Noises!!, Noises!!, Help pls

[Andy9]

Hi everyone, wonder if anyone can help me out with a problem!!!!, I've had my 2004 b6 1.9 TDI quattro nearly 6 months now, 169000 MLS with fsh, since having the car I have spent most of my time sorting out various problems instead of enjoying it ( replacing window actuators/aircon compressor pulley/etc) usual stuff I suppose considering mileage and lack of general tlc and now runs pretty good but wouldn't say fuel consumption is anything to shout about, anyway there is 1 problem I just can't get to the bottom of, I keep getting this grinding sort of noise coming from the drivers right side and it feels air related like a dry sucking /vacuum noise as though coming from the Airbox area ??, and the car seems to pull back as though something is stopping it and loses power, probably limp mode, i have had the Airbox off completely and changed all the vacuum hoses and have also had the intake manifold off (very gunged) and cleaned all with Mr muscle including inside the turbo vanes and also replaced the air filter, upon road testing I thought I had cured the problem but unfortunately not, sometimes it feels as though the turbo is not working (over boosting) accompanied by this dry grinding sound that you can hear whist driving, funny enough it also seems worse whilst cornering ????, I've also checked the Maf by disconnecting it and road testing but the car seemed worse when road testing although I didn't get any engine management light come on when disconnecting it ?definitely seems to come from airbox/ turbo area when blipping the throttle, I have checked for any codes via vcds lite but no error codes, I just don't know what else to do now, I have also disconnected the vac lines whilst engine is running and there seems to be a vacuum, problem is this fault is intermittent and sometimes the car runs great with all power and no noises and then another time it is like this, doing my head in !!, Am I missing something ??, Also not checked n75 valve or the other valve connected but they look ok and if you disconnect them you lose vacuum so thought these should be ok, ANY IDEAS ANYONE PLEASE !!!!!!!

 

[pauldazzle]

You can check the N75 operation with VCDS. IIRC it's in instruments in the engine section.
Grinding when cornering sounds like a dodgy wheel bearing.

 

[Andy9]

Yes your right, problem is the noise is there while car is not moving and is evident whilst revving the engine, whilst I was changing the clapped out compressor pulley I also checked all other pulleys including the alternator clutch pulley which seemed to work as it should although did look the original, and also put a new belt on but keep wondering if it could possibly be the alt clutch pulley as when this noise starts happening the car seems jumpy and pulling back and I just wonder if it could possibility be electricaly related but the dry grinding noise accompanying all this is definitely on the right side ??

 

[sumo]

Have you checked the play in the turbo shaft,from what you say the lack of power and grinding noise sounds like it's on its way out.

 

[Andy9]

Hi, well when I disconnected the exhaust side to t he turbo I managed to get a finger in the turbo and could feel the shaft and managed to turn it, I tried to wiggle the shaft but couldn't really feel any play at all but I have wondered if this could be the noise I'm hearing its as though something metallic is not turning properly and causing a dry sort of grinding noise, is there another way of checking for any play in the turbo ?, Before I did any cleaning of the turbo vanes I did check whether the actuator was moving properly and it seemed a little hesitant/ sticky and so I pumped a load of Mr muscle into the exhaust side of the turbo and worked the actuator over a 2 hr period, funny though I can hear the turbo spin up normally when the car is " normal" but I must admit I don't seem to hear it when this noise is present, hmm!!, Thanks ever so much for your help, andy

 

[Andy9]

Problem as well is that I am used to a 1.8 20v petrol and never had a TDI before so I am a little unsure of how these engines work anyway, still learning !!!

 

[sumo]

Take the inlet side off and check the shaft and fins for any bent or deformed ones. A couple of mm play is ok.bent fins are not.

 

[Andy9]

Ok sumo, thanks for you advice, beginning to wonder if this is where the problem lies ?, be a few days before I can check but will keep you posted, cheers, andy

 

[aragorn]

Its hard to say without hearing the noise, but i've never heard a grinding noise from a turbo. They whine or screech when worn out. They spin too fast and have too little inertia to create a grinding type noise.

