Fluttering RPMs

pmezo33

New member
Last couple days I've noticed when accelerating that my car is fluttering a little.  It's only under light acceleration and the RPMs kind of flutter around and not smooth.  Same thing happens if I'm cruising and lightly give gas.  RPMs don't hold steady and kind of just very lightly fluctuate up and down.  I see it on the gauge and I feel it in the car. 

This is a good example of what I mean.  This is not my car, but a good example of what my rpm guage looks like.  Go to the 14 second mark in the video.

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

No CEL.  Plugs have about 30k miles on them.  Car has about 90k miles.  Any ideas?  This is a 2010 MKS. 
 
Are you monitoring to see if any boost is showing when the flutters happen?  Could be a sticking wastegate, could be a torque converter (early stages).

EDIT:  check carefully for exhaust leaks, particularly if you have aftermarket equipment installed.  Gaskets & clearance ...
 
I'll hook up the torque pro and monitor boost.  See if anything is going on there.

I really don't want this to be a transmission problem...

Definitely not hearing any exhaust leaks.  Nothing is aftermarket on this car.  Completely stock.
 
Wastegate hoses all look good and connected.  I did the plugs about 30k miles ago and changed all the boots at the same time.  They should all be good too.

If this were a torque converter issue... how exactly is this diagnosed?  Never had an issue with one before.
 
All the hoses atop the intake manifold also confirmed good & tight?  May look tight, but could be actually coming loose.  Try cleaning the MAP sensors see if that helps any.

30K on plugs should be ok if completely stock.

Too early to diagnose the TC, usually there's some shuddering accompanying it, which does not seem to be the case here?
 
Well, I don't think this is it, but check the knock sensor wiring for chafing, ESP since yours is a 2010.  Hopefully as simple as that ...
 
Wires look good.  Just double checked all the hoses and everything looks good and connected.  It's pretty clean in there.

Cleaned both map sensors about 10 or 20k miles ago.  Those have to be good too.
 
Curious if you have this at all times?  I have something like this when I first pull out of my drive in the morning but after that never again and it doesn't happen every day.
 
jpeckinp said:
Curious if you have this at all times?  I have something like this when I first pull out of my drive in the morning but after that never again and it doesn't happen every day.

Started two days ago.  This is a new symptom.  And yes, it's not just right when i start the car.  The car can be on for hours and it will do it. 
 
I read somewhere that TC problems can start with a sticking valve body.  You have already changed out the trans fluid, right?  How long ago was that?
 
SHOdded said:
I read somewhere that TC problems can start with a sticking valve body.  You have already changed out the trans fluid, right?  How long ago was that?

Did a 1x drain and fill about 20k or 30k miles ago, so some fluid was changed, but not all.  Thinking about doing a 3x drain and fill tomorrow.  Hoping that helps.

Thinking about trying this product along with the trans fluid change.  I'm always weary of snake oil products, but this one seems to have pretty good reviews.

http://www.amazon.com/gp/product/B0007ZAJRM/ref=s9_simh_gw_g263_i1_r?ie=UTF8&fpl=fresh&pf_rd_m=ATVPDKIKX0DER&pf_rd_s=desktop-1&pf_rd_r=0JYXZTSWMCBJSBHDBY4K&pf_rd_t=36701&pf_rd_p=2437869742&pf_rd_i=desktop
 
jpeckinp said:
I'm hoping mine is just a cold plug problem. I'm going to have them changed soon. Have 56k on a '13 SHO.
Jpeckinp ifhttp://www.ecoboostperformanceforum.com/index.php/board,14.0.html you would please introduce yourself simply by following this link,thanks.  Z    :)
 
Couldn't resist putting this off until tomorrow, so down in my garage doing my 3x drain and fill. Checked the trans oil level and it was low, but it was cold, so not exactly how sure how low.  Also chocolate milk in color which isn't good.  Not pink at all anymore.  Looks almost like motor oil.  Didn't smell burnt though.
 
Never changed the PCV valve.

I was on my second drain and fill and the shuddering is getting worse.  I'm almost afraid to drive it at this point and making it worse.  You can definitely feel it on slow accelerations and between the gears.  It's very noticeable at like 50 mph and then giving a little gas.  Feels like i'm going over those bumps on the side of the highway to alert you when drifting.  This isn't good.
 
Back
Top