P0234 Overboost/ No Power - Page 2 - 6SpeedOnline - Porsche Forum and Luxury Car Resource

Notices
Bentley From the original 3 Litre to the current Continental GT and Mulsanne

P0234 Overboost/ No Power

 
  #16  
Old 03-07-2019, 11:51 AM
Registered User
Join Date: Feb 2018
Location: Wisconsin
Age: 61
Posts: 205
Rep Power: 10
1eapplebaum is on a distinguished road
I'm not at the shop now. As I recall there's one 6 mm hex head screw with a 10 mm head that has to come out. Then you have to give it a good pull but be careful there's a wire to the mass air flow sensor. That cable can be tricky to disconnect since it has the typical Volkswagen quick connect. Go online look how to disconnect Volkswagen quick connects. There are different ideas. Anyway I have my way which I can elaborate on later if you need help.

Also disconnect the PCV connection at the intake manifold. Be gentle the plastic inside this tube is fragile and cracks. Then you have a vacuum leak. Should that tube crack there's a way to fix it but be gentle, nonetheless.
 
  #17  
Old 03-07-2019, 01:47 PM
Registered User
Thread Starter
Join Date: Mar 2019
Location: California
Age: 37
Posts: 11
Rep Power: 0
Max Vehicles is an unknown quantity at this point
The air box just needed a firm tug to come off. I can take more pics if necessary.









 
  #18  
Old 03-07-2019, 03:00 PM
Registered User
Join Date: Feb 2018
Location: Wisconsin
Age: 61
Posts: 205
Rep Power: 10
1eapplebaum is on a distinguished road
The turbo impeller looks good. Worthy onf inspecting the other one.

See if it's possible to get independent results from each turbo.

Through vcds, find a way to test the solenoids above the transmission that control the turbo wastegate vacuum.

There are two diaphragms on the turbo one is for the wastegate, the big one. The other is the little white plastic in the image with a small vacuum line, not sure what this does.

Internal diaphragm failure would cause overboost to happen.


The previous evaluations were not in vain they point towards deeper analysis. The situation highlights why it gets so expensive at a dealership. They are faced with the same problem and it gets very time-consuming.

From this standpoint even if pulling the engine took 2 hours which it doesn't, what's next? Hopefully someone out there has had a similar experience and can throw out a few thoughts.

The Assumption is the car other than this overboost condition

runs well and not symptomatic of main vacuum line leaks?

[Sorry I inserted the photo in the wrong place. Don't know how to move it so there it is].


Let's make this a group effort, and figure out what's ailing this car.
 

Last edited by 1eapplebaum; 03-07-2019 at 03:03 PM.
  #19  
Old 03-07-2019, 03:13 PM
Registered User
Join Date: Feb 2018
Location: Wisconsin
Age: 61
Posts: 205
Rep Power: 10
1eapplebaum is on a distinguished road
Originally Posted by 1eapplebaum View Post
The turbo impeller looks good. Worthy onf inspecting the other one.

See if it's possible to get independent results from each turbo.

Through vcds, find a way to test the solenoids above the transmission that control the turbo wastegate vacuum.

There are two diaphragms on the turbo one is for the wastegate, the big one. The other is the little white plastic in the image with a small vacuum line, not sure what this does.

Internal diaphragm failure would cause overboost to happen.


The previous evaluations were not in vain they point towards deeper analysis. The situation highlights why it gets so expensive at a dealership. They are faced with the same problem and it gets very time-consuming.

From this standpoint even if pulling the engine took 2 hours which it doesn't, what's next? Hopefully someone out there has had a similar experience and can throw out a few thoughts.

The Assumption is the car other than this overboost condition

runs well and not symptomatic of main vacuum line leaks?

[Sorry I inserted the photo in the wrong place. Don't know how to move it so there it is].


Let's make this a group effort, and figure out what's ailing this car.
Being a 2007 there's a possibility the wastegate solenoid I'm referring to is behind the engine under the steering rack. Above I mentioned on top of the transmission. If not mistaken 2007 was a transition year for that design.
 
