GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV


  VW GTI Forum / VW Rabbit Forum / VW R32 Forum / VW Golf Forum - Golfmkv.com


 
Register
MYGOLF garage
Timeslips
Search
Members List
Search Today's Posts Mark Forums Read



Go Back   VW GTI Forum / VW Rabbit Forum / VW R32 Forum / VW Golf Forum - Golfmkv.com > Main Topics > GTI / Rabbit / Golf MkV General Discussions



Reply
 
Thread Tools
Old 07-13-2019, 06:28 AM   #1
Jremey
Passed Driver's Ed
 
Drives: 2009 gti
Join Date: Jan 2019
Location: Washington State
Posts: 13
Daily driver mk5 no boost

So a day or two ago I noticed I wasn't getting any boost. I could put the peddle to the floor and my boost guage runs flat at 0 and I used to peak around 15 psi. It feels and runs just like it did when I would get heat soaked. This was completely unexpected considering I just installed the Forge Twintercooler. I've been doing a bit of research and one of the more common things I'm finding is either the DV or the n75. The diverter valve is less than a year old, upgraded piston version. I'm also running a unitronic k04 with stage 2+ software and (this may sound dumb) I'm not sure if it has an n75 only because I don't remember seeing it when I installed the turbo, but I assume it has to have one and I'm sure I was probably staring right at it. I did have a small coolant leak which coincided with the IC install that I'm assuming occurred because the coolant hose got pulled away from the pump a bit while trying to maneuver the cooling stack to install the IC hoses. So I was thinking maybe I was getting heat soaked from engine temps rising from being low on coolant. However I'm not leaking coolant anymore and I'm full on fluid but I'm still not getting boost. I don't have vagcom to look at readings and for now I'm planning on taking it to a VW tuner shop after the weekend but really wanna try to figure this out before having to fork over my cc for shop diag. Any ideas out there?
Jremey is offline   Reply With Quote
Old 07-13-2019, 11:37 AM   #2
Perpetuus
Data Encryption
 
Perpetuus's Avatar
 
Drives: 07 GTI MK5 6MT
Join Date: Sep 2006
Location: In my garage
Posts: 835
Quote:
Originally Posted by Jremey View Post
So a day or two ago I noticed I wasn't getting any boost. I could put the peddle to the floor and my boost guage runs flat at 0 and I used to peak around 15 psi. It feels and runs just like it did when I would get heat soaked. This was completely unexpected considering I just installed the Forge Twintercooler. I've been doing a bit of research and one of the more common things I'm finding is either the DV or the n75. The diverter valve is less than a year old, upgraded piston version. I'm also running a unitronic k04 with stage 2+ software and (this may sound dumb) I'm not sure if it has an n75 only because I don't remember seeing it when I installed the turbo, but I assume it has to have one and I'm sure I was probably staring right at it. I did have a small coolant leak which coincided with the IC install that I'm assuming occurred because the coolant hose got pulled away from the pump a bit while trying to maneuver the cooling stack to install the IC hoses. So I was thinking maybe I was getting heat soaked from engine temps rising from being low on coolant. However I'm not leaking coolant anymore and I'm full on fluid but I'm still not getting boost. I don't have vagcom to look at readings and for now I'm planning on taking it to a VW tuner shop after the weekend but really wanna try to figure this out before having to fork over my cc for shop diag. Any ideas out there?
Check for a boost leak first. Also check that all your connectors are plugged in snug, particularly the ones that you would have touched or come close to during the Twintercooler install

But yes, N75 exists even on a K04.

