestions. i hope they can take the time to share their input even though it is a pretty low dollar mod.
Timothy, what does the car do in WOT now? How has it changed from before? Finally, how long did it run well before having issues? These will help us and the community understand what is going on here.
For those running K&N filters... Many customers ran this filter and eventually oiled down the MAF's. This can be cleaned but the reading can be off making the car run bad.
The other part about K&N filters that the community needs to know about... These filters are designed to be ran with oil. You cannot simply wash these filters and run them with no oil. They will not provide sufficient filtration of debris.
A dry filter on the other hand is designed to be ran with no oils. They typically have more weaving and the actual weave design is different. We know this is a small dollar item but there needs to be a lot of thought put into an air filter since it is purchased in such high quantities.
The actual problem many of you are seeing is the MAF not getting a good reading and the car starts to buck or hesitate. This typically only occurs at high load, low-mid RPM range but a few of you are having it in WOT which is surprising.
For those having this issue, which are boxes are you running? We might be able to have a correlation on this if we can understand the air box as well. Thanks guys.
Weistec Engineering
Possibly a related issue.
Charcoals removed, AFe filters, OE air box.
The Best of Mercedes & AMG
Serge laughed and said "f***ing K&N's"
ran fine without the blower except a few times in lower rpm high gear rolls it would hesitate a bit.
these are two different cars as well.
im running stock box with stock fikter and charcosl and it runs strong no problems.




So remove K&N on stock set up even with no trouble???
I have no idea what a C63 MAF sells for or whether it can be cleaned or have the platinum hot wire replaced and recalibrated, but if it's anywhere in the range as the 928 MAF ($1K+), *I* wouldn't take the chance. MB almost certainly wouldn't swallow the cost either - they'll probably tell you that you have voided the warranty.
For those running K&N filters... Many customers ran this filter and eventually oiled down the MAF's. This can be cleaned but the reading can be off making the car run bad.
The other part about K&N filters that the community needs to know about... These filters are designed to be ran with oil. You cannot simply wash these filters and run them with no oil. They will not provide sufficient filtration of debris.
A dry filter on the other hand is designed to be ran with no oils. They typically have more weaving and the actual weave design is different. We know this is a small dollar item but there needs to be a lot of thought put into an air filter since it is purchased in such high quantities.
The actual problem many of you are seeing is the MAF not getting a good reading and the car starts to buck or hesitate. This typically only occurs at high load, low-mid RPM range but a few of you are having it in WOT which is surprising.
For those having this issue, which are boxes are you running? We might be able to have a correlation on this if we can understand the air box as well. Thanks guys.
Weistec Engineering
I misphrased the post you quoted. This really occurs just shy of WOT, not at WOT. I will be in 3rd or 4th at around 4-5k RPMs and 3/4 throttle applied. The car will suddenly lurch and hesitate as if fuel has been cut off but I don't get any dash lights/messages and no CEL. I lay off and everything seems to be normal.
Today, I drove through my wormhole into mexico and did 2-3-4 WOT in S+ all the way to 5th and there was no issue to try to "test" other conditions. I'll try tomorrow at 3/4 throttle from 3-4 and see if it happens again. It started happening for the first time about a week or so ago. I didn't think anything of it at that point.. but now its recurring and I am a little concerned.
My mods are MB ROW airboxes, no charcoal, your filters, secondary cat delete, and a tune and they worked in total harmony for a bit over 6 months without any issue from the get-go. This weekend I will definitely reseat the airboxes although I am rather puzzled if that turns out to be the issue since I haven't touched anything under the hood in 6-7k miles beyond checking oil. It has been extraordinarily humid here lately as well.
Last edited by _timothy; Jul 24, 2013 at 10:03 PM.
I misphrased the post you quoted. This really occurs just shy of WOT, not at WOT. I will be in 3rd or 4th at around 4-5k RPMs and 3/4 throttle applied. The car will suddenly lurch and hesitate as if fuel has been cut off but I don't get any dash lights/messages and no CEL. I lay off and everything seems to be normal.
Today, I drove through my wormhole into mexico and did 2-3-4 WOT in S+ all the way to 5th and there was no issue to try to "test" other conditions. I'll try tomorrow at 3/4 throttle from 3-4 and see if it happens again. It started happening for the first time about a week or so ago. I didn't think anything of it at that point.. but now its recurring and I am a little concerned.
My mods are MB ROW airboxes, no charcoal, your filters, secondary cat delete, and a tune and they worked in total harmony for a bit over 6 months without any issue from the get-go. This weekend I will definitely reseat the airboxes although I am rather puzzled if that turns out to be the issue since I haven't touched anything under the hood in 6-7k miles beyond checking oil. It has been extraordinarily humid here lately as well.
Anyway, exact same thing for me. WOT is perfect. Anything 50-90%, in any gear (usually 2 or 3 given normal travel speeds) causes lurching and bucking around 5k rpm. I found an easy way to duplicate it at reasonable speed is put the car in M2 or S2 and give it the right throttle. It should replicate it fairly easily when the tach hits 5k or so. Here's a vid of mine. You can hear the sound clearly, and see my phone lurch from the hesitation.
http://www.youtube.com/watch?v=TTPKX...ature=youtu.be

The problems you guys having only coming in the facelift cars with the mct trans? Wonder if it's a "trans tuning" issue instead of fuel/spark/air??
I ask because I'm having same issue with my modded Cummins.
But I'm positive that it's troubles are trans tune related, nothing related to the engine enhancements..
Check engine light come on tonight codes p2626 and p2414 came up
I reset them took it for a thrash and nothing
When I let the car sit for 2 days and then jump in again it throws a code
Do u think my oxy sensors are gone
Check engine light come on tonight codes p2626 and p2414 came up
I reset them took it for a thrash and nothing
When I let the car sit for 2 days and then jump in again it throws a code
Do u think my oxy sensors are gone
If you see 2 post above i was having the same issues and it was right after i did long tubes which i thought caused the issue but it wasnt as soon as i replaced it the car ran awesome and has been rock solid since. I also got multiple misfires a day after posting that and the car would go into limp mode. When we diagnosed the car it ended being a combo of the 02 sensor and my variable intake actuator has been stuck closed causing alot less air up top than the computer was expecting.







