2.5TDi V6 quattro Sport 180hp Turbochip

better but not fixed, still gutless then boosting then gutless again. Think that i'm gettting a turbo whistle when boosting, quiet when not. tried Adamss24 high rev driving for 40 - 50 miles this morning and other than crucifying the fuel consumption no permanent improvement. Came off the motorway onto the A30 and got away from the lights twice no smoke, next set clouds of black and low power again.

I am sure i have read somewhere that there is a temp sensor in the pressure sensor, i now have a new one anyway.
 
Make sure your EGR valve isnt leaking under boost conditions, like this you will dump the fresh air your turbocharger compresses into the exhaust. To be sure install a stainless plate between the pipe leading from the EGR vane to the intake.

If that doesn't cure the problem I would think the vanes of the turbocharger are sometimes sticking.

B.R

Stefan
 
OK will think about blanking EGR, i also suspect a sticking actuator on the turbo as i said before . If you rev the engine in neutral how much should it move? I thought i needed to get the engine under load to get the full movement?
However this afternoon i unplugged the MAF and drove a short distance. It appeared to make no difference so i am going for a longer drive tonight to see. Maybe the MAF i replaced is faulty.
 
if you have access to a mityvac you can check the movement of the actuator and see if the diaphram is holding a vacuum. it will show you if you have a sticky vane. I wouldnt think that it could be sooted up as of the enthusiastic driving style.
 
I think the car is sooting more with the big injectors and modded map than a stock trim car. Especially at low RPM's/low boost, just in which position the vanes like to stick. disconnect the actuator and move the lever by hand, it shouldn't have any resistance moving back and forward, if it does keep moving it about.
 
So i waited till it was really dark and went out with my unplugged MAF and spread soot around the airport like Concorde had just taken off. Initially i thought yep there's definitely an improvement here, bottom end pick up much quicker and smoother. Maybe i was less inhibited because i couldn't see the smoke. So i did about 10 miles around the motorway and then pulled off and plugged it back in. Well maybe there wasn't that much difference but still have a niggling doubt it ain't right. So then i really went for the driving continuously at high revs, stuck it in 4th and constantly accelerated up and down from 3000 to 4500, fortunately there wasn't that much traffic about and the M25 has lots of lanes. When i got on to the 2nd loop it freed off and the torque came back for a bit, back to demolishing the 80+ acceleration, but it didn't last. I probably did 50 or 60 miles like this up and down the motorway and it felt better by the end of it, and i was beginning to get concerned i would attract attention from the smoke and 3 figure speeds. By the end it was just smoking if i accelerated hard,but i could do more smoke free than than previously. Coming back into town i was able to pull away from the lights relatively smoke free but not very quick, theres no torque at the bottom end still. The back of the car looks like the inside of a chimney sweeps bag this morning, and its still smoking. Going out this evening so will have another furtle about tomorrow.

PS whats a mityvac and where do i get one?
 
audi upgrades
a mityvac is a sort of hand pump used to bleed brakes. it can create vacuum (suck) and has also a setting where it can build pressure (pump).

There is something wrong that you won't solve just by driving the car hard. Is your EGR system bolted shut with a plate between the pipe ? If not do this, you will not only eliminate this as a possible cause, but also keep your intake much cleaner (no more soot entering the intake)

B.R

Stefan
 
With the engine off the vanes should be in the high rev/high load position, when starting the engine you should see the lever move to the low rev position almost instantly (vanes in position to make max boost at low revs)
 
Tossed in a new Pierburg MAF yesterday for good measure, never having been quite sure of the last one i put in. Engine noticeably smoother, but not the root of the problem. We'll get a better idea on the 260 mile blip home this evening. Will look at the actuator arm movement this weekend when i have an assistant for the drivers seat while i furtle under the bonnet.
 
