HELP!--Shuddering When Under Heavy Throttle (Part 2)

[Fresh1179]

I posted a while back about shuddering when under full or close to full throttle in 3rd, 4th, 5th, and 6th. This is intense shuddering, almost like multiple misfires or mistiming(?). I got some very helpful advice earlier about replacing the CV joint in the driveshaft, center support bearing, and driveshaft centering sleeve.

I took the car to the shop, and they checked these components and determined that it was not a drivetrain issue, but an engine running condition issue. I am going to try to supply as many facts as I can. I would note that although I did supply and inquire about the parts listed above, they were not replaced. The center support bearing and driveshaft centering sleeve have less than 250 miles on them, the CV is unknown, but likely original. The shop had the car for two weeks and could not figure out what was going on, so I am at a loss. Any help or guidance would be hugely appreciated.

Condition:
2006 E46 M3
Lessened Slightly When Engine is Warm
Hard Shuddering Under Heavy/Full Throttle in Predominently 4th, 5th, and 6th
Car Fails to Accelerate Under Shuddering Condition
When Throttle is lessened, shuddering stops and vehicle resumes proper acceleration

Related Vehicle Modifications:
Replaced Clutch and Attendant Parts Less than 250 Miles Ago
All Coils and Plugs Replaced
Flex Disc is New
Driveshaft Center Sleeve is New
Center Support Bearing Is New
Karbonius Airbox and "CSL" Conversion
Kassel "CSL Conversion" for 6MT
IAT Wired from MAF Delete into "Stock" Karbonius Location
TTFS Rail with MAP Sensor Wired to ECU
Beisan Full "Bulletproofing" Performed
Valve Adjustment Less than 2k Miles Ago
Rod Bearings Replaced
Radium Catch Can Installed

No hard codes are thrown, except the coolant temp sensor which failed during their testing. It was replaced.

I am happy to supply more information as needed. This is truly the first thing with this car that I just can't figure out. Also my heated mirrors are on all the time and extremely hot but that is another day...

Thanks Guys! 8.5.1

[eacmen]

Sorry I can't be much direct help. But it almost sounds like it might be a sensor or wiring issue. Sometimes tunes disable certain codes so they dont trigger a CEL. I sometimes flash the stock tune back on to get codes that would otherwise be supressed. Might need to reach out to Kassel to get some advice. Might need to get some data logging setup to figure it out though.

[SliM3]

Stock cams? Does it occur during rapid throttle actuation? If so, sounds like your accel enrichment maps are a tad rich. Same thing happens when I scale larger injectors before adjusting the maps. Though your set-up is different it sounds like the same condition.

[Fresh1179]

Stock cams? Does it occur during rapid throttle actuation? If so, sounds like your accel enrichment maps are a tad rich. Same thing happens when I scale larger injectors before adjusting the maps. Though your set-up is different it sounds like the same condition.

Yes, that is correct. When there is rapid throttle application the condition occurs. Slower, more progressive application does not cause the condition to occur. I do run the stock cams.

Edit: What is the course of action for mitigation or alleviating this issue?

[Slideways]

Who is the tuner? If everything else on your list checks out by either taking a second look at it or reverting to stock where possible, I'd suspect the wiring, the tune and the ECU in that order. Verify with software that the MAP sensor and air intake temp sensor are giving the correct data to the ECU.

[Fresh1179]

Prompt Response From Kassel

KASSEL "Is your calibration setup for the TTFS MAP?



This isn’t uncommon. It is typically caused from overfueling down low."

ME: "Correct, it is setup for that calibration. I believe that I specified TTFS map when I sent off for the conversion. Is there anything I can do to mitigate the issue?"

KASSEL: "You need a custom calibration to rectify the over fueling"



I had no idea this was not uncommon. It sounds like I will need to have some custom tuning done to rectify the situation. Oh well.

[heinzboehmer]

I wouldn't be surprised if what Kassel put on your DME is just the regular CSL tune with the VANOS offsets changed to match the stock cams. If so then yes, you'll need a custom tune, as the fuel maps are still setup for CSL cams.

[Fresh1179]

I wouldn't be surprised if what Kassel put on your DME is just the regular CSL tune with the VANOS offsets changed to match the stock cams. If so then yes, you'll need a custom tune, as the fuel maps are still setup for CSL cams.

Edit: I believe this is the case.

Sounds like a good excuse to pick up some $3000 Shrick Cams and followers. 😄

[BMWahba]

Edit: I believe this is the case.

Sounds like a good excuse to pick up some $3000 Shrick Cams and followers. 😄

I have a set of Schricks for sale....

[eacmen]

Most i've spoken too have had good things to say about Kassel.

But...if you're looking for options, I would reach out to Hassan with HTE performance. He can do dyno and non-dyno (logged) remote tunes.


Sent from my iPhone using Tapatalk

[HighOnLSB]

Can you describe the shuddering issue in more detail? I feel like I am chasing down a similar issue however I would describe mine as more of an engine hesitation or stalling at WOT. Just want to make sure it is in fact the same symptoms before providing more details and sidetracking the thread from your issue...

[antknee]

i know you mentioned you eliminated the fact that the guibo is bad, but it is possible they didn't install it properly.

This video shows how an improper installation of the guibo can create a rubber band backlash/shudder effect

https://www.youtube.com/watch?v=Vw7Zbp1rfGI

[Fresh1179]

Can you describe the shuddering issue in more detail? I feel like I am chasing down a similar issue however I would describe mine as more of an engine hesitation or stalling at WOT. Just want to make sure it is in fact the same symptoms before providing more details and sidetracking the thread from your issue...

I’ll try to do my best. It is essentially a violent shuddering (I can believe I have been using shuttering—windows) when the RPM’s are around 3-4K and full or mostly full throttle is applied. It causes the car to buck violently (imagine a earthquake) and not to accelerate. The RPM’s do not rise, and it sounds like the engine is failing to fire and a violent shuddering occurs through the drivetrain and in the cabin. If the throttle is reduced below %75 percent this is lessened. If it is lessened further the issue further reduces until it is non existent around %40 throttle. No codes are thrown.

[heinzboehmer]

i know you mentioned you eliminated the fact that the guibo is bad, but it is possible they didn't install it properly.

This video shows how an improper installation of the guibo can create a rubber band backlash/shudder effect

https://www.youtube.com/watch?v=Vw7Zbp1rfGI

"You following what I'm saying so far? If you don't -- hang it up. You should try a different hobby." Cracked up when he said that.

But that was a very informative video, thanks for posting.

[0-60motorsports]

I had the same issue but it popped up out of the blue a year or so back. the car had running great for years. I changed the usual things you mention above (I am SMG). In the end my tech asked me to bring him my spare CSL converted DME and after installing that the issue is gone. Probably something wrong with the hardware on my HP DME. Will have to send it in to be checked.

Hopefully once you have adjusted your tune this issue will go away for you. I did try adjusting the tune and it didnt work.