Taken the downpipe of and can see and feal both sides of the turbo no side play a little in and out,no marks on finns they are all ok and it spins freely.a lot of work butIhad to rule out a damaged turbo,but where to look now Ihae no idea.
-
-
Intercooler???The Perfectionist
sigpic
Audi Class Concours winner Stoner Park 2014, ADI Concours D'Elegance Class Winner 2008, Runner up 2014. Winner, S2Forum Show'n'Shine Billing 2006 & 2008.
Comment
-
Pressure tested the intake track and its fine.Comment
-
Injector seals on the inlet manifold ?sigpicComment
-
Timing marks all line up ok?Comment
-
? really confussed now
Comment
-
Realy nackered now,put the car back together and its just the same,no boost what so ever,it is running ok starts first time.tickover is fine,just this noise and no boost, not even mechanical boost.
Tomorrow I will check the timing and swap a few bits over from my s6 as a last resort.
Today I have done a leak test of the intake track and it holds pressure, taken the wastegate of and dissmanteled it all ok,checked the turbo spins ok,injector seals and inserts are new,put a little air into all the vac hoses and they hold.
If you guys can think of anything please let me know co's I am out of ideas .Comment
-
Lou,
Are you pressure testing before the turbo or after it?Comment
-
Robin I took the bottom pipe of the turbo put a bung in it and placed the valve in the acordian hose,thuss bypassing the turbot it was as tight as a drum.
I pressure tested it the otherday through the maf hose and could hear it bubbleing into the sump,Comment
-
Which DV are you using? Bosch plastic or aftermarket aluminium type? Take it off and inspect it.
You can also remove DV, bung the 3 hoses where DV connects and take it for a short spin, just to rule out the DV. I have experienced leaking DV when turning up the boost close to those levels, even Forge (had to put in a stronger spring).
Don't give up
when you get it fixed you know it's worth the trouble
Leif-Helge
-91 S2 VEMS and Comp Turbo
-12 B** 530XD Touring "S2 parts transporter, and daily driver"Comment
-
I am useing the stock bosch DV which I have had of the car and vacume tested and it holds,today I am going to replace it with the one from my s6. I am useing the standard wastegate spring whch as far as I know has never been changed,so I wjll take your advice and change for the uprated 1.9 bar spring and a new diaphram.
I have connected an air line to the pipe running from the n75 to the wastegate,which is back on the car and I can hear it operating the piston,also done the same one my s6 with the same results.Comment
-
Lou,
I was wondering whether you had effectively bypasssed the turbo.
I am not sure whether the bubbling in the sump is indictative of a fault.
I guess we might be looking at the turbo. Not sure whether it is actually "new" or a a rebuild. Clearly the compressor side should effectively be airtight. There is a big O ring that seals the comp housing to the seal plate but I would have thought if you pressure tested throught the turbo it would have been obvious if it was leaking.
Another possibility might be the turbo itself. If its under warranty then there is no point messing with it. Perhaps there is a comp whel issue (loose or damaged) that prevents it building boost.
In the post by DKW above, I think he is recommending a stronger spring in a Forge DV not the wastegate!Comment
-
Robin The turbo is new but it was bought from a forum member and there is no warranty.
If there is an issue with the turbo that causes .0 boost would it still spin and not boost.
With regard to the bubbling in the sump while pressure testing through the maf hose I beleive several people on hear get this.Comment
-
Have you still got the old K24? If so I think I'd stick it back on just to be sure. Be careful though cos that chipset will likely overspin it.
Re the boost spikes, I had problems with this, turned out my WG was smaller than it should have been, from a 10v maybe, either from the factory or changed at some stage, showed up real bad when I fitted the GT3071 and 3" exhaust, I was getting the boost climbing at high rpms in the high gears even with the WGFV disconnected, might be worth a look.Comment
-
Lou!
I am using the Sherlock Holmes method of deduction!
At the end of the day its the turbo that makes boost. If you have eliminated air leaks and the wastegate is closed then you should be seing boost.
If there is no leakage from the back of the compressor housing then it might point to the comp wheel being loose or damaged. It might be the wheel is tight enough to spin on the shaft by hand but not at 100,000 rpm. Naturally without removing the comp housing you will not be able to see whether there is any damage to the major part of the comp wheel. Whilst removing that part is not difficult, it would be wise to try and source a replacement O ring seal from perhaps a reputable turbo recon place as its not available through VAG.
Again not knowing the origins of this turbo I can only comment on what I discovered dismantling a genuine one. A genuine RS2 turbo has a left handed thread and waisted shaft. This is used when to prevent the comp wheel loosening when stalled by shutting the throttle. If you have a genuine RS2 turbo it should have those bits. If its a replica then it probably won't as they are expensive and rare compared to regular K26 stuff.
I know it's a PITA but can you not stick the old K24 back on temporarily to eliminate the turbo?Comment
Comment