Fluttering and boost issues on fresh LHU swap - Cobalt SS Network



2.0L LNF Performance Tech 260hp and 260 lb-ft of torque Turbocharged tuner version.
Technical Discussions ONLY!

Reply
 
 
 
Thread Tools Search this Thread
Old 05-14-2018, 11:42 AM   #1  
New Member
Thread Starter
 
Join Date: 09-01-17
Location: Quebec
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
Fluttering and boost issues on fresh LHU swap

Hi everyone! So I finished my LHU swap and I have some boosting problems. It still has the LNF hpt tune on it but I'm changing it next weekend so the car won't run until the new tune. Just to make sure what can cause my problems, if it's related to the bad tune or if it's physical mechanic pieces.

The car is fluttering af. Stock bpv. We tried with another one that was functional from another friend cobalt. Same result.

Car boosting at 6 psi max, we tried another map sensor gms1 like I have from another friend cobalt, car started to boost at 22 psi but still has fluttering. We put back mine, car was still boosting at 22 psi with my sensor but 9 hours later (this morning), it came back to 6 psi max.

Vacuum is at 20-21 so looks good.

So what can cause the fluttering and the non constant boost? Can it be tune related or purely mechanical?
Julien Scherer is offline   Reply With Quote
Old 05-15-2018, 03:06 PM   #2  
New Member
Thread Starter
 
Join Date: 09-01-17
Location: Quebec
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
Anyone?
Julien Scherer is offline   Reply With Quote
Old 05-16-2018, 07:20 AM   #3  
Super Moderator
Platinum Member
iTrader: (2)
 
Join Date: 07-14-08
Location: canada
Posts: 11,632
Thanked 96 Times in 86 Posts
Fluttering as in ur bpv is not opening?
tomj77 is offline   Reply With Quote
Old 05-16-2018, 09:49 AM   #4  
New Member
Thread Starter
 
Join Date: 09-01-17
Location: Quebec
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
yeah like a stututututu noise
Julien Scherer is offline   Reply With Quote
Old 05-16-2018, 10:09 AM   #5  
Premium Member
iTrader: (8)
 
07blackg5's Avatar
 
Join Date: 11-05-07
Location: Michigan
Posts: 4,929
Thanked 129 Times in 107 Posts
stustustu noises are only okay if following a brapbrapbrap
07blackg5 is offline   Reply With Quote
Old 05-16-2018, 10:48 AM   #6  
New Member
Thread Starter
 
Join Date: 09-01-17
Location: Quebec
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
Yeah but not in this case, it only does compressor surge and I don't know why. I don't want to drive the car and break something
Julien Scherer is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
LHU Swap LTBALTBMX 2.0L LNF Performance Tech 6 12-09-2017 02:35 PM
2009 cobalt ss sedan lhu swap asetech17 Complete Cars 12 11-10-2017 08:15 AM
Fluttering noise under load/boost AZCobaltss Problems/Service/Maintenance 3 10-29-2014 03:02 PM
Loud fluttering noise when i shift...5 psi boost pummy023 08-10 SS Turbocharged General Discussion 35 07-06-2013 01:35 AM
LHU/LNF swap? Ltguy 2.4L LE5 Performance Tech 6 08-07-2012 08:15 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 01:42 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.