Boost Circuit Diagram?

[Westy]

Does anyone have a diagram of the S3 boost circuit? I want to do an inspection of every single boost hose/pipe as I'm still experiencing strange noises that I think are due to a split hose.

I've done a couple of quick checks but couldn't spot any splits so I'm thinking of taking pipes off and giving them a good going over.

 

[Westy]

I've searched the net and am struggling to find anything that is helpful so I dont expect anyone to have any info.

Maybe someone could take a few pictures of their engine bay and highlight the hoses that make up the entire bost circuit. I understand that some of them will be hidden but any info would be helpful.

cheers,

 

[1animal1]

i dont know about a diagram but they are pretty simple to follow, the main hoses are connected via a steel pipe that goes along the front bottom of the engine, the rest is collars and cuffs.... all the pipes on top of the rocker cover and most below the inlet manifold..... simple enough to follow but i would invest in an LED light and mirror tool

 

[Westy]

Cheers tim. I'm getting fed up of the noise like a split DV diaphram when I boost up, i'm sure its a split somewhere!

 

[Essflee]

What sort of noise are you getting, are you sure it's not suppose to make these noises...I get a whistle from the turbo and a whoosh type of sound when I come off, bit like dath vader I find it's loudest when blipping the throttle to 3000rpm and comming off...judging by your graphs and figures I'd say your car seems fine...

 

[Westy]

Yeah It appears that all is fine going on my graphs but when the car is cold and I boost up I get a fluttering noise which sounds the same as a split DV diaphram. The noise is when boosting up and not letting off but it goes away once the car is warm! I noticed it big time yesterday because I haven't driven my car for 4 days then I took it for a spin and it was making the noise. I suspected a hose because the sound goes when the car/hoses have warmed up!

Basically nobody else says this noise is normal and the things people have suggested to check haven't been the cause so i'm just stabbing in the dark now

 

[Essflee]

I agree, my car seems to make more chirping noises when cold, and it feels really really pedal responsive, for about a minute or so which I find strange, it's like I hardly touch the throttle and it's wanting to whizz off...hmmmm strange

 

[speedicar225]

Yeah It appears that all is fine going on my graphs but when the car is cold and I boost up I get a fluttering noise which sounds the same as a split DV diaphram. The noise is when boosting up and not letting off but it goes away once the car is warm! I noticed it big time yesterday because I haven't driven my car for 4 days then I took it for a spin and it was making the noise. I suspected a hose because the sound goes when the car/hoses have warmed up!

Basically nobody else says this noise is normal and the things people have suggested to check haven't been the cause so i'm just stabbing in the dark now

I have been trying to trace noises that seem identical to yours. Engine cold the car "chirps" and the rate at which it chirps is controlled by the accelerator - with light throttle it seems I can drive "around" the noises. The noises only happen when the engine is under load (blipping the throttle in neutral = no chirps). Car warms up and chirping virtually disappears. Warm engine, stop the car and restart and chirps are back.

The car (2001 S3 47k miles and FASH) is going in for a new clutch on Monday, and I will get a Vagcom on it first start of the morning and see if I can pinpoint the cause. To date, I have changed the diverter valve, which initially seemed a cure but was not. My next try will be the N75 wastegate bypass regulator valve IF the Vagcom is no help.

I seem to be able to detect a loss of boost when the "chirping" is present. Simply have to find the cause but do not believe that it is hose related, simply because of the fact that the noise largely disappears with a warm engine, other than when starting.

If you make some progress, praps you could let me know and I will do the same.

Good hunting!!

 

[leshkin]

How about making/buying something like this or this to test for boost leaks? Vag-Check guys in surrey have a home-made one with a simple pressure gauge and worked perfectly to find a boost leak on my car. Try giving them a call and I'm sure they can sort out a quick check for you.

