VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: olly_p on February 12, 2012, 11:27:23 am
-
Hi i am from the uk and my friend has a Mk2 gtd golf.....and is having a boosting problem, once the boost gets to 0.9bar it backs off to 0.5bar the climbs up again then backs off again.....just had a 2 1/4 straight through exhaust put on also no difference made still backing out at 0.9bar! Any ideas?
Thanks Olly
-
what intake manifold is it equipped with? the one with an integral blow off valve? sounds almost exactly like the BOV is opening and releasing pressure.. either that, or more than likely, a stuck waste gate.. its VERY common on KKK turbos for their waste gates to be finicky..
what turbo does it have? a K14 or a T2?
-
Hi yes that's it, sounds like its dumping the boost kkk14 turbo/
-
Hi yes that's it, sounds like its dumping the boost kkk14 turbo/
so, it boosts up, and then WOOSH, your boost is gone?
i would figure out for sure if your buddies car has a over boost protection valve (blow off valve) and if it does, i would just stuff a wine cork in the outlet of it, or else spend a few bucks on the machined aluminum block off plate..
when i was still running a stock VW intake manifold on my diesel, i drilled a hole thru my over boost valve, stuck a rubber grommet on the bolt, and ran it thru the valve, using the grommet to seal the pressure side of the valve off from ever opening again..
or, more than likely, it doesnt even have a over boost protection valve, and its just got a sticky wastegate..
(http://images.thesamba.com/vw/classifieds/pix/2545137.jpg)
witch of these intake manifolds does his car have? the style on the left, or the style on the right? see that round piece off to the left hand side of the manifold, above the intake runner for cylinder #1? thats the overboost valve, and it was only on the earlier turbo diesels.. later engines had that piece removed from the factory, because it was an un-necessary piece to keep the engine functioning properly..
i imagine it probably has a stuck wastegate. does it have a boost controller? because to be making over ~.5 bar (7-8psi) and the stock wastegate will be open.. if its making ~.9 bar (13-14psi) then it DEFINITELY has a sticky wastegate..
if it DOES NOT have a manual boost controller, and its boosting to .9 bar, then its time to pull the wastegate off, and clean it, possibly even replace it if its in too bad of shape..
-
Basically you floor it, boosts up to 0.9 backs off to 0.5bar (makes a noise as if its dumping boost) then climbs back up to 0.9 then back to 0.5. I has not got a blow of valve! here is a picture when when had it in bits
(http://i2.photobucket.com/albums/y43/olly3000/DSCN0002.jpg)
Thanks Olly
-
(http://i2.photobucket.com/albums/y43/olly3000/DSCN0005.jpg)
-
Basically you floor it, boosts up to 0.9 backs off to 0.5bar (makes a noise as if its dumping boost) then climbs back up to 0.9 then back to 0.5. I has not got a blow of valve! here is a picture when when had it in bits
(http://i2.photobucket.com/albums/y43/olly3000/DSCN0002.jpg)
Thanks Olly
you do too have a blow off valve!!
its the black round thing clamped to the manifold above the runner for #1 cylinder.. that thing opens @ ~15psi (1 bar)
-
Ok.....sorry didn't realise that was a blowoff valve, to be honest I would not have thought it would have one......bit surprised. Ok how can I stop it?
-
You need this kind of plate and clamp.
(http://forumbilder.se/images/703201221632P45e2.jpg) (http://forumbilder.se)
-
Where would I be able to get one?
-
The FAQ had instructions once on how to kill your BOV. I would read through there, when I read it, it was fairly cheap and easy to do.
Unscrew the small plug, cut a bolt or small round metal bit to fit, screw the plug back in. No more BOV.
Brad
-
not to mention, i already informed you of a couple different ways to disable the blow off valve, while leaving it intact..
-
Thankyou for your replies!