I had a Twintercooler before and cannot recommend it especially if you are on a K03. Even with no boost leak, the extra pressure loss from the Twintercooler (an EXTRA intercooler) creates a very annoying lag in throttle response. I sold it the next day.
__________________
Íhlins | H2 Sport | Wagner Tuning | APR | AWE | VF Engineering | O.Z. | Wavetrac | VW Racing | H&R | Unitronic 2+ | DLI Teknik
Perpetuus is offline   Reply With Quote
Old 07-13-2019, 12:56 PM   #3
Jremey
Passed Driver's Ed
 
Drives: 2009 gti
Join Date: Jan 2019
Location: Washington State
Posts: 13
Quote:
Originally Posted by Perpetuus View Post
Check for a boost leak first. Also check that all your connectors are plugged in snug, particularly the ones that you would have touched or come close to during the Twintercooler install
The new connections was actually the first thing I thought of and those are good. The coupler I was given for the driver side originally was not a good fit. The hose kept popping off. The locking tabs were too wide so I had to grind them down to get it to fit and it worked. The twintercooler solved the heat soak issue and I had been running it for a couple weeks. Last time I had leaks with the new IC I could hear the leaks, very distinct high pitch whistle, I don't hear that anymore but I can still check for leaks. I saw someone post a link for DIY leak down check (I think that's what they called it). Anyone got that link still?
Jremey is offline   Reply With Quote
Old 07-13-2019, 03:03 PM   #4
ROH ECHT
K04 PLAY
 
ROH ECHT's Avatar
 
Drives: 2007 mkv gti
Join Date: Dec 2010
Location: PDX OR
Posts: 3,521
Is there an Autozone nearby for a free code reading? Yours still have the oem PCV? Have you tested that by disconnecting the PCV tube at the intake manifold and blow into it...it should seal and not allow air to pass through the valve. Nothing has suddenly blocked the air inlet? MAF working or been tested? DV has been checked again? N75 tested to be at 25 ohm minimum? Does the N75 have cracks in its plastic body or the ports/nipples? All connections of boost plumbing sealed? Can you smoke test the intake to throttle body for leak detection? Runner flaps still move?,...you can grab the linkage and move it, it should return to the start position when let go. Is the WG actuator rod still connected? As you likely know, there can be many causes to the loss of all boost.

FMIC note; I don't have lag or anything annoying with the Forge FMTwinC...and mine, a K04, is paired with the S3 FMIC. My actual boost meets its target within 700 rpm in a data log beginning from 2k rpm.

Weird your K04 only boosts to 15 psi before. Were you the original installer of the K04 or did you buy the car with the K04 and tune?

You up North in WA? Or close to PDX?
__________________
K04 PLAYZOOMDIS!
GIAC K04&DSG files/AWE DV/Autotech HPFP/Torqbyte PM3/TTRS LPFP/S3 INJ's&fmic/RS4 fprv/FORGE fmtc,WG act.&TB HOSE/Techtonics TB/Custom Turbo Outlet/BSH Mounts/NEUS. P-FLO&throttle pipe/13.2"BBK/W.A.L.K./H&R SS/H&R F&R-ARB's/Bilstein B8 Dampers My Dragtime link-GIAC tune2007 Volkswagen GTI : 12.823 @ 112.050 MPH

Last edited by ROH ECHT; 07-13-2019 at 03:17 PM.
ROH ECHT is offline   Reply With Quote
Old 07-13-2019, 08:19 PM   #5
Jremey
Passed Driver's Ed
 
Drives: 2009 gti
Join Date: Jan 2019
Location: Washington State
Posts: 13
Quote:
Originally Posted by ROH ECHT View Post
Is there an Autozone nearby for a free code reading? Yours still have the oem PCV? Have you tested that by disconnecting the PCV tube at the intake manifold and blow into it...it should seal and not allow air to pass through the valve. Nothing has suddenly blocked the air inlet? MAF working or been tested? DV has been checked again? N75 tested to be at 25 ohm minimum? Does the N75 have cracks in its plastic body or the ports/nipples? All connections of boost plumbing sealed? Can you smoke test the intake to throttle body for leak detection? Runner flaps still move?,...you can grab the linkage and move it, it should return to the start position when let go. Is the WG actuator rod still connected? As you likely know, there can be many causes to the loss of all boost.

FMIC note; I don't have lag or anything annoying with the Forge FMTwinC...and mine, a K04, is paired with the S3 FMIC. My actual boost meets its target within 700 rpm in a data log beginning from 2k rpm.

Weird your K04 only boosts to 15 psi before. Were you the original installer of the K04 or did you buy the car with the K04 and tune?