 

[1animal1]

i made a unit similar to this but never actually got around to using it with any effect, firstly you have to block the crank return valve off so that the pressure doesnt damage it, also when you pressurise the system it pushes oil up the engine, i tried twice and on both occasions had blue smoke coming out of the exhaust for 2 mins each time.... i know the vag check guys arent daft but from what i found and from the advice i was given i decided not to do it again

 

[leshkin]

Yeah, they did block the other end and I didn't have the oil burning problem... I guess this is best used with caution and adult supervision

 

[HTC]

Some diagrams here

 

[speedicar225]

Some diagrams here

Much obliged and thanks for your interest.

Have cast about on other VAG turbo websites and it is noticeable that most of the threads concerning the type of noise that is impairing my brain finish with no recorded resolution at all.

Hopefully this one will be different !!

 

[Westy]

I have been trying to trace noises that seem identical to yours. Engine cold the car "chirps" and the rate at which it chirps is controlled by the accelerator - with light throttle it seems I can drive "around" the noises. The noises only happen when the engine is under load (blipping the throttle in neutral = no chirps). Car warms up and chirping virtually disappears. Warm engine, stop the car and restart and chirps are back.

The car (2001 S3 47k miles and FASH) is going in for a new clutch on Monday, and I will get a Vagcom on it first start of the morning and see if I can pinpoint the cause. To date, I have changed the diverter valve, which initially seemed a cure but was not. My next try will be the N75 wastegate bypass regulator valve IF the Vagcom is no help.

I seem to be able to detect a loss of boost when the "chirping" is present. Simply have to find the cause but do not believe that it is hose related, simply because of the fact that the noise largely disappears with a warm engine, other than when starting.

If you make some progress, praps you could let me know and I will do the same.

Good hunting!!

Yep thats identical to mine. I've got VAGCOM but my car doesn't show any errors at all. The reason i was thinking down the lines of a split in a hose was because the noise is the same as when you have a split diaphram on a DV. One of my mates had a hole in a boost hose the size of pin which was untraceable by eye, as soon as some air was forced into the hose it would expand to the size of a 5 pence piece! The only reason I thought the noise went away after the car was warm was because the hoses would get warm/soft and the split/hole wouldn't open as much!!!! Just a stab in the dark though.

I've got to book my car into a VAG specialist soon for some bits to be done so I'll ask them to check the hoses with a pressure test.

 

[Westy]

Some diagrams here

Thanks mate. My searching skills aren't upto much haha. I did a google search first but I was searching for "Boost circuit diagram"

 

[speedicar225]

Yep thats identical to mine. I've got VAGCOM but my car doesn't show any errors at all. The reason i was thinking down the lines of a split in a hose was because the noise is the same as when you have a split diaphram on a DV. One of my mates had a hole in a boost hose the size of pin which was untraceable by eye, as soon as some air was forced into the hose it would expand to the size of a 5 pence piece! The only reason I thought the noise went away after the car was warm was because the hoses would get warm/soft and the split/hole wouldn't open as much!!!! Just a stab in the dark though.

I've got to book my car into a VAG specialist soon for some bits to be done so I'll ask them to check the hoses with a pressure test.

So, update time.

Just returned from MSD, who are doing the clutch and I am recovering from an expensive meeting. Plenty of meat on the clutch, but it has been terminally damaged by oil via a leaking gearbox oilseal, but a replacement clutch was expected. Dual mass flywheel is also damaged and this was not expected.

To get to the "chirping" point: with the gearbox out, access to the turbocharger is very much easier, as is access to the relevant hoses. The turbocharger shows significant bearing wear: insignificant end float but substantial vertical movement of the impeller shaft in the housing. I will put a dial guage on it and report further, but comparing it with a new turbo (where vertical movement is nominally nil) clearly shows the extent of the play and the wear. Whether this is the cause of my "chirps" we will find out when the new turbo is fitted. All hoses looked good.