  #20  
Old 03-07-2019, 03:34 PM
Registered User
Thread Starter
Join Date: Mar 2019
Location: California
Age: 37
Posts: 11
Rep Power: 0
Max Vehicles is an unknown quantity at this point
I really appreciate your help. I am going to try a few more things and then probably just try to find a good indy in Sacramento and pay them a diagnostic fee. But, like you said, finding someone to diagnose this correctly without spending many hours is easier said than done. I will look at the other impeller. I have not smoke tested it, so a vacuum leak is possible. The reason I was assuming that the cause is not a severe vacuum leak is that my fuel trims look fine at idle and I have no other codes.

My only possible idea based on what we have found so far is that there is so much oil in the intercooler fins on the driver side that it might be creating a big enough restriction to cause this (but I really doubt that it is a big enough restriction to be the entire problem).

This is my plan: 1) Log the other turbo. The one I did is module 01 (which is the main ECU). I logged 115 while in that module to get the boost. I believe if I log 115 in module 31 (the other ECU) I will get boost for the other turbo. I do not know which is left or right, but I can probably figure that out.

2) Test in VCDS. I know I can test some of the solenoids and other components in VCDS, I am just not sure which ones or how. I did find instruction for some of these tests for Audi and VW, I will try those and try to figure out how to do more.

3) Indy. If it is not figured out by this point I will start trying to find a good Indy in Sacramento.
 
  #21  
Old 03-07-2019, 04:04 PM
Registered User
Join Date: Feb 2018
Location: Wisconsin
Age: 61
Posts: 205
Rep Power: 10
1eapplebaum is on a distinguished road
Save that thought on the oil in the intercooler.

Removing the engine compartment intercooler hose on the driver side and likewise the lower one which you just disconnected and reconnected. Use in well-ventilated area, chlorinated brake cleaner and air pressure from the top and blow that sucker out. Don't risk going through all this have Indie tell you have a clogged intercooler.

Still in the realm of cheap. Worth a try.
 
  #22  
Old 03-10-2019, 12:30 PM
Registered User
Thread Starter
Join Date: Mar 2019
Location: California
Age: 37
Posts: 11
Rep Power: 0
Max Vehicles is an unknown quantity at this point
I cleaned out the intercooler and put everything back together. Unfortunately, the only way to measure the boost on each side that I could figure out in VCDS would not allow me to log any other values simultaneously. A second gear pull with both sides boost values is posted below. The beginning looks a little strange because I was on a turn and there was a little traffic so I had to back off the throttle for a second. The data on the left is the same side from the previous data (I am guessing the driver side, but I am not sure). The data on the right (the side we have no seen before) looks better to my untrained eye. It looks to me like there is a blockage on the side we originally loged, but the other side might be ok. I will test some more things with VCDS tomorrow. I can log data for N75 boost controller and I think I will be able to test it and some other components.


 
  #23  
Old 03-11-2019, 08:27 AM
Registered User
Join Date: Feb 2018
Location: Wisconsin
Age: 61
Posts: 205
Rep Power: 10
1eapplebaum is on a distinguished road
Stick with it. You'll figure it out. Why pay someone 100 plus dollars an hour.

Been there done that.
 
  #24  
Old 03-13-2019, 04:54 PM
Registered User
Join Date: Feb 2018
Location: Wisconsin
Age: 61
Posts: 205
Rep Power: 10
1eapplebaum is on a distinguished road
Hope you solved the overboost condition.

Just occurred to me. There's two one-way valves one for each turbo behind the engine under the little plastic cover that pops off. They are round about the diameter of a quarter. These one-way valves are in line of the rubber vacuum line in back of the intake manifold. Should one of these go bad overboost / underboost can occur.
 

Last edited by 1eapplebaum; 03-13-2019 at 04:57 PM.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
spooltime
Cayenne Turbo
2
10-28-2018 12:39 PM
TURBO ELECTRO
996 Turbo / GT2
6
02-04-2009 07:01 PM
LSM
997 Turbo / GT2
7
09-21-2006 01:45 PM
MJC123
997 Turbo / GT2
8
06-24-2006 04:13 PM
BlackBear
997 Turbo / GT2
5
05-06-2006 11:20 AM


Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: P0234 Overboost/ No Power


Join 6SpeedOnline
Visit our Sponsors

Contact Us About Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

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.