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Ok took all the suggestions and this evening fashioned a high tech blanking plate for the egr from top grade bottom of a sardine can and slipped it into the manifold end of the egr pipe. This must be one of the most expensive mods ever, not. Checked the movement of the turbo actuator and it does move as soon as the engine is running, but have not measured the travel. Disconnected and reconnected the battery. Went for a 15 mile run and performance is noticeably better, more torque and more revs. Smoke is noticeably less rather than clouds of black more of a haze. Can still provoke a cloud but much much better. Big step on the road to recovery i hope. So Stef, wherever you are, i owe you a drink.
 
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If your EGR has been sticking open, it might be worth cleaning your intake manifolds, as they'll likely be gunked up and with your extra fuelling mods, you really want the engine breathing nicely!
If you have VCDS, basic settings 11 (I think) will actuate the turbo vane actuator on and off every 10 seconds at idle, so you can check the movement. If it doesn't move fully, see Evilscotsmans thread on Mr Muscle turbo cleaning!
 
:) glad to hear there is improvement.
Be careful with the thin plate you made, I once made one from 2mm thick steel plate and after 1 year there was a hole corroded right through. It seems the exhaust gasses work pretty corrosive on ordinary steel, that's why I now use a stainless plate.

I will have another go at flashing my ECU in the next days, I hope I don't mess up or I will be doing quite a bit of cycling the next week :)))

I'm from Belgium

B.R

Stefan
 
Whats the car like when you turn off the engine? The flap inside the egr prevents the engine juddering at switch off im told just wondering if there is any vibration.
 
Paul - yes the same thought occurred to me, i need to find time to do the manifold
Stef - yes i need a thicker plate but had nothig to hand and the tin was so thin it slipped in without any forcing the egr pipe away from the manifold, i just wanted to prove the point. I hope i can pick up a piece of stainless at some point
This morning on the 260 mile blip to work the car went much better, the smoke is much less the power is much improved and the fuel economy up. :arco:
 
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Swarcup - hadn't noticed any particular judder at shut off but will check. Its been so long since the egr was disabled i can't rmember what standard is.
 
yes, that is also worth checking, it could be the shutoff valve sticking in an in between position, not allowing enough air to pass. However it won't be in the solenoid or the vacuum tubing because the engine just would stall and wouldn't start since then the valve would be totally shut. If it gets stuck near halfway however because it is blocked mechanically it could be giving the symptoms you describe. you can easily feel if it sticks or not.

I finally fixed my power window at the drivers side, new mechanism, works great ! As I was enjoying this the Bose amplifier or the RNS-E gave up just a few minutes later, I only have the Bose subwoofer working ... A quick look at the connector of the Bose in the boot showed corroded pins and a stinking a bit burned. Cleaned everything, no joy :-s
 
I blanked mine off last night. a mate of mine gave me a plate a few months ago and its only reading this that reminded me. The egr pipe that connects to the inlet manifold has a larger connection at one end to the other, the smaller being on the manifold end so ive fitted mine to the egr valve on the exit side as the plate was for the larger size connection.As for results i have only done about 10miles but it sems like the turbo is more eager to go from lower down. no change to tick over or smoothness. will have a look at the mpg when ive refilled today and used some up. Going in for an mot tomorrow, do you think it will effect the emissions? who knows will see if the test centre fail it on the smoke test but it runs pretty clean, smoke is only really visible at night with headlights behind.
 
Swarcup - shut down with no judder. As far as emissions are concerned there will be some increase as the egr won't be letting the engine reburn some of the exhaust but given the way mine smokes and it still passed i'd be surpried if you failed the MOT. what would cure it properly would be a remap.....
 
a remap or box is on the list but the flyweel is showing signs of its age and its in tomorrow for the mot and while its in a fettle up of the front suspension.will fund this and then when ready will boost her up.
 
Think i might have burnt through the tin already, need to check but about to go on hols - using the A4 as wife doesn't trust the A6 and it does about 10mpg more too handy for driving to Spain
Some **** hacked my personal email yesterday and was sending scam email to everyone in my address book saying sob story about how i'd been mugged in Madrid and asking for money to get home - £1250 send to some western union bank. They'd diverted all my email to another address. Robbin barsteds.
 
So that was the holiday, 2750 miles through france and spain. Its when you get on the french motorway and the sat nav says "turn in 313 miles" you realise its bigger than the uk. Have more respect for the A4 now, it just gobbled it up.