Incidentally, the air hoses from the turbocharger had evidence of oil mist in them. The understanding is that the bearings in the impeller shaft in the turbo are designed to hold oil pressure to float the shaft in the housing and when the bearings fail, oil is seeps past, thus failing to support the shaft, the oil then gets into the hoses.

So money is flowing out here: clutch, dual mass flywheel and turbocharger, oil supply pipe and gaskets and all plus labour!!.

Internet next to look for the best price for a K04 turbocharger. When the installation is complete and the car is back on the road I will let you know whether it "chirps" or not.

"Chirping" noises = fckd turbo is not what I really wanted to hear!! Wonder whether the vanes on the impeller shaft have been touching the housing, or whether the "chirp" is just dry bearings?????

 

[Westy]

Thanks for the update...... I think

 

[speedicar225]

Thanks for the update...... I think

Last update:

The car was collected from MSD in Llandybie last night. Beside the fitting of a new KO4 tubocharger, the clutch, master and slave cylinders and dual mass flywheel were also replaced.

Again to the point: all turbo noises on start up gone!!! What's more, a hugely improved car as far as performance is concerned.

I will post separately under "Turbo noises" so that the topic can be better reflected in the thread title.

I hope that helps others who are grasping for a cure to the startup "turbo twitter, chatter". I have the olde trurbo and will take it apart at some time, for a post mortem, but the shaft bearings are badly worn and this on a genuine 48k mile, 2001 car with full ASH!!!

However as far as I am concerned, those noises DID equal a f*ckd turbocharger. Other cases may not be, but then again, they may.

Last word: MSD Autocentre (01269 851111) were trusted with the job and again, did an excellent piece of work for sensible money. I obtained the components required.

Jason and MSD come highly recommended and as I have said before, I am a picky olde git!!

 

[vetch]

Sorry to off topic here, Ive already tried PM'ing you Speedicar225, but got no response.

Regarding your use of MD Autos in Llandybie, are they an Audi specialist? I'm keen to find a decent, trustworthy local specialist to work on my S3?

All help gratefully received - feel free to PM me if you'd prefer.

 

[speedicar225]

Sorry to off topic here, Ive already tried PM'ing you Speedicar225, but got no response.

Regarding your use of MD Autos in Llandybie, are they an Audi specialist? I'm keen to find a decent, trustworthy local specialist to work on my S3?

All help gratefully received - feel free to PM me if you'd prefer.

Vetch,

PM sent.

 

[ianysm]

Wow, so possible new turbo time if some wierd noises are present? Mine makes noises (remapped) but i don't think they sound too bad and only under certain circumstances, the car provides constant good boost so i'm not too worried. My girlfriend describes it as a car that runs on air!

It just shows that a so-called low mileage car with full service history means nothing as you can't tell how well its been looked after!

I'd have been tempted with a hybrid upgrade turbo like the JBS05 for a nice 300bhp!!

 

[speedicar225]

Wow, so possible new turbo time if some wierd noises are present? Mine makes noises (remapped) but i don't think they sound too bad and only under certain circumstances, the car provides constant good boost so i'm not too worried. My girlfriend describes it as a car that runs on air!

It just shows that a so-called low mileage car with full service history means nothing as you can't tell how well its been looked after!

I'd have been tempted with a hybrid upgrade turbo like the JBS05 for a nice 300bhp!!

Absolutely agree with your obs concerning a low mileage car!!

What worried me about the turbo was the fact that I had no idea as to how close the thing might be to grenading! If not grenading, the bearings breaking up and pieces being ingested by the motor!

I wasn't interested in the possible 300bhp thing. Judging by posts I've read, things are not always as straightforward as tuners say they are and neither are the figures claimed necessarily delivered. Then there are the insurance issues, let alone matters of uprating all of the other parts of the car to complement the increased performance.

Each to their own and people have got to do what they've got to do. My car will be sold in a few month's time and I know that a standard car in the condition mine is in will be an easier (???) sell than a "claimed" 300 bhp thingy.