no turbo kick/ticking noise

m8arx

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i've only had my s3 since yesterday and it seems like there's no turbo kick whatsoever until roughly 5k, and even then it's barely noticable.

when i start the car up, there's a ticking noise that sounds as though it's coming from the back of the engine that only happens when you rev it, it doesn't do it on idle. thought it might be a heatshield or something, but it doesn't seem thats whats causing it.

I've been reading about boost leaks etc, and sticking a vagcom on it.

without having a set of ramps, does anyone know which pipe's could be causing this/best way to diagnose the problem?

cheers
 
Theres a couple of pipes which could be causing your issue matey.

They are mainly associated with the N75 (electronic boost control solenoid) and the turbo's actuator.

Turbo should be spooling up way before 5 K.

Get it on a diagnostic machine (thats what VAG COM is really).
 
Welcome pal. As good as people are on here at helping, there's too many things that could be causing your problems. You really need to get it hooked up to VAGCOM to give us/you an idea of what's going on, otherwise we're just stabbing in the dark. Saying that, normal things to look at are spark plugs, coilpacks, boost leaks, MAF sensor. Leaking PCV pipework under the inlet manifold has given people alot of trouble lately aswell, something to do a search on :icon_thumright:
 
cheers boys - i know it was a bit of a thumb in the air question, but i don't have a vagcom at the moment. one of the boys in work has one he bought from ebay that can read the codes etc, but i'm not sure what good this will do if it's not the full version.

i had noticed a few posts about the pcv.

i'll try and see what the vagcom says on monday, but in the meantime - any ideas what the ticking noise could be?
 
cheers boys - i know it was a bit of a thumb in the air question, but i don't have a vagcom at the moment. one of the boys in work has one he bought from ebay that can read the codes etc, but i'm not sure what good this will do if it's not the full version.

i had noticed a few posts about the pcv.

i'll try and see what the vagcom says on monday, but in the meantime - any ideas what the ticking noise could be?

You sure it's coming from the back of the engine? The injectors are very noisy on the 1.8T and the charcoal chamber also 'ticks' but thats at the front of the bay
 
aye as far as i can tell mate

the cars going to be off the road until i get a new caliper delivered and fitted cos it's binding the pads and discs (piston's gubbed), so once i can drive it again i'll see if i can get it up on some ramps and see where it's coming from.

whats this charcoal chamber?
 
Hmmmmm. Could be a blowing exhaust manifold - that often sounds like a tick. Not really much else that is down that way that can tick that I can think of.

The charcoal chamber is to do with emissions. Collection of evaporated fuel I believe. Ticks like buggery at times.
 
Hmmmmm. Could be a blowing exhaust manifold - that often sounds like a tick. Not really much else that is down that way that can tick that I can think of.

The charcoal chamber is to do with emissions. Collection of evaporated fuel I believe. Ticks like buggery at times.
 
Yeah, day after I bought my S3 I had this ticking noise aswell and thought something was seriously wrong, but turned out to be the charcoal filter. The filter seperates the fuel from the vapour given off from the fuel tank. The fuel goes back to the tank and the clean vapour goes into the TIP/inlet manifold. Thats the only ticking noise I can think off.
 
i'll take all the covers off today and see if i can tell where its coming from and post here, wont have the vagcom until monday

cheers for the pointers so far guys :)
 
cheers mate - there's 2 about 30 miles away from me - not too keen on driving it any great distance without knowing what the issue is first. i'll see what the vagcom says on Monday (i think it's the read only version that a boy in the work bought from ebay - not sure how good this'll be.
 
removed the 5v turbo cover and noticed a hose going to the pipe from one of the intercoolers had a hose completely loose from it. i slipped it back on and jubilee'd it tight.

the pipe seems to come from the air filter intake but i'm not sure exactly what it is. haven't taken the car for a drive because of the caliper problem, but i will post up here if this was the problem once i can drive it.

this is it below

pipe-vi.jpg
 
thats your pipe doing to you d.v. This will very much hinder performance. Go round feeling pipes for spits etc, especially under the inlets, but be careful when breaking the dipstick tube lol. Theres a few non-return valves doted round the engine that are worth checking. Main ones being the ones on the PCV system, these get gunked up and stop holding back.

Geting somebody to rev car while feeling around for leaks will help you find any obvious ones.
 
cheers sportstractor, i'll check the pipe's later today :)
 
right guys - i got a loan of a mate's vagcom cable and the shareware version to read the codes.

the following codes were reported for the engine

17705 - Pressure Drop betw. Turbo and Throttle Valve (check D.V.!)

and

16486 - Mass or Volume Air Flow Circuit - Low input (at least i'm sure it was this one!)

I used the software to clear the code, read the ecu again and the code's were indeed gone. I then took it a drive again, still no real kick from the turbo, parked up, read the codes again and the ecu showed no errors (i'm not sure if the drive was long enough to really give it any errors).

i don't want to spend any great deal of money testing and trying this that and the next thing, but i can't seem to find any leaks/cracks in any pipes at all :(

when the engine is being revved, should the pipe's "expand" and be solid with the airflow or should they stay fairly soft? mine's are fairly soft, and to be honest i don't know if this is correct or not.

short of taking it to a garage, anyone got any other idea's apart from checking pipes?
 
Is your motor standard? What dump valve do you have?

I am currently experiencing the dreaded 17705 error too, can't shake it.