Anyway back to reality. Pulled the sardine tin today and its still in one piece. Thats not helpful as after the initial hoorays a few weeks ago the power had faded away again and the smoke was back and i thought the tin might have blown through. Pulled off the inlet manifold today losing a tinchy drive socket and extension piece into the engine undertray in the process. It was well coked up and we are not talking the white stuff either. I didn't have time to take off the cylinder head sections, just the bit across the front of the engine, and i ran out of cleaning solvents anyway. Put all back together and went for a run up the road, still smoking and down on power. Stopped to get the tyres pumped up after 2 weeks standing and disconnected the battery for 3 or 4 minutes while i was doing it. Went for a 15 mile bimble and theres no change. Well thats back to smoky joes for tomorrows return to work then, shame as had it professionally valeted as a present so its pretty clean at the mo, will be sooty again by lunchtime
Sardinetinblockoffegr.jpg

Inletmanifoldbeforecleaning2.jpg

Inletmanifoldfirstsectionaftercleaning.jpg
 
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After 60 or 70 miles this morning it got a lot better. The only thing i noticed i might have done that was associated with the change was using the cruise control. Is there any way this could affect the power? Wasn't consistent but it was still good when i got here and the fuel economy had climbed by 3 or 4 mpg. Anyway enjoy while i can.
 
You might want to get an intake manifold set from a scrappy, and get it ported/gas flowed. With your upgraded turbo giving shedloads of air, and your fuel system giving loads of fuel, smoothing out the airflow path may well give you a much crisper response. Remember any smoke is fuel looking for air to burn!
The stock manifolds are pretty lumpy inside and full of sharp bends and castings. You could get this done and then just replace your set instead of taking yours apart and cleaning. It would be better to get the heads done too, as mentioned earlier in this thread, but I think cleaning the lumps and bumps from the airflow would help a lot with efficiency, which translates to power, or economy.
 
Yes could do that but way back at the start my intention was to see what i could get by effectively using bolt on extras, i didn't want to get into internal engine mods. A lot of what i have done has been to get the components working right, remember the old lady is 10 with 230k miles this month and is starting to feel her age i think. We've spent a lot of time tracking down issues of old parts that are worn, and i suspect there are probably some other bits that could do with cleaning like the manifold. If i went out now and found a newer car with half the mileage, bolted on the hybrid turbo bigger jets and got the remap it would probably jump to 250hp straight away with none of the problems. If she settles down now and i consistently have power i will get remapped again to cut the fuelling back a bit to reduce the smoke and improve the mpg (any number starting with 3 would be good).
 
Still smoking but more go consequently thrashed home on Friday. This morning started off nice and peppy, went sluggish and bottom end torque went, but fuel economy remains better than it was.
I have noticed that when its going better it leaves a pale haze at wider throttle openings rather than black smoke. think this may be oil, It definitely runs better when the oil is low. Oil consumption has reduced since i only topped it up halfway recently, so much so i thought the low oil level sensor/warning light had packed up, but also since i blocked the egr. However the light came on this morning so have just topped it up fully so we'll see.
 
Thought i had bettered 30 mpg on the last tank but 29.9 only, was giving it a bit too much stick on the last bit on Friday i suppose. However this is the best for months. Checked around all the hoses yesterday, got half a turn or so on some of the circlips but nothing major. Checked the turbo actuator, when you start the engine it doesn't move instantly but after a second or two it lifts right up.
Best trip for weeks this morning. Wet n horrible weather to start with, car was a bit smoky and listless but after 8 or 9 miles seemed to get its act together and stayed that way until i stopped a 100 odd miles later. Went all sluggish then so turned it off and on again and it came back again. When its going better i can roll on to 4k rpm without too much smoke being steady with the throttle but if you push too fast it can't cope and smokes.
Have just found this site https://sites.google.com/site/1810martin/home/b5-vnt-turbo-problems and printed off the details. Going to have a work through some of these this week.
 
I think with the amount of soot the engine chucks the turbo's VNT mechanism is getting hard to adjust (from min boost to max boost) as well hence the slow output...
 
