Ecoboost Performance Forum

Ecoboost Performance => Troubleshooting, Maintenance, TSB Articles => Troubleshooting => Topic started by: MKS Tom on August 19, 2019, 12:19:52 AM

Title: Rougher ride under lower RPMs and off throttle input
Post by: MKS Tom on August 19, 2019, 12:19:52 AM
What would cause a lower speed, especially off of throttle input to feel a little roughness to the ride? It's not a bent or wheel balance issue. It's not a stuck caliper. It's not a wheel bearing issue.

I had taken it to a tire shop to have them check this stuff out and road test it and put it up on a left. They felt it and suggested this could be a transmission issue with it downshifting. I don't know if I believe that, but it's not what I thought it could be based upon the characteristics (wheel issue). It's not tune related as it did it on both AJP and Ortiz. I had thought I clipped a wheel as the roads in PA are brutal and was going to confirm this but it's not what I thought.  It was minimal enough for me not to pay attention to it right away, but hindsight.  lol

I do have a warranty and if it is something expensive I have coverage. I did have the trans fluid flushed recently but it was doing it before I had that done, it's very minor and more so at low speed/off the pedal, so I didn't much attention to it, and was sure it was me clipping a wheel that I was getting conformation on before taking it to a local wheels shop for repair. 

I did return to stock and drive it and it seemed to mask it a bit but it is still there.  I'm calling my mechanic to take it in as soon as he can, but frankly it drives fine otherwise.  It's weird as there are no slips or wonky stuff other than a slightly rougher ride when I am around 1500 RPMS and it can seem to feel it more without throttle input. 

Output bearing?  Driveshaft?  PTU?  Something along those lines IMO. 
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: SHOdded on August 19, 2019, 12:34:24 AM
If you are thinking driveshaft, you would feel vibration in the floorboard.  Check the hanger bearings to see if there is play.  The driveshaft is disconnected/does not turn in P or N, but is engaged in all other gears.

Does the AWD have any problems engaging?  Is there anything other than initial wheel slip/hop while taking off at WOT from a stop?  Say 0-40 mph.

Other possible candidates are mounts - engine, trans, or torque.

P.S.:  Please add a signature to your profile so we can see what mods, if any, are on your vehicle :)
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: MKS Tom on August 19, 2019, 01:29:48 AM
It's weird, nothing off the line and in shifting in general except a little longer/harder 2nd to 3rd at times over the past few months that wasn't really noticeable.  It doesn't slip, jerk, have weird revs, etc.  It's just a weird roughness at lower speeds/RPM and I do seem to nice it more off throttle.  No issues with AWD as far as I can tell.  No CEL for anything. 

I followed your advice and add content as to what my car has until the wife allows me to spend more on it.  lol

Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: ZSHO on August 19, 2019, 07:16:31 AM
I would try to rule out your Spark plugs gapped @ 0.026 ! When did you install the plugs! New COP!

Mode 6 Data is probable to check for any underlying misfire-spark issues. Z
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: MKS Tom on August 19, 2019, 10:48:53 AM
Plugs were done 3 months ago. Problems started showing up maybe a month ago, maybe a little longer. The trans did something weird where it got stuck in 1st trying to use the paddles. I did get the fluid changed. Who knows.
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: SHOdded on August 19, 2019, 12:14:33 PM
Assuming the fluid is at the top of the hashmarks when checked, I would keep TSS/OSS sensors and solenoid body in mind as possible culprits.  Does not seem to happen as often with transmissions using LV fluid, but once in a while ...  Speaking of which try resetting not just the KAM but the transmission adaptives and see if it makes a difference.  If resetting the trans adaptives makes a difference, that points directly at the solenoid body as the culprit.

Definitely more likely to be engine related - maybe the MAP sensors or the IAT2 sensor or spark plugs etc.  So give the sensors a good cleaning with MAF Sensor Cleaner.  Good opportunity to see if oil is fouling them.  I would imagine a PCV issue would show up more on throttle than off, but still worth checking the intercooler for buildup.  If you have done the BOV delete, that is another place to check.  Also the hoses at the wastegate solenoid atop the intake manifold.

Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: MKS Tom on August 19, 2019, 02:26:56 PM
It's weird, nothing shows up in any kind of datalogs that would give any indication of an engine issue.  It's going in Thursday at least. 
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: 6500rpm on August 20, 2019, 12:07:35 PM
Issue with the coast side of one of the gear sets?
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: MKS Tom on August 20, 2019, 02:44:02 PM
Even stranger is going back to stock seems to get rid of most of it.  This isn't a fault of the tuner as it does it on both of mine thought AJP and Ortiz.  Something with the added HP/torque is making something that is weak/failing cause this but it is much less stock. 
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: MKS Tom on August 22, 2019, 02:14:25 PM
Mechanic didn't find anything.  Made an appointment with the dealer for next week.  Why can't it just be a normal car and break? 
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: SHOdded on August 22, 2019, 06:32:04 PM
Hah!  Supercar with a nerd body.  Thats whatcha get!
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: MKS Tom on August 30, 2019, 02:46:37 AM
I await their decision. 

Dropped it at the dealer yesterday and they didn't get me in.  I hope they find something that I can use towards warranty.  Hate being stock.  lol
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: MKS Tom on August 31, 2019, 01:42:38 AM
PTU failing. 

Covered under warranty and it goes in next week.  :)
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: SHOdded on August 31, 2019, 08:25:01 AM
:o :D Well, at least there is an UPside 2 this!

https://www.ecoboostperformanceforum.com/index.php/topic,496.msg153502.html#msg153502 (https://www.ecoboostperformanceforum.com/index.php/topic,496.msg153502.html#msg153502)
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: MKS Tom on September 04, 2019, 03:27:31 PM
Dropped off and new PTU is going in tomorrow. 
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: SHOdded on September 04, 2019, 03:42:10 PM
Yeah!!!
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: MKS Tom on September 08, 2019, 01:04:04 AM
Got it back and it runs great!
Title: Re: Rougher ride under lower RPMs and off throttle input
Post by: avidmotion on September 13, 2019, 12:27:34 AM
When my ptu was going it made a weird whine sound varied by rpm....
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