You up North in WA? Or close to PDX?
So per company policy I can neither confirm nor deny that I'm a store manager for AZ lol that being said I'll attach my code printout. I checked the pcv and I felt the check ball move to close when I blew in the hose so all good there. I'll have to check the runner actuator later after the engine cooks off. I am the k04 installer and as far as the 15ish psi goes, I had the exhaust and turbo inlet and outlet pipes ported and polished so I assumed I would get less boost than most since this should allow the turbo to work less for the same results. It really seems like it's something electronic. When I get on the gas it feels like it's requesting boost but not getting it, and it seems as though my gauge is reflecting this because it will spike around 3 psi then it'll fall flat at 0. The IC hoses and connections are solid. I also have the Forge Twintake and it won't make that flutter sound when I have IC leaks. I am in the PNW, I work in Lakewood and live in the Lacey/Olympia area.
My picture is taking forever to upload so here are my codes:
p0171 system too lean (bank1) populated twice
P0507 idle air control system rpm higher than expected
P2279 intake air system lean populated twice
P0243 turbo/supercharger wastegate solenoid A populated twice
P0101 mass or volume air flow circuit range/performance
I assume some of these are due to some of the mods but not sure.
Jremey is offline   Reply With Quote
Old 07-13-2019, 09:34 PM   #6
Jremey
Passed Driver's Ed
 
Drives: 2009 gti
Join Date: Jan 2019
Location: Washington State
Posts: 13
Quick question, if it is the n75, can I get an oem replacement or do I need to get one from a k04 say an a4 or something similar.
Jremey is offline   Reply With Quote
Old 07-14-2019, 09:09 AM   #7
Perpetuus
Data Encryption
 
Perpetuus's Avatar
 
Drives: 07 GTI MK5 6MT
Join Date: Sep 2006
Location: In my garage
Posts: 835
Quote:
Originally Posted by Jremey View Post
Quick question, if it is the n75, can I get an oem replacement or do I need to get one from a k04 say an a4 or something similar.
You're looking for an OEM replacement. Just make sure to pick the latest revision of the part. Some store like DAP should be able to help you out.
__________________
Íhlins | H2 Sport | Wagner Tuning | APR | AWE | VF Engineering | O.Z. | Wavetrac | VW Racing | H&R | Unitronic 2+ | DLI Teknik
Perpetuus is offline   Reply With Quote
Old 07-15-2019, 01:58 AM   #8
Jremey
Passed Driver's Ed
 
Drives: 2009 gti
Join Date: Jan 2019
Location: Washington State
Posts: 13
*Update*
I check the manifold runner actuator, it does return after I manually move it. I took out the MAF and cleaned it and had the battery disconnected on the off chance that doing so would reset the computer. Neither procedure worked. I'm looking into getting either vcds or obd11 pro, I'm leaning more towards pro since it's cheaper and it sounds like I can do more with it. With everything I'm reading and considering the codes I have, I'm really starting to think it's the n75 which is super frustrating since the turbo is brand new since December. That being said, tomorrow I'm gonna see if unitronics has any warranty on their products because for an n75 to go bad within a year on a $2500 turbo kit is ridiculous so fingers crossed.
Jremey is offline   Reply With Quote
Old 07-16-2019, 11:25 PM   #9
Jremey
Passed Driver's Ed
 
Drives: 2009 gti
Join Date: Jan 2019
Location: Washington State
Posts: 13
So I think I've gotten it narrowed down. I've got a new wastegate solenoid ordered, will be here on Thursday. I'm trying to test my DV, under 12 volts it stays closed when I push the piston in. So it would be opened not allowing the system to pressurize and create boost. With reverse polarity, the piston is forced out, closing the system allowing boost to build. I haven't been able to find anything on testing these considering most tests are regarding if the diaphragm or seal is bad on the OE style and not the piston style. Does this sound right to anyone?
Jremey is offline   Reply With Quote
Old 07-18-2019, 05:58 PM   #10
Jremey
Passed Driver's Ed
 