I am worried that i may end up stripping the turbo to clean and or repair but as it is the most expensive thing to do i am working towards it doing all the cheaper things first. The very basic things i have done have made perceptible differences, so i still hope it is going to be a simple one when i finally track it down. Both the Celtic mechanic and the Falmouth Garage mech looked at the turbo and couldnt see or feel anything wrong from the outside. I have wondered about asking you to take a look, its just working out the logisitics of doing without the car in London for a few days.
 
Well now. Virtually normal service was resumed this morning and i spent 4 hours ******* off sports cars. Smoke minimal. So whats different?

Filled up on Friday night with normal Shell diesel not V Power (i filled both cars at the same time DO NOT DO THIS £178 aarrgghhhhh).
Then drove 150 miles below 70-75 in convoy with wife back from Bristol where the dally has been taken for a spinal op god bless dog insurance (about 38mpg haven't worked it out yet).
This morning it was raining for the first 20 miles or so but that didn't last all the way, showers here and there.
After i stopped for coffee it thought about it for half a mile but then carried on.
The oil light came on after 200 miles or so so it was low.

Answers on a post card....

Even going off and on the throttle into roundabouts where its always smoked i was getting a brief poot of smoke and then clear. It still won't take WOT without lots of smoke, maybe less smoke if the turbo is fullly boosted, but that could be down to the map, he has tried to pack a lot of fuel in at the top end. This is the first time its really started to behave itself since the new intercooler and radiators went in. I am getting 4000- 4500rpm rpm if i press steadily rather than flooring it. If it stays like this i may be tempted to dyno it again so we can remap.

Mystified but happy, but not at all confident its gonna last.
 
It didn't.

Checked vacuum pipe system as far as i could at weekend.
As the brakes work and the engine starts and runs i do not think there is a problem with the vacuum pump
N75 is disabled and blocked off but i checked anyway. No leak
Intake manifold flap was thoroughly cleaned when i did the inlet manifold,is audibly snapping shut and there is no judder on engine shutdown so OK there
Turbo actuator pipe cannot blow into it so no leak. Actuator moves up when engine starts but only about 8-10mm. Its against the stop but as it should be moving 15-20mm i assume there is a problem at the other end of the travel. As i have recently replaced the actuator N75 i am assuming that it is OK. With the engine running if i pull the pipe off the actuator it drops, and picks up again when reconnected. I was unable to make the actuator move more than a mm myself by sucking on the pipe to the actuator.
To my mind this leaves the following options: there is an actuator problem, a turbo problem or the MAP sensor is broken.

This morning it started ok but i am starting to disappear up my own harris trying to remember if its a bit better or worse. By the time i arrived at work it smoking as usual and gutless. If it hadn't been for last Monday i would have forgotten what it could be like.
 
i havnt read all the thread and appologise in advance if this has been done, but when you installed your injectors where they pressure tested and shimmed to even out the pressure for each one so they where the same. I ask this as a friend of mine went through a similar issue of smoke and power fluctuations and it was because the injectors where simply bought and wacked in with out being setup. This was resolved via dieselbob and when refitted made a massive difference and cured all issues. Just a thought and again sorry if you have already done this.
 
I only replaced nozzles not injectors. Prior to this current problem the car was going fine, so i don't think its a problem with the injectors. Getting the pop pressures balanced has been on my list of things to do but at present i can't be without the car while the injectors are pulled sent away and reinstalled. Maybe i'll contact dieselbob and ask for a price and how long it takes. I am currently running Miller diesel additive after seeing how sh1tty the intake was and thinking how much of the rest of the inside could be similarly coked up.
 
Interesting read about the two stroke oil - seems to have no disadvantages - Brands Hatch this weekend so will add suitable dose before setting off - bit more than 1:200 mix as 143000 on clock and let you know how it goes - bit happier with this idea than lots of others I've read about - chip shop oil etc:beerchug:
 
we're off to St Austell for the week on Saturday so picked up a 250ml bottle of mower oil tonight and will fill up tomorrow to test it out.
 
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