Shudder on acceleration issue

[Flexthis2011EB]

Hello everyone. So i have a 2011 ford flex ecoboost with 110k miles with 50k engine. Recently i have had an issue where when i step on the throttle normal the car will start to shudder and shake like its misfiring yet i dont get a flashing MIL light like it would if it were misfiring. I read alot about some problem with acummulation of moisture and oil in the intercooler and a temp fix was to make a small drain hole to release the fluid built up in there. Such a small hole that it is undetectable and boost is not affected. It seemed like shutter went away at first but then came back. Its more noticeable going uphill but mostly always shudders at 40mph. Ive changed all spark plugs, cleaned all sensors, and tested all coils which were fine. I checked all fuel injectors and replaced one bad one and cleaned the rest. I have a check engine light on for catalyst bank 2 below threshold along with code for o2 sensor 1 bank 2. I was thinking a clogged cat. I know my o2 sensors are fibe because i monitered them on live data and they were working as they should. My o2 sensor 2 at bank 2 does fluctuate more than it should when watching on live data indicating gases may be passing straight through the cat, but a bad or clogged cat would generally make your car lose power quite noticeably. My flex, when the shutter is not happening is still a little rocket. It will zoom off, shudder, get through the shudders, and zoom of again and be fine until i stop and go again. Not really indicative of a bad cat. Im at a dead end. Anyone had this problem or know what it could be?? Im a very good mechanic but right now im stumped!!

[SHOdded]

Been reading more issues with the torque converter but there is a TSB 10-22-04 for the PTU being the cause of the shudder also.  So I'd look into the PTU first, as it's easiest.  Drain the fluid, if it's muck and/or contains debris, that may be the answer right there.

If you are amenable to using Forscan on a smartphone/tablet, there are various transmission related PIDs you can monitor to see if the torque converter is involved.  Since you are looking at O2 values, I assume you are monitoring already in some manner.

The Bank2 Sensor 1 is a popular one to go bad.  Which bank was the bad injector on?  Do you have any logs showing how your fuel system/o2 sensors are behaving?  If you would need to grab some, would add the trans PIDs to the list.  AJP will likely have suggestions exactly which PIDs, I grab any that indicate Torque Converter.

[BiGMaC]

You could also clean the sensors to see if that stops the fluctuation you see.

I have seen the drilling of a hole in the IC discussed. IMHO it is still a boost leak and if your boost seems unaffected then you have to be adding work for the turbos. I'd recommend installing a petcock in the hole and draining intermittently.

[FoMoCoSHO]

How did you check and clean your injectors?

[gearheadred]

My friend recently had the same issue on his Dodge - replaced plugs, coils, and even had the tranny rebuilt. Exact problem persisted. Then someone suggested he use better quality gas and that cured the problem 100%. No issues for 3+ months now. Just a thought...

[gearheadred]

One more thing - codes showed he had a chronic misfire on cylinder 5, causing the violent stumbling under acceleration. Misfire did not change cylinders when coils were swapped. This injector was also replaced, and that didn't fix the issue for long. It was only the change to better fuel that resolved it.

[Flexthis2011EB]

How did you check and clean your injectors?

Checked them visually by removing them and cleaned by the plunger and battery method

[Flexthis2011EB]

Been reading more issues with the torque converter but there is a TSB 10-22-04 for the PTU being the cause of the shudder also.  So I'd look into the PTU first, as it's easiest.  Drain the fluid, if it's muck and/or contains debris, that may be the answer right there.

If you are amenable to using Forscan on a smartphone/tablet, there are various transmission related PIDs you can monitor to see if the torque converter is involved.  Since you are looking at O2 values, I assume you are monitoring already in some manner.

The Bank2 Sensor 1 is a popular one to go bad.  Which bank was the bad injector on?  Do you have any logs showing how your fuel system/o2 sensors are behaving?  If you would need to grab some, would add the trans PIDs to the list.  AJP will likely have suggestions exactly which PIDs, I grab any that indicate Torque Converter.

Honestly it feels more like a problem thats trans. related. So i will most def look into this. As far as my pids, the ltft were fine, but the o2s downstream are questionable. Sensors 1 in both banks are fluctiation appropriately but i can only see them read on my scanner in mA so i dont know how to convert to volts as i know they are supposed to read between .1-.9v but they generall fluctuate between -.030-.030mA. The rear sensors are measured in volts though and bank 2 sensor 2 is flucuating alot which usually points at bad cat but all other tests (looking for signs of overheating metal, vacuum test check back pressure) checked out plus i know a plugged cat will cause serious power reduction which mine does but only for breif moments. I want to check more into this convertor feal, so ill need to know which pids to moniter.