Drives: 2009 gti
Join Date: Jan 2019
Location: Washington State
Posts: 13
Problem solved. It was the n75. $35 part from work, not even gonna worry about unitronic's warranty.
Jremey is offline   Reply With Quote
Old 07-19-2019, 09:48 AM   #11
MagicMK
Autocross Champion
 
Drives: 2008 GTI
Join Date: Jan 2016
Location: PA
Posts: 92
Quote:
Originally Posted by Jremey View Post
Problem solved. It was the n75. $35 part from work, not even gonna worry about unitronic's warranty.
What is a N75? Is it that turbo solenoid thingy?
MagicMK is offline   Reply With Quote
Old 07-19-2019, 01:05 PM   #12
GTI's
FIA GT Champion
 
Drives: 2008 GTI Z4Z4 P03 PIP
Join Date: Sep 2013
Location: MD
Posts: 1,056
Quote:
Originally Posted by MagicMK View Post
What is a N75? Is it that turbo solenoid thingy?
Good read https://www.golfmkv.com/forums/showp...39&postcount=1
GTI's is offline   Reply With Quote
Old 07-19-2019, 01:59 PM   #13
MagicMK
Autocross Champion
 
Drives: 2008 GTI
Join Date: Jan 2016
Location: PA
Posts: 92
Quote:
Originally Posted by GTI's View Post
So, essentially, it is the solenoid thingy. Here's a description from ECS that may be more useful for those skimming the topic:

Quote:
Product Details
The N75 valve is vital to the health of your turbocharged engine, it controls when and how far to open the wastegate to allow boost pressure to be released.

Diagnosing a broken wastegate frequency control valve can be difficult, but a common symptom is a lack of boost pressure with no boost leak present in the system.

Replace your faulty N75 valve and restore turbocharger performance.
Also, I see Pierburg, the same German manufacturer that made my OE Diverter Valve replacement, makes this part, as well. I found it on FCP Euro for less than $20. For less than $20 and after changing my PCV, breather tube, and DV... it seems like a good idea to replace this as well.

How long did it take you to install?
MagicMK is offline   Reply With Quote
Old 07-19-2019, 03:10 PM   #14
ROH ECHT
K04 PLAY
 
ROH ECHT's Avatar
 
Drives: 2007 mkv gti
Join Date: Dec 2010
Location: PDX OR
Posts: 3,521
Quote:
Originally Posted by Jremey View Post
Quick question, if it is the n75, can I get an oem replacement or do I need to get one from a k04 say an a4 or something similar.
It's the same part;
06F 906 283 F
__________________
K04 PLAYZOOMDIS!
GIAC K04&DSG files/AWE DV/Autotech HPFP/Torqbyte PM3/TTRS LPFP/S3 INJ's&fmic/RS4 fprv/FORGE fmtc,WG act.&TB HOSE/Techtonics TB/Custom Turbo Outlet/BSH Mounts/NEUS. P-FLO&throttle pipe/13.2"BBK/W.A.L.K./H&R SS/H&R F&R-ARB's/Bilstein B8 Dampers My Dragtime link-GIAC tune2007 Volkswagen GTI : 12.823 @ 112.050 MPH
ROH ECHT is offline   Reply With Quote
Old 07-19-2019, 03:11 PM   #15
ROH ECHT
K04 PLAY
 
ROH ECHT's Avatar
 
Drives: 2007 mkv gti
Join Date: Dec 2010
Location: PDX OR
Posts: 3,521
Quote:
Originally Posted by Jremey View Post
Problem solved. It was the n75. $35 part from work, not even gonna worry about unitronic's warranty.
That's funny ↑...I responded to the post I quoted above in post #14, before getting to your post including you fixed it. Anyhow, apologies...been vacant for a bit. Glad you got it solved. I'll try remembering to check in...keep a note of the codes, clear them, then see which if any return. But likely the N75 had something to do with other codes...some at least.
__________________
K04 PLAYZOOMDIS!
GIAC K04&DSG files/AWE DV/Autotech HPFP/Torqbyte PM3/TTRS LPFP/S3 INJ's&fmic/RS4 fprv/FORGE fmtc,WG act.&TB HOSE/Techtonics TB/Custom Turbo Outlet/BSH Mounts/NEUS. P-FLO&throttle pipe/13.2"BBK/W.A.L.K./H&R SS/H&R F&R-ARB's/Bilstein B8 Dampers My Dragtime link-GIAC tune2007 Volkswagen GTI : 12.823 @ 112.050 MPH

