Turbo 'flutter' during low rpm / high gear acceleration...

Okay, so I just registered specifically for this thread.  Hello!

I am having the same issue with my 2015 SHO that the OP describes.  And I mean EXACTLY.  Low RPM flutter/surge on the highway as you attempt to gently increase speed up an incline.  If the car is able to gear down, the problem stops completely.  It is faint enough that the dealer obviously can't "replicate," and I'm afraid I was not surprised.

Was there ever a resolution?  Or did those here decide it was a natural characteristic of the EB?

I checked all the hoses on the top of the engine very carefully -- all are soft, pliable, and properly connected.  I also cleaned out the CAC, and I'll be putting new plugs in next week.

I am disturbed that a tune only made the matter worse, as I was hoping a tune would be the solution.  I know Torrie at Unleashed told me he could make the car downshift faster from 6th to 5th, so maybe that's the answer . . . .
 
John Miller said:
Okay, so I just registered specifically for this thread.  Hello!

I am having the same issue with my 2015 SHO that the OP describes.  And I mean EXACTLY.  Low RPM flutter/surge on the highway as you attempt to gently increase speed up an incline.  If the car is able to gear down, the problem stops completely.  It is faint enough that the dealer obviously can't "replicate," and I'm afraid I was not surprised.

Was there ever a resolution?  Or did those here decide it was a natural characteristic of the EB?

I checked all the hoses on the top of the engine very carefully -- all are soft, pliable, and properly connected.  I also cleaned out the CAC, and I'll be putting new plugs in next week.

I am disturbed that a tune only made the matter worse, as I was hoping a tune would be the solution.  I know Torrie at Unleashed told me he could make the car downshift faster from 6th to 5th, so maybe that's the answer . . . .
Click to expand...
Welcome aboard John,please follow this link and introduce yourself and we will proceed from there,thanks.  Z  :)    http://www.ecoboostperformanceforum.com/index.php/board,14.0.html
 
Its starting to sound more interesting....they way you are making it sound it sounds like a hole in a tune perhaps

Be nice if someone could capture a data log....i know in higher gears like 5th and 6th the tq converter commands less slip at lower rpms and i dont think the car likes it....i used to feel a slight bucking and quite knocking that drive me nuts....didnt see rpm surging but i wasnt looking...i added a little slip below 1500 rpm and it seems fine now
 
I was actually leaning towards it being a trans/converter issue at one point. But the more I experience it, the less I think that.

The only thing that makes me think it's not a tune issue is the reporting by others that it is worse with the tune than with stock.

I haven't got around to buying a tuner yet, as I didn't want to start down the road of the added expense and warranty concerns with a aftermarket tune until I was sure this issue was not a mechanical problem. So, I can't datalog yet. Maybe it is in my best interest to go ahead and buy the tuner and get the data logs done, and then see what I have before I start on the road of an aftermarket tune.


Sent from my iPhone using Tapatalk
 
John Miller said:
I was actually leaning towards it being a trans/converter issue at one point. But the more I experience it, the less I think that.

The only thing that makes me think it's not a tune issue is the reporting by others that it is worse with the tune than with stock.

I haven't got around to buying a tuner yet, as I didn't want to start down the road of the added expense and warranty concerns with a aftermarket tune until I was sure this issue was not a mechanical problem. So, I can't datalog yet. Maybe it is in my best interest to go ahead and buy the tuner and get the data logs done, and then see what I have before I start on the road of an aftermarket tune.


Sent from my iPhone using Tapatalk
Click to expand...
John how many miles on your SHO? Do you have over 15k on her?  Z
 
John Miller said:
Yes, I have a 23,000 miles on it and counting.


Sent from my iPhone using Tapatalk
Click to expand...
I would simply check to see if a strategy update is in order by your dealer.  Z
 
I have had something simular when I had both sides VTA.  But it was only up in the mountains under cruise control. I went back to 1 VTA and that seemed to help
 
Vent to Atmosphere for the blowoff valves.  HowTo video:
https://youtu.be/kF7ix_ZxcCM

Generally, only the front is done, as the rear BOV is harder to access.
 
Gotcha.

If both are vented, and closing one helped but didn't solve, wouldn't that again point to it being a boost issue as the original cause of the flutter?


Sent from my iPhone using Tapatalk
 
Some type of issue related to boost, yes.  But where exactly has been hard to locate, maybe in the feedback circuits, assuming boost is even built at all under the given conditions.  And your SHO is not currently VTA'd anyway, right, John?
 
From my experience it seems to be from a combination of sources. Trying to maintain speed up a climb the computer calls for more boost.  Then the computer may begin to detect knock or low speed pre ignition. So it dumps boost and the process starts again. But if I dropped the trans down a gear the problem went away. 

The car thinks it has enough power to meet the required load but then its just not working out. It needs to downshift but the programming doesn't call for it
 
Not VTA'd. Stock now, though I did just order a tuner to datalog and will look to tune once comfortable with the idea.

In the end, if I can get comfortable that this is not a mechanical problem that will get worse, having the trans kick down to 5th sooner (via a tune) might be a viable fix.

I drive 120 miles round trip each day, over mountains, and this flutter deal really hurts my enjoyment of a car I otherwise love.


Sent from my iPhone using Tapatalk
 
John Miller said:
Not VTA'd. Stock now, though I did just order a tuner to datalog and will look to tune once comfortable with the idea.

In the end, if I can get comfortable that this is not a mechanical problem that will get worse, having the trans kick down to 5th sooner (via a tune) might be a viable fix.

I drive 120 miles round trip each day, over mountains, and this flutter deal really hurts my enjoyment of a car I otherwise love.


Sent from my iPhone using Tapatalk
Click to expand...
Whats your elevation?  Z
 
Hello all,

2014 explorer sport.  Have the same issue as the OP.  Present since day 1.  I suspect all 3.5 ecoboosts do it.  If anyone wants to find out, vent the bypass valves to atmosphere, find a long slight hill on a highway and keep the vehicle at 65mph without letting car downshift. You will here the bypass valves dump boost every second or so.  It is not the wastegates.

For me, it was present at stock, worse with the addition of my downpipes, and worse with diablosport tune.  Downshift with a little gas or the paddles and it all goes away. It's annoying and I still am trying to find out if any tuner can tune it out.  I think its too much boost under partial throttle and little bit of load.
 
If it was too much boost the wastegates would open more and wastegate duty cycle would decrese.....i think its something else
 
Tori at unleashed tuning says that he can make the car gear down to fifth sooner. Seems to me that is the answer. In the next couple days, I am going to data log the event on the stock tune. It is my hope that I can send that to Tori, and he could see the event, and see where it occurs based on throttle position, boost, RPMs, etc. From there, I'm hoping that he could make it downshift immediately preceding the event.


Sent from my iPhone using Tapatalk
 
You must log in or register to reply here.

Similar threads

C
my 2017 SHO w/PP
2 3 4
Replies
65
Views
27K
SHOdded
S
1
Pcv issue or turbo seals?
Replies
0
Views
4K
13shonuff
1
S
Water pump, timing chain and unsolicited info
Replies
1
Views
8K
SHOme
S
L
2014 SHO Surging / Loss of Power
Replies
17
Views
15K
LipschitzWrath
L
U
2010 SHO turbo hose blowing off
Replies
0
Views
2K
usmcpi
U
Back
Top