 

[Andy9]

To be honest aragorn it could be dry sort of whine or dry bearing noise as though something is not turning properly, I'm not used to a turbo and don't really know what type of sound to expect, when I say grinding sound the noise happens as I rev the engine from idle and as the revs drop back down this dry sort of noise, it is definitely on the right hand side just in front of me as though it's from the front wing area and I thought to look at the Airbox area that seals against the inner wing but I can't see anything wrong, when this is happening the car is pulling back upon acceleration as though it being starved of something (air,electrical ??) but will idle normally but upon moving off I cannot hear turbo spin up and car seems to lose power and is pulling back, I have been trying to get to the bottom of this for weeks and I am virtually at a point of taking the car in to a garage as I don't know what else to try

 

[Darran]

do a boost test using vcds and then you will see whats happening.

 

[Andy9]

Hi darren, can you perform this test yourself or is it a garage job ?, At the mo I only have vcds lite but I am going to invest in a vcds 15.7.1(crack version), would I be able to perform the test using this and do you know the correct procedure to carry out the test, much appreciated andy

 

[Darran]

Yes you can diy with full vcds, just search how to on here or google.If your anywhere near derbyshire i can do it ,theres plenty on here that can but need to know where you are roughly?

 

[Andy9]

Hi Darren, thanks ever so much for you offer, I'm in Leicester, I'm gonna invest in vcds, not had chance to look at car properly as to busy but I'm beginning to think it could actually be the turbo, aragorn said the other night that turbos "whine" when worn, and I begin to wonder if that's it, I have listened to this noise as im driving and really the noise is there all the time but more pronounced sometimes more than others and when this noise is louder I seem to lose power and the engine seems a bit rough, given my car has 169,000 on the clock and the turbo looks original its probably time for a replacement, do you know how long they last on average ?, my car has fsh so I would think has had regular oil changes, I think I'm gonna get this boost check done first before I start replacing turbo though, I was looking at replacement turbo components on the bay and was wondering if I could refurb my existing unit, it look any easy enough job if it works!! and would be cheaper ?

 

[Darran]

Not worth rebuilding yourself imo i only use these ppl.ivor searle, never had a problem with their turbos and they are rebuilt properly and BALANCED in the uk! Even if you rebuild your own you still have to have the core balanced which is why a lot of these asian aftermarket turbos go pop.!

 

[Andy9]

oh I see, thanks for telling me, to be honest I can't really afford another £300payout, might have to look at secondhand, what actually is making this noise in the turbo is it excess free play in the shaft as when I took the exhaust side off I got my finger inside and couldn't feel any side movement at all but I didn't check from inlet side, don't know whether to strip down again and give it another go cleaning the vanes with Mr muscle

 

[Darran]

To be honest mate without actually hearing it i cant say?



You are sure your not hearing a boost leak are you, if its a boost leak it will throw up over boost fault and the hoses are common for splitting?

 

[Andy9]

I replaced all the vac hoses with new braided hose as the old ones were ok but a little burnt in places from engine contact, I can't see anything that looks wrong, although driving car today car drove ok but couldn't hear turbo spinning up on acceleration like I sometimes can and engine seemed a bit laggy, when I originally tested turbo actuator motion by observing it did look a bit sticky but did move and I cleaned inside of turbo with mr muscle while moving actuator and the car seemed better for a few days with crisp acceleration with no noises and I thought I'd done it but it seems Im back to square one
Hmm

 

[Andy9]

Hi guys, abit of an update, after talking to a couple of vw/audi specialists in Leicester about the problem one said the noise i'm hearing is turbo flutter? and could be a number of things causing it (not very helpful) and other was quite helpful and said it could be a worn turbo and advised me to check turbo shaft for internal scoring, i have today taken both sides connected to the turbo off and used a mirror to have a look at the shaft as close as poss, while looking reasonably clean on the inlet side there does seem to be quite abit of movement in the shaft mainly on the exhaust side but there is no actual damage to any of the blades, trouble is looking at it i cant decide whether the shaft movement is excessive or not, there is no actual scoring on the inlet side but i can see some light scuffing where the blades rotate, is this normal and permissible or is the turbo had it ??, can you guys give me your advice on this, ive looked at various videos online about checking permissible turbo play and some have them the same amount of play and are said to be ok but im not sure, i have also check for excessive play by pushing against the shaft slightly but there doesn't seem to be any, i do wonder if the noise im hearing is the blades touching the turbo body internally while accelerating but the puzzling thing is its not all the time sometimes the car runs fine with all the power and no noises and sometimes mettalic grating noise and lack of power and pulling back, i at least should have vcds in the next few days and im gonna try and do a boost leak test as darran said
any help will be gratefully received as always, cheers, andy

