MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: B1NCC 1.8T on February 14, 2016, 12:34:25 pm

Title: GTI with lack of boost. Help
Post by: B1NCC 1.8T on February 14, 2016, 12:34:25 pm
I have a mk5 GTI giving me boost/ lack of power problems.

It blew the turbo a few months ago (didn't blow up and throw pieces everywhere tho- just kinda seized the properller) I replaced turbo with genuine KO3 not a cheap dung thing from eBay. It came with a brand new N75 valve and modified diverter valve.
The car also has a new PVC valve at some point recently. 
The fuel pump tappet thing is in good condition too. Fuel pressure figures within spec

Currently its not holding boost.  It has a boost gauge fitted and when out on road it boosts to 25psi but quickly drops off to 10psi but holds at 10.
Car has a huge alloy intercooler with silicone boost hoses , 3" decat and a full stainless exhaust. Also im told car is remapped. It's also a DSG.

I've taken all the pipes off and checked for leaks etc also checked the rubber sealing rings between the other boost hoses.

No real faults in VCDS either. Once it's came up with the EVAP fault. Which they all seem to have lol. Also it once came up with a MAF fault.

Wondering if anyone can help me any further. Maybe I've missed something
Title: Re: GTI with lack of boost. Help
Post by: bacillus on February 14, 2016, 01:12:57 pm
Looked at the DV to check for torn diaphragm?
On a ko3 the dv is bolted on to the turbo housing.
Title: Re: GTI with lack of boost. Help
Post by: B1NCC 1.8T on February 14, 2016, 01:37:06 pm
Diverter valve Is brand new modified piston type
Title: Re: GTI with lack of boost. Help
Post by: Bo! on February 14, 2016, 06:04:43 pm
Is it possible the intercooler has a small split somewhere .?
I had same issue on my old Leon boost would spike up and tail off to a certain point. had a boost test carried out at a specialist and it turned out to be a split in the intercooler .
Title: Re: GTI with lack of boost. Help
Post by: B1NCC 1.8T on February 14, 2016, 06:15:24 pm
Is it possible the intercooler has a small split somewhere .?
I had same issue on my old Leon boost would spike up and tail off to a certain point. had a boost test carried out at a specialist and it turned out to be a split in the intercooler .

Thanks for the reply mate. I was beginning to think the fancy intercooler might have a leak. But there's a lot of ideas flying about in my head just with this car lol.
I will get a smoke test done on intercooler.
Thanks mate.
Title: Re: GTI with lack of boost. Help
Post by: r5gtt on February 14, 2016, 06:33:38 pm
Hi what was it like before the Turbo seized?. was throttle response perfect or was it lacking boost?
Title: Re: GTI with lack of boost. Help
Post by: Toek162 on February 14, 2016, 08:10:17 pm
Any codes
Title: Re: GTI with lack of boost. Help
Post by: B1NCC 1.8T on February 29, 2016, 06:41:36 pm
Back on this one.
Did a smoke test on the whole intake/boost system and ruled out any boost leaks.
Intercooler is spot on (unforunalty)

Still no fault codes

Also stripped down the fuel pump and check the pump tappet for wear. Both the cam and the tappet are mint condition.

I never drove the car before the turbo failed.
Title: Re: GTI with lack of boost. Help
Post by: ROH ECHT on March 01, 2016, 02:33:38 am
My guess is there isn't enough preload on the actuator rod...if the actuator diaphragm itself and the N75 are new...the DV mod is fine...no boost leaks are detected...and finally, there can be no leaks in any of the vacuum lines and the lines at the N75 and actuator diaphragm must be properly clamped.

Given that all the leak tests have been completed and the list of new bits mentioned...I would definitely turn the nuts on the actuator rod a couple of extra turns(2mm) towards the actuator diaphragm...away from the internal WG valve.

With engine cooled and the heat shield for the right-side axle boot removed:
Remove clip #1...back off the #2 nut three full turns (approx. 3mm) towards the actuator diaphragm...snug the #3 knurled nut toward #2 nut and tighten #2 with your 10mm wrench...replace clip #1 and retest.
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi1205.photobucket.com%2Falbums%2Fbb434%2Frohecht%2Fbcc306dd-df1e-4f3a-9dba-e4656d841566.jpg&hash=557d301037461df46e49e820de9e053a95367e9d) (http://s1205.photobucket.com/user/rohecht/media/bcc306dd-df1e-4f3a-9dba-e4656d841566.jpg.html)
Title: Re: GTI with lack of boost. Help
Post by: Beej on April 10, 2016, 10:00:13 am
Sorry to jump into someone else's thread, but got a wee question.

I tried adjusting mine yesterday (lying under car on drive) got the clip off, but loosened, but could not get the knurled nut bit to budge, then to add insult to injury, spent the best part of an hour trying to replace the clip with no joy. Made sure the nut was firmly snugged back up and left it, as I need the car.

