MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: stacy2704 on February 21, 2017, 09:46:44 pm

Title: Dumping boost on throttle
Post by: stacy2704 on February 21, 2017, 09:46:44 pm

Hi guys, I seem to be having a possible boost issue. so when i floor it, it sounds like the recirc dumps and then a sort of puffing sound like a steam train. I always thought it felt a little flat but i put it down to being used to more poweras my last car was a mapped focus st. it was only since putting an induction kit on i noticed the noise. sadly i dont have vagcom so cant do a log i just wondered if anyone has had the same thing? i do have the management light on for incorect flow on the evap purge valve but im not sure how that could be related.
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi18.photobucket.com%2Falbums%2Fb129%2Fscm69%2Fth_IMG_0515_zpso6gizkbz.mp4&hash=8bfb46434dc3f1782073c2b71fabd9c557e94cef) (http://i18.photobucket.com/albums/b129/scm69/IMG_0515_zpso6gizkbz.mp4)

Title: Re: Dumping boost on throttle
Post by: stacy2704 on February 21, 2017, 10:14:22 pm

also im running a rev g fitted a couple of months ago and have replaced the MAP sensor

Title: Re: Dumping boost on throttle
Post by: pudding on February 23, 2017, 03:09:53 pm

What engine is it?  GTI K03 or Edition 30 K04?  Is it remapped or standard?

You will hear a lot more noises from an induction kit but you shouldn't be hearing any fluttering noises unless the turbo runs into surge.  Remapped KO4 engines often do that at specific boost pressure and rpm (usually around 3000).

Title: Re: Dumping boost on throttle
Post by: stacy2704 on February 23, 2017, 06:31:17 pm

its an AXX K03 with standard map

Title: Re: Dumping boost on throttle
Post by: AJP on February 23, 2017, 07:15:07 pm

Could be the N75 valve. I think there's a way of testing it manually, but you really need to get hooked up to VCDS. It'll save a lot of messing about.

Title: Re: Dumping boost on throttle
Post by: stacy2704 on February 27, 2017, 10:48:16 pm

so i did boost logs but they dont look very good..
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi18.photobucket.com%2Falbums%2Fb129%2Fscm69%2FScreen%2520Shot%25202017-02-27%2520at%252022.40.37_zps7qhmfkov.png&hash=9a67b4e22ec4aa3a9db59777321c121a0f396ec4) (http://s18.photobucket.com/user/scm69/media/Screen%20Shot%202017-02-27%20at%2022.40.37_zps7qhmfkov.png.html)

Title: Re: Dumping boost on throttle
Post by: bradh on February 28, 2017, 06:57:17 am

I had similar turned out i had a slightly leaking boost pipe would dump pressure around 3k then build back up

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Title: Re: Dumping boost on throttle
Post by: stacy2704 on February 28, 2017, 07:12:51 am

was it one of the seals on the pipes? i suspect after 12 years mine may be past their best

Title: Re: Dumping boost on throttle
Post by: pudding on February 28, 2017, 03:26:38 pm

Oil patches on the under tray is a good sign of that happening.

Title: Re: Dumping boost on throttle
Post by: stacy2704 on February 28, 2017, 08:27:21 pm

thing is im sure it opens the recirc on full boos t so i cant see the seals being the main or only culprit

Title: Re: Dumping boost on throttle
Post by: bradh on February 28, 2017, 09:59:11 pm

I replaced the pipes with aftermarket silicon hoses fresh seals no issues since 3 weeks ago I did it


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