One more thing - codes showed he had a chronic misfire on cylinder 5, causing the violent stumbling under acceleration. Misfire did not change cylinders when coils were swapped. This injector was also replaced, and that didn't fix the issue for long. It was only the change to better fuel that resolved it.

I will also try a dose of 91 octane to see if that helps.

You could also clean the sensors to see if that stops the fluctuation you see.

I have seen the drilling of a hole in the IC discussed. IMHO it is still a boost leak and if your boost seems unaffected then you have to be adding work for the turbos. I'd recommend installing a petcock in the hole and draining intermittently.

I have cleaned all sensors required and thank you on the petcock idea. I will be crafting that up tomorrow :-)

[AJP turbo]

Have you had a dealer update the ECU? And also the primary 02's are 0-5V not whatever you or that other
flub posted

Not sure how you could check or even clean an ecoboost injector.

And I would replace both primary 02 sensors being that you have 110k and the car is getting old.

And I really think you need an ECU update...The main fix for the misfiring on the 3.5 eco is the "allowable wheel torque error" in the tune.

The fuel is not the problem unless you had absurdly bad gas....The car is perfectly fine on 87 octane.

[SHOdded]

Correct, the front or primary O2s are wideband, so they should show between 0 and 5 volts.  The rears are narrowband, so should show between 0 & 1 volts.

87 fuel doesn't really leave much room for error on these engines, hopefully your Flex is stock tune.  Definitely put a plug in that hole you put into the intercooler, then drain periodically.  Check the turbos themselves for pooling oil (probably seal leak) and carbon buildup.

Hopefully running 91 a few tankfuls is all you need to fix this issue, make sure you use top tier stations only, Chevron if you have them available.  Adding BG 44K would also help if the cats are still kicking around.
http://youtu.be/uSn_eIPdhOY?t=1m30s

[pmezo33]

Sounds exactly like the symptoms my car had when my torque converter started to fail recently.

[Flexthis2011EB]

Correct, the front or primary O2s are wideband, so they should show between 0 and 5 volts.  The rears are narrowband, so should show between 0 & 1 volts.

87 fuel doesn't really leave much room for error on these engines, hopefully your Flex is stock tune.  Definitely put a plug in that hole you put into the intercooler, then drain periodically.  Check the turbos themselves for pooling oil (probably seal leak) and carbon buildup.

Hopefully running 91 a few tankfuls is all you need to fix this issue, make sure you use top tier stations only, Chevron if you have them available.  Adding BG 44K would also help if the cats are still kicking around.
http://youtu.be/uSn_eIPdhOY?t=1m30s

I will look into the pooling inside the turbo. And most def be putting in a drain plug

.

Sounds exactly like the symptoms my car had when my torque converter started to fail recently.

How much did u spend on a new t convert?

[pmezo33]

How much did u spend on a new t convert?

I ended up doing a full rebuild along with the new torque converter.  When a torque converter goes, it can send metal shavings through all the transmission lines and through the transmission, so doing the rebuild seems to be the safest route to make sure nothing else goes wrong down the road due to contamination.  Ended up getting a pretty decent deal at $1800 for the full job with a year warranty.  I got estimates up to $4k for the job depending on where i went though.  Didn't even bother with the dealer.

Have you seen my thread?  You might want to take a look at it.  I ended up figuring out that it was the torque converter by trying a transmission additive and it immediately worked.  This was obviously after trying quite a few other things first and was kind of a last resort since nothing was helping. It worked great, but it didn't last more than a few thousand miles, so i ended up getting the new torque converter and the rebuild done.  Car runs like it's brand new again - shuddering is gone. 

http://www.ecoboostperformanceforum.com/index.php/topic,6022.0.html

[Flexthis2011EB]

Heres a video i took of the shaking/shuddering/jerking i experience. https://youtu.be/-y2VIYXRSag
It happens at the beginning of video and at around 43 sec mark of video. Usually around 35-45mph and as u see theres no rpm flucuation.

[SHOdded]

Hmm, behaves like your Flex has 1 or more plugged cats.  Might be 1 is plugged, other not, causing uneven power delivery ...