 

[Andy9]

upon close inspection today using a mirror i can see there are some score marks on the exhaust side of the turbo housing where the blades have been catching it slightly, it dosent look excessive but they are there and what seems like abit of sideways play in the shaft, should i be looking for a new turbo ? dont really know the best option ?, i cant really afford a brand new turbo at the mo and might have to look secondhand or reconditioned, (not telling the missus!!! )(missus thinks car parts last forever!!), upon roadtesting it today the noise is still there and i got my son to rev the car with bonnet up while i listened and the noise is definately coming from the turbo housing

 

[sumo]

Hi Andy, when a turbo usually let's go its the intake side that will have signs if rubbing and bent fins on the impeller not the exhaust side.look more on the inlet side,can you do a short clip to demonstrate the play?

 

[Andy9]

hi Sumo, actually upon removing the exhaust side and inlet sides of the turbo to be honest i didnt think it looked to bad, there did seem to be a bit of slight scuffing where the blades had possibly brushed against the housing and once i managed to check the freeplay in the shaft on the inlet side i was abit alarmed how much there was but upon looking on youtube at some other turbo shaft freeplay vids i wouldn't say it looked any worse but i would say there was a bit more play on the exhaust side and i did notice there was some score marks on the turbo body but again not excessive.i did manage to try and take a couple of small videos of this while the inlet vid being better than the exhaust side, i will try and upload the videos for you to see, while the exhaust was off i again cleaned the exhaust side of the turbo with mr muscle and worked the actuator which now seems free and smooth,and left some in overnight to loosen up any carbon deposits (probably shouldn't have done that but hey!!), yesterday after i reasembled everything and took car for a roadtest and initially was fine (no smoke at all) but i did start to hear the noise again so i pulled over and got my son to rev the engine while i inspected it and this noise is coming directly from the turbo housing more on the exhaust side when reving and as the car drops back down to idle, and upon checking other videos on youtube last night i would swear it is turbo flutter, again upon reading on the forum last night it seems this could be due to a faulty N75 valve and i am now inclined to think about replacing this first, i will be getting my vcds 12.12.3 next week and wonder if i can check this out properly.Today i have drove car and it is fine with all power,i dont really feel like paying out for a turbo when the car drove as good as this, im puzzled!!!!! (il try and upload vids) cheers, andy

 

[Andy9]

Here are the vids , i know there not brilliant but gives you an idea, sorry i just dont know how to upload vids, can anyone help please!!

 

[Andy9]

finally here are the vids hope they work ?

 

[sumo]

Judging by the last vid Andy that looks like too much play, if you hold the shaft up can you get the blades on the inlet side to touch the housing?

 

[Broken Byzan]

fubar

 

[Andy9]

Hi, I'd say yes, there is some light scuffing where the blades have been touching the housing and if I wiggle the shaft about I suppose it would touch the sides more, the exhaust side seemed a bit worse with some score marks where the blades had dug in more, is it time for a new turbo ?

 

[Andy9]

One other thing I did notice while the shaft/spindle would turn free enough i couldn't actually spin it, is that right?, On a couple of videos Ive seen the shaft seemed to spin very freely by hand ?

 

[sumo]

I think you know the answer to your original question Andy,hand in pocket time fella.

 

[Andy9]

Hi Sumo, yeah I think your right really, I also think it on its way out, offhand would you happen to know the nut size that hold the turbo on, are they 13mm ? and are they brass ? although they look quite corroded and look as though they could be abit awkward to get at and a pain to get out, I wonder if it would be easier to remove the exhaust manifold with the turbo on ?

 

[Andy9]

Following my earlier post, can sometime point me in the right direction on how to complete a turbo boost and N75 valve check with vcds, do I complete using "output tests" or is there another way, I would liked to have eliminated the N75 or any other component related to the turbo before I start pulling and renewing the turbo itself. (AVF) engine