Any tips for getting this knurled nut to spin?
Title: Re: GTI with lack of boost. Help
Post by: r5gtt on April 28, 2016, 09:51:47 pm
@Beej (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=11339)

Plenty of WD40 or a blow torch of the hand held kind if you have one. I do lol
Title: Re: GTI with lack of boost. Help
Post by: Beej on April 29, 2016, 07:46:41 am
@r5gtt

It's extremely tight even trying to get a decent set of grips up there and still be able to see what you are doing never mind a small blow lamp, but I can see where you are coming from.

I am going to attempt to have a go from above, as I am not left handed, and from underneath, it favours the left handers out there!
Title: Re: GTI with lack of boost. Help
Post by: r5gtt on April 29, 2016, 06:09:42 pm
@Beej (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=11339) Maybe the thing turns the opposite way and you're actually tightening it?  :thinking: just a thought remembering you need to undo the 13mm nut first.  :signLOL:
Title: Re: GTI with lack of boost. Help
Post by: Beej on April 29, 2016, 06:12:08 pm
The thought had crossed my mind, but then I realized that I had already loosened the nut, so the knurled nut must spin the same way....

I am thinking its either seized or just extremely tight, so I will give it a go from above, see if I can access it.

In the meantime, I ordered a dv+ today
Title: Re: GTI with lack of boost. Help
Post by: r5gtt on April 29, 2016, 06:15:57 pm
You'll love having the gfb dv +  :happy2:

Not saying you haven't but try turning the thinner nut thing as that may help. or its way too tight because of the heat it has to handle. or maybe give it a go when it's hot but now I'm being silly  :stupid:
Title: Re: GTI with lack of boost. Help
Post by: Beej on April 29, 2016, 06:20:53 pm
The diagram on the previous page shows plenty of space and shows it should be easy to adjust it, and it would be, if it was off the car! Lying on the drive under the car trying to access it, and then try to reposition your hand to actually attempt to turn it is not simple! If it were just two nuts it would be a doddle, as I have manged that before!
Title: Re: GTI with lack of boost. Help
Post by: r5gtt on April 29, 2016, 06:24:04 pm
Trust me I know the feeling of lying under the car as I tried yesterday and it didn't work so I had to take the wheel arch liner off to replace the DV + lol

Couldn't get my hand up the underside even though my hands arms are tiny  :signLOL:
Title: Re: GTI with lack of boost. Help
Post by: Beej on April 29, 2016, 06:57:13 pm
I didn't even try doing the dv last year from underneath, just went in through the wheel arch!
Title: Re: GTI with lack of boost. Help
Post by: Beej on April 30, 2016, 08:24:56 pm
Dv+ now fitted, just need to have another go at this actuator rod.....
Title: Re: GTI with lack of boost. Help
Post by: r5gtt on April 30, 2016, 08:28:44 pm
 :congrats: wheel arch way is best without a ramp anyway  :signLOL:

Let us know ho you get in with it?.
Title: Re: GTI with lack of boost. Help
Post by: Beej on April 30, 2016, 08:30:36 pm
:congrats: wheel arch way is best without a ramp anyway  :signLOL:

Let us know ho you get in with it?.
Yeah, wheel off, liner off, pretty accessible. 30/40 mins, job done, thread locked the bolts in
Title: Re: GTI with lack of boost. Help
Post by: r5gtt on April 30, 2016, 08:32:31 pm
:congrats: wheel arch way is best without a ramp anyway  :signLOL:

Let us know ho you get in with it?.
Yeah, wheel off, liner off, pretty accessible. 30/40 mins, job done, thread locked the bolts in
I took 40 minutes as the bolts coming out were so tight I slipped the bit one two of them  :scared: but they came out and the third one disappeared down the steering rack area lol
Title: Re: GTI with lack of boost. Help
Post by: Beej on April 30, 2016, 08:39:10 pm
:congrats: wheel arch way is best without a ramp anyway  :signLOL:

Let us know ho you get in with it?.
Yeah, wheel off, liner off, pretty accessible. 30/40 mins, job done, thread locked the bolts in
I took 40 minutes as the bolts coming out were so tight I slipped the bit one two of them  :scared: but they came out and the third one disappeared down the steering rack area lol
Typical eh?! Yeah, I remembered doing it last year, thought about this time though and used a ball head long allen socket, much easier, but hopefully, I should never have to remove it again!
Title: Re: GTI with lack of boost. Help
Post by: r5gtt on April 30, 2016, 08:50:51 pm
:congrats: wheel arch way is best without a ramp anyway  :signLOL:

Let us know ho you get in with it?.
Yeah, wheel off, liner off, pretty accessible. 30/40 mins, job done, thread locked the bolts in
I took 40 minutes as the bolts coming out were so tight I slipped the bit one two of them  :scared: but they came out and the third one disappeared down the steering rack area lol
Typical eh?! Yeah, I remembered doing it last year, thought about this time though and used a ball head long allen socket, much easier, but hopefully, I should never have to remove it again!
I had ally tools at work so was struggling with what I had  :doh: didn't even have a 17mm spanner to hand and had to use a pair of jaw type adjustable pliers  :slap:

No never again as these gfb dv +  look the nuts. how's the car driving and was your old dv diaphragm torn?.
Title: Re: GTI with lack of boost. Help
Post by: Beej on April 30, 2016, 08:54:31 pm
:congrats: wheel arch way is best without a ramp anyway  :signLOL:

Let us know ho you get in with it?.
Yeah, wheel off, liner off, pretty accessible. 30/40 mins, job done, thread locked the bolts in
I took 40 minutes as the bolts coming out were so tight I slipped the bit one two of them  :scared: but they came out and the third one disappeared down the steering rack area lol
Typical eh?! Yeah, I remembered doing it last year, thought about this time though and used a ball head long allen socket, much easier, but hopefully, I should never have to remove it again!
I had ally tools at work so was struggling with what I had  :doh: didn't even have a 17mm spanner to hand and had to use a pair of jaw type adjustable pliers  :slap:

No never again as these gfb dv +  look the nuts. how's the car driving and was your old dv diaphragm torn?.
I haven't driven it yet, only done it half an hour ago. No it wasn't torn, I fitted rev g last year, but I've heard some stories of the diaphragm actually stretching???? Not sure what difference that would make, even if it were to though
Title: Re: GTI with lack of boost. Help
Post by: r5gtt on April 30, 2016, 08:56:18 pm
:congrats: wheel arch way is best without a ramp anyway  :signLOL:

Let us know ho you get in with it?.
Yeah, wheel off, liner off, pretty accessible. 30/40 mins, job done, thread locked the bolts in
I took 40 minutes as the bolts coming out were so tight I slipped the bit one two of them  :scared: but they came out and the third one disappeared down the steering rack area lol
Typical eh?! Yeah, I remembered doing it last year, thought about this time though and used a ball head long allen socket, much easier, but hopefully, I should never have to remove it again!
I had ally tools at work so was struggling with what I had  :doh: didn't even have a 17mm spanner to hand and had to use a pair of jaw type adjustable pliers  :slap:

No never again as these gfb dv +  look the nuts. how's the car driving and was your old dv diaphragm torn?.
I haven't driven it yet, only done it half an hour ago. No it wasn't torn, I fitted rev g last year, but I've heard some stories of the diaphragm actually stretching???? Not sure what difference that would make, even if it were to though
The over stretching would loose you boost as it won't open fully?.  :slap:  :signLOL: I love that slap emotion  :grin:
Title: Re: GTI with lack of boost. Help
Post by: Beej on April 30, 2016, 08:58:13 pm
:congrats: wheel arch way is best without a ramp anyway  :signLOL:

Let us know ho you get in with it?.
Yeah, wheel off, liner off, pretty accessible. 30/40 mins, job done, thread locked the bolts in
I took 40 minutes as the bolts coming out were so tight I slipped the bit one two of them  :scared: but they came out and the third one disappeared down the steering rack area lol
Typical eh?! Yeah, I remembered doing it last year, thought about this time though and used a ball head long allen socket, much easier, but hopefully, I should never have to remove it again!
I had ally tools at work so was struggling with what I had  :doh: didn't even have a 17mm spanner to hand and had to use a pair of jaw type adjustable pliers  :slap:

No never again as these gfb dv +  look the nuts. how's the car driving and was your old dv diaphragm torn?.
I haven't driven it yet, only done it half an hour ago. No it wasn't torn, I fitted rev g last year, but I've heard some stories of the diaphragm actually stretching???? Not sure what difference that would make, even if it were to though
The over stretching would loose you boost as it won't open fully?.  :slap:  :signLOL: I love that slap emotion  :grin:
Yeah, that was my thinking, but wasn't too sure. Some of the emoticons are excellent!
Title: Re: GTI with lack of boost. Help
Post by: r5gtt on April 30, 2016, 09:01:17 pm
:congrats: wheel arch way is best without a ramp anyway  :signLOL:

Let us know ho you get in with it?.
Yeah, wheel off, liner off, pretty accessible. 30/40 mins, job done, thread locked the bolts in
I took 40 minutes as the bolts coming out were so tight I slipped the bit one two of them  :scared: but they came out and the third one disappeared down the steering rack area lol
Typical eh?! Yeah, I remembered doing it last year, thought about this time though and used a ball head long allen socket, much easier, but hopefully, I should never have to remove it again!
I had ally tools at work so was struggling with what I had  :doh: didn't even have a 17mm spanner to hand and had to use a pair of jaw type adjustable pliers  :slap:

No never again as these gfb dv +  look the nuts. how's the car driving and was your old dv diaphragm torn?.
I haven't driven it yet, only done it half an hour ago. No it wasn't torn, I fitted rev g last year, but I've heard some stories of the diaphragm actually stretching???? Not sure what difference that would make, even if it were to though
The over stretching would loose you boost as it won't open fully?.  :slap:  :signLOL: I love that slap emotion  :grin:
Yeah, that was my thinking, but wasn't too sure. Some of the emoticons are excellent!
Dont take offence to them that's all  :drinking:

I think I'll check mime of the sun's out tomorrow. weather check now.