Lock up clutch slipping?

[Motohead]

2012 Flex EB 149,000 miles Livernois stage 4+ 93 tune Mycalabrator "Dash DQ" tuner CAI and cat-less down pipes since 10,000 miles raced A LOT

For a wile now I have been having a shudder under light load part throttle 1500-2500 rpm I can feel it in all gears but its most noticeable in third. Their are no trouble codes. I have taken it to a local shop who suposibility test drove it with their scan tool and diagnosed as random misfires I have changed out the plugs and all 6 COPs with no effect. I have also returned the truck to stock with no effect. The truck runs great as usual under WOT the shutter is only under light load.I'm leaning toward the possibility of transmission/converter lock up issues. Too prove/disprove this theory what transmission PIDs could I log and is there a way to monitor misfires with the Livernois unit?

[glock-coma]

I hate to say it but others who have had similar issues  found it to be cracked piston rings. If you do a search with the word shutter it might be easy to find.

[Motohead]

I hate to say it but others who have had similar issues  found it to be cracked piston rings. If you do a search with the word shutter it might be easy to find.

I would think it would smoke with broken rings but ill do a serch

[glock-coma]

Maybe do a compression test to rule it out.  But the symptoms were the same.

[SHOdded]

You can read codes with the MyCal, no datalogging though, sorry.  For that, you are best off with an OBD II adapter and Forscan Lite (or Torque Pro, for which we have custom PIDs also).

Do you see RPMs flutter without throttle input?  That is usually a sign of torque converter issues.  Light throttle/part load shudder can also be caused by the PTU.  Have you checked/changed the trans/PTU/RDU fluids?  Are there any rattles at any point - startup, part throttle, full throttle?  Does the coolant look clean, and is the degas bottle clear of debris/slime?

Since the problem is in so many gears, I would verify both fuel pumps and fuel injectors.  So you have to monitor fuel pressures, lambda on both banks, etc.

The symptoms seem to clear up at WOT, which would possibly indicate O2 (air/fuel sensor) involvement.  I assume since you have catless DPs, the rear O2s are turned off. 

We have certainly seen at least one other Flex that had a cracked block, hope that is not the case here.

[sholxgt]

I am battling the shudder or stutter as well.  Mine is in a narrower range though.  Mostly between 1400 - 1500 rpm.

All of my data logs look clear, but it's annoying.  Only made on trip to the dealer so far and they were unable to replicate the symptom.  I can't get it to not stutter so I think my next dealer visit will be me taking the service manager for a drive myself. 

[AJP turbo]

I am battling the shudder or stutter as well.  Mine is in a narrower range though.  Mostly between 1400 - 1500 rpm.

All of my data logs look clear, but it's annoying.  Only made on trip to the dealer so far and they were unable to replicate the symptom.  I can't get it to not stutter so I think my next dealer visit will be me taking the service manager for a drive myself.

I was wondering how your car was doing

[SHOdded]

Any difference made if you take O/D off?

[ZSHO]

Have you checked your CAC intercooler for any signs of oil inside with your oil dipstick? and also check your PCV valve or oil seperator especially if original.  Z

[Motohead]

I have the Dash DAQ-XL from Drew Technologies early rebranding by Livernois as Mycalibrator  unit (From 2012) and it does logging its also a GPS

[sholxgt]

Thanks for asking all!

Been driving it on the stock tune this week to see if I can figure out what's going on with it.  I'm thinking about paying the dealership to do a compression test with the idea that, if it shows a problem, they can bury the paperwork.  If it come out fine, then I will have peace of mind and pay for the test.  I could do the test myself, but I need them to have the results as well.

Here's where it stands...
- CAC cleaned about 3,000 miles ago and showing clean still
- cleaned the IAT and MAP sensors
- new Motorcraft plugs installed, gapped at .030
- stutter is predominantly when in 6th gear at 1400-1500 rpm, but it does do it randomly in other gears
- it also sometimes hiccups/stutters at low speeds on deceleration (this one makes me think PTU)
- idle quality is poor.  I don't have a point of reference from other 3.5EB's, but my idle quality is better than performance cars I've owned, but no where near that of a factory Honda, Toyota, etc.  This is, however, also the only car I've ever owned with a 600 rpm set idle.  Didn't even know a car could idle this low. LOL
- car doesn't pull any codes, but I saw this on the engineering screen...



Do your cars idle like silk at 600 rpm?  Mine bounces between 600-650 like it's not happy idling that low.

[Motohead]

Have you checked your CAC intercooler for any signs of oil inside with your oil dipstick? and also check your PCV valve or oil seperator especially if original.  Z

Ill check this but again no smoke does anyone know the pids (If their are any)to monitor for misfires
also which pids would show torque converter clutch info

[Motohead]

Any difference made if you take O/D off?

nope

[sholxgt]

Moto, are you certain your stutter happens all the way up to 2500rpm?  I would think that would eliminate torque converter as a culprit since lock up is much lower.

With your mileage, I would definitely recommend a CAC check.

[Motohead]

Moto, are you certain your stutter happens all the way up to 2500rpm?  I would think that would eliminate torque converter as a culprit since lock up is much lower.

With your mileage, I would definitely recommend a CAC check.

Ill take it for another spin and recheck are their any specific Pids i can log while im at it
i had the piping off at the throttle body hose clamp yesterday just looking around my dipstick wasen't long enough to check from there where do you do the dipstick check at?