Possible Causes


  • Leaking hoses and/or pipes between components
  • Check Boost Pressure Control Valve (N249)
Possible Solutions


  • Check hoses and/or pipes between components
  • Check / Replace Boost Pressure Control Valve (N249)
  • Check / clean Throttle Valve, do Throttle Body Alignment
 
I would suspect your MAF is ******** looking at the first code, and the 2nd was caused by that DV pipe being off.
 
car is completely standard guys.

would the MAF make the turbo not kick though - it's as if there's no boost at all (there obviously is, but it's not enough for me to fell the kick)
 
Try unplugging maf, then take for a short drive. The 17705 faults sometimes requires the car to be driven hard before it will pick it up depending on how bad the leak is. 17705 is a leak no doubt. If your not confident removing and checking pipes etc probably better going to a garage. Like said before most leaks will come from pipes coming off the bottom of the inlet manifold. I found 3 or 4 on mine! smoke test even missed one of them when I had it orginally tested
 
Try unplugging maf, then take for a short drive. The 17705 faults sometimes requires the car to be driven hard before it will pick it up depending on how bad the leak is. 17705 is a leak no doubt. If your not confident removing and checking pipes etc probably better going to a garage. Like said before most leaks will come from pipes coming off the bottom of the inlet manifold. I found 3 or 4 on mine! smoke test even missed one of them when I had it orginally tested


How hard is it to get under the inlet manifold?
 
bit fiddly, have to take take the metal plate off with the 2 allen key bolts. I slid the whole pcv system out to check the pipework, not an easy task but do-able
 
ok here's an update folks

had the s3 on a "launch master x431" or something like that, which is like a vagcom but apparently better.

it picked up the MAF fault again, so i went and got a oem bosch maf sensor brand new, fitted it, and still no boost :(

i don't believe there's any boost leaks cos we simply can't hear any air whatsoever.

i'm taking it to ava tomorrow to get it on the rollers, but i really can't afford to throw money at it - anyone got any other suggestions to what the hell it could be?
 
Ok, i've not been able to get anyone with a vagcom to measure any blocks yet, but i have had it on the rolling road. there's virtually no boost at all, and only above 3k does the boost begin to creep up but it's about 2psi if i remember correctly.

the guys seem to reckon it could be the wastegate not opening and remaining shut/almost shut, which is why i'm getting nothing at all.

it's going up on a ramp tomorrow to see if they can have a look at the turbo, blades etc but has this ever happened to anyone else?

how much is a new turbo fitted? anyone got any threads on replacing the turbo with pics?
 
after thinking my turbo was goosed, we think we've found *part* of the problem.

The turbo is definately still working (at least it seems that way). There's definately turbo kick, but it doesn't really come into play until about 4-5k.

the actuator rod seemed seized for whatever reason, we've freed it up, but the rod might actually be slightly bent inside the wastegate itself - won't know until i get the turbo off.

i've already changed the maf sensor before i was even getting any boost.

before i get the turbo taken off, is there anything else that could be causing it to not boost until around 4-5k?

cheers

Mark
 
come on guys - someone must have a few recommendations. i've already pmmed 2 people on here in scotland who have vagcom according to the map, but none have got back to me. there must be someone who's had this problem before that might give me a pointer rather than taking turbo off (as this is what the problem seems to be pointing to)

vagcom is definately a good thing, but if i don't have it and i can't get anyone to measure these blocks i'm a bit stuck - so really just looking for a pointer or ten.

cheers
 
Ok, i've not been able to get anyone with a vagcom to measure any blocks yet, but i have had it on the rolling road. there's virtually no boost at all, and only above 3k does the boost begin to creep up but it's about 2psi if i remember correctly.

the guys seem to reckon it could be the wastegate not opening and remaining shut/almost shut, which is why i'm getting nothing at all.

it's going up on a ramp tomorrow to see if they can have a look at the turbo, blades etc but has this ever happened to anyone else?

how much is a new turbo fitted? anyone got any threads on replacing the turbo with pics?


its not wastegate shut chap... else it would boost massively high (if its capable).. maybe wastegate stuck open however..
if you have means to pressure the pipe to the actuator to see when it starts to open.. one other thing to try, is bypass the n75 valve and feed the boost direct into the actuator, so it should run on actuator only boost which is usually 5-6psi.. if it does start to produce some boost then, its an indication the turbo "wants" to spool up and try to produce boost.

laggy as **** turbos i have seen, which have not had stuck open actuator, have had damaged compressor wheels, which dont flow well at all, just thrash about in the air. they will look curved and bent over and rounded edges if shagged

good luck finding it
 
bill - cheers - i have managed to put pressurized air into the system and the actuator rod definately moves, meaning the wastegate is working, but you're right, i did mean stuck open earlier and not stuck shut :)

whats the best way to bypass the N75?

finesse - cheers, awesome help.......
 
get some silicon pipe or rubber hose or even a small joiner.. and connect the pipe which goes to the base of the n75 to the pipe which goes down to the actuator.. so the boost can only direct on the actuator
you should get 5-6 psi, but not lag... k04 should be spooling just over 2krpm... if its later than this, then I fear the turbo's goosed in some way

good luck
 
Cant i just disconnect the plug going into the n75 and take this out of the equation or does it work even if this is unplugged?
 
you can electrically unplug it yes.. removing it form the circuit completely check if its having an adverse effect tho
 
cheers bill

i bypassed the n75 completely, it did seem more responsive, but then again, i'm not too sure if 0.4 bar should give enough "kick" to notice.

is there any way to get the normal 18psi running through it without the n75?

don't really want to spend 75 quid replacing the n75 when it makes no difference and i end up having to get the turbo out anyway!
 
yeah thought that - i've posted up if anyone's from my area.

could it be the n75 do you think?
 
is the s3 n75 the same as an a3 180bhp n75?
 
ok well, tried another n75 and still the same. turbo's coming off :(
 

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