Last edited by ROH ECHT; 07-19-2019 at 09:47 PM.
ROH ECHT is offline   Reply With Quote
Old Yesterday, 01:59 AM   #16
Jremey
Passed Driver's Ed
 
Drives: 2009 gti
Join Date: Jan 2019
Location: Washington State
Posts: 13
Quote:
Originally Posted by MagicMK View Post
How long did it take you to install?
Well unitronic used crinkle band clamps to attach the vacuum hoses to the n75 (wastegate solenoid) so taking those off was a nightmare until I decided to just yank them off. It actually wasn't TOO difficult to get to, but it took around roughly 1.5 hours because of the clamps. I also have some extra plumbing to move that comes with uni's stage 2 kit.

Quote:
Originally Posted by ROH ECHT View Post
That's funny ↑...I responded to the post I quoted above in post #14, before getting to your post including you fixed it. Anyhow, apologies...been vacant for a bit. Glad you got it solved. I'll try remembering to check in...keep a note of the codes, clear them, then see which if any return. But likely the N75 had something to do with other codes...some at least.
Yah the air intake leak I'm assuming is from the boost gauge tap that runs off the manifold. I think the pcv is recognizing that some air is being siphoned off. The code for the maf I'm assuming is from the Forge Twintake. Though I'm not sure what's causing the lean trim code. Oddly enough I haven't checked the codes again. I'll do that tomorrow.
Jremey is offline   Reply With Quote
Old Yesterday, 10:34 PM   #17
ROH ECHT
K04 PLAY
 
ROH ECHT's Avatar
 
Drives: 2007 mkv gti
Join Date: Dec 2010
Location: PDX OR
Posts: 3,521
Quote:
Originally Posted by Jremey View Post
Yah the air intake leak I'm assuming is from the boost gauge tap that runs off the manifold. I think the pcv is recognizing that some air is being siphoned off. The code for the maf I'm assuming is from the Forge Twintake. Though I'm not sure what's causing the lean trim code. Oddly enough I haven't checked the codes again. I'll do that tomorrow.
Umm, the boost gauge won't siphon off air. It is simply another part of the pressurized system. The lean code P2279 is usually due to a leak. A leak from the MAF to the turbo, including the rear breather hose and tube to the turbo. I remember one finding a leak in the short rubber hose between the rear breather tube and rocker cover but underneath where it couldn't be seen.

Code P0171 is a lean condition causing an additive trim; and could also be related to the P2279 but could be a separate issue within the fueling bits. Could be a failed PCV(torn diaphragm or failed check valve/s). Vacuum system leaks. Could be an exhaust leak pre-B1S1 O2 or pre-cat O2 sensor.

Can you get the fuel trim data?
Can you smoke test it?
Can you reach the small hoses connected to the new N75? Do they spin or are they tight?
Can you test the PCV and inspect its large diaphragm?
Do a MAF test?

There's also some decent info here: https://www.youtube.com/watch?v=oWJihSkQUuE
__________________
K04 PLAYZOOMDIS!
GIAC K04&DSG files/AWE DV/Autotech HPFP/Torqbyte PM3/TTRS LPFP/S3 INJ's&fmic/RS4 fprv/FORGE fmtc,WG act.&TB HOSE/Techtonics TB/Custom Turbo Outlet/BSH Mounts/NEUS. P-FLO&throttle pipe/13.2"BBK/W.A.L.K./H&R SS/H&R F&R-ARB's/Bilstein B8 Dampers My Dragtime link-GIAC tune2007 Volkswagen GTI : 12.823 @ 112.050 MPH
ROH ECHT is offline   Reply With Quote
Reply

Thread Tools

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

Forum Jump


All times are GMT -4. The time now is 03:15 PM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.