Boost won't Exceed 7-8 PSI

SHOFox29

New Member
Joined
Jun 3, 2022
Messages
6
Reaction score
0
Location
Columbus
Hello SHO Forums! So I have a Stock 2010 Sho PP 106k Miles. My baby won't make above 7-8 at any RPM at any Speed. Many many things have been replaced all within the last 6 months by the dealer and myself.
By dealer:
Used engine with 85k miles(will include internal pics if I can)
All VVT Solenoids
All Plugs
All Ignition coils
Both Exhaust Flex pipes
Front turbo
All turbo oil lines
By me:
160⁰ Thermostat
Knock Sensor
Both Camshaft Position Sensors
MAP Sensor
Boost Solenoid
All Intake manifold gaskets
Valve cover gaskets
Many misc orings and seals related to intake manifold and valve cover
__Intake Valve cleaning job__

The car runs very well. No misfire, no studder, feels powerful but its not all quite there. Ive inspected all charge pipes and the clamps are tight. BOVs are clean and diaphragm is not torn. Took off rear catalytic converter and the exhaust inpeller on the rear turbo looks good and little to no play, wastegate flap is sealed strong. Im moments away from putting on a new rear turbo but I want to make sure im not missing anything and wasting my money and time. Thanks so much for any help!
 

Attachments

  • 20220324_181323.jpg
    20220324_181323.jpg
    392.8 KB · Views: 30

SM105K

Streetlight Grand Prix Champ/ IG @fafomotorsports
Joined
May 3, 2018
Messages
6,075
Reaction score
7,462
Location
Arizona
Have you checked the charge piping for cracks? The rear charge piping has been know to come apart near the turbo. Have you checked the intercooler for leaks as well? What about the noisemaker? They are known to leak under boost.
 

Ecoboost_xsport

SHO Member
Joined
Mar 21, 2020
Messages
1,897
Reaction score
3,633
Location
Sacramento, CA
Stock turbos still? Stock wastegatr spring is about 3-4psi, but ATP turbos have a 7-8psi spring....

Or it could be the boost solenoid is going out as well.
 

SHOFox29

New Member
Joined
Jun 3, 2022
Messages
6
Reaction score
0
Location
Columbus
Have you checked the charge piping for cracks? The rear charge piping has been know to come apart near the turbo. Have you checked the intercooler for leaks as well? What about the noisemaker? They are known to leak under boost.
Yes, charge pipes are all good, I've removed them all and cleaned them well. At one point I took off the noisemaker and put a plug in place because I was worried about boost leaks through there and saw no difference so I put it back on.
Stock turbos still? Stock wastegatr spring is about 3-4psi, but ATP turbos have a 7-8psi spring....

Or it could be the boost solenoid is going out as well.
100% stock, brand new OEM boost solenoid as stated in OP. The wastegate was concern as I swear I could hear it clacking and open/closing quickly at high load but when I took the catalytic converter off, the waste gate flap was still firmly clamped and didn't seem like it would be leaking or loose.
 

doit221

New Member
Joined
Nov 12, 2016
Messages
11
Reaction score
7
Yes, charge pipes are all good, I've removed them all and cleaned them well. At one point I took off the noisemaker and put a plug in place because I was worried about boost leaks through there and saw no difference so I put it back on.

100% stock, brand new OEM boost solenoid as stated in OP. The wastegate was concern as I swear I could hear it clacking and open/closing quickly at high load but when I took the catalytic converter off, the waste gate flap was still firmly clamped and didn't seem like it would be leaking or loose.
What about the actual pipe from the throttle body to the intercooler where the noise maker mounts to? The plastic hose clamps on them are junk and sometimes the pipe itself can get loose. I ended up replacing mine with the noise maker delete.
 

bpd1151

Lurking Around
Joined
Feb 21, 2010
Messages
2,855
Reaction score
6,126
Location
SHOcago 'Burbs
I am confident it is the diaphragm on one, or both of the electric bov's.

Remove them (the entire bov) from the piping, then extract or pull on the center plunger gently and inspect the rubber portion (should be orange in color, but could be another).

If you notice even the slightest of a tear, that'll be your culprit.

The only other issue I could think of (which that model year was prone to) the dreaded chafing of the knock sensor wires / wire loom.

Report back your findings and good luck.
 

SM105K

Streetlight Grand Prix Champ/ IG @fafomotorsports
Joined
May 3, 2018
Messages
6,075
Reaction score
7,462
Location
Arizona
What are the stock boost levels?
 

SHOFox29

New Member
Joined
Jun 3, 2022
Messages
6
Reaction score
0
Location
Columbus
I am confident it is the diaphragm on one, or both of the electric bov's.

Remove them (the entire bov) from the piping, then extract or pull on the center plunger gently and inspect the rubber portion (should be orange in color, but could be another).

If you notice even the slightest of a tear, that'll be your culprit.

The only other issue I could think of (which that model year was prone to) the dreaded chafing of the knock sensor wires / wire loom.

Report back your findings and good luck.
As a long time lurker, im happy to have your help =) I've inspected them before and thought it looked fine but perhaps im mistaken? Ive already replace the knock sensor, it was in fact chaffed.
 

Attachments

  • 20220603_171117.jpg
    20220603_171117.jpg
    156.8 KB · Views: 24
  • 20220603_171117.jpg
    20220603_171117.jpg
    156.8 KB · Views: 24
  • 20220324_144323.jpg
    20220324_144323.jpg
    349.7 KB · Views: 24

SHOFox29

New Member
Joined
Jun 3, 2022
Messages
6
Reaction score
0
Location
Columbus
I just took off and inspected the other one too, they both look fine and identical.
 

jasong_10

SHO Member
Joined
Oct 2, 2021
Messages
293
Reaction score
166
Location
Croghan, NY
You mentioned changing the MAP sensor, which one did you replace? There are (2) indentical looking sensors, (1) on the intake, and one on the intake tube near the noisemaker.
 

Forum statistics

Threads
104,012
Messages
1,147,735
Members
13,752
Latest member
Insidejobrobsho13

Members online

Top