2.5TDi V6 quattro Sport 180hp Turbochip

[swarcup]

thats great news post a pic when shes back

[fjtwelve]

Rats - not ready. Will be back during the week then my missus will be driving it to Birmingham before i get back in hers. Sigh
Sons car going for MOT tomorrow. He left it late, in fact was due Friday, so checking tonight after all the shops are shut he needs new windscreeen wiper, brake fluid, oil was on the bottom of the dipstick. Hold on this is my car he's driving. Mutter mutter.

[fjtwelve]

Oh and its not ready AGAIN now because they bought the wrong bumper. Yes this one should have headlamp washers in it like the one you took off. Why me? Grump. And the Clio failed the MOT another £200. I feel like a fleet manager, the A4 will need a service soon and the tax is up on it too.

[icenutter]

Car repairs always seem to take longer than they say they will.

[fjtwelve]

Car has landed back at house today. Have recieved some grainy phone camera shots from son#1, looks tidy but can't really tell. Wife refuses to drive it till i came home on Friday in case she or someone else scratches it. Is missing grille around drivers side front foglight, so far Audi have sent 3 through, all for the wrong model.

[quattrojames]

I hope you're happy with it all when you see it on Friday!

[fjtwelve]

New grille popped in this afternoon.

I appear to have been promoted - Moderator eh. Just behave you lot.

[quattrojames]

I appear to have been promoted - Moderator eh. Just behave you lot.

Me too

[fjtwelve]

Shiny new toy
<

[Byzan Pics]

Me too ;-p

[quattrojames]

Cars looking very nice, is it running well?

[fjtwelve]

Weell there was this Focus RS that looked quite nice in my mirrors this morning he either bottled it or ran out of horses somewhere North of 130, have just had my quickest commute up to LHR other than at the dead of night, so yep shes going OK, just turned the 220k yesterday. Still need to get to the bottom of this fuel starvation issue. Thinking of replacing the top of the fuel filter assembly completely after reading something somewhere the other day.

[fjtwelve]

Hmm . Suffering from loss of power above 3k rpm and mucho smoke under load and more than half throttle opening, back of car covered in soot. Wondering if something has gone phut or have a boost leak somewhere.

[fjtwelve]

Had a bit of a furtle this evening and am pretty sure we have a loss of boost somewhere. I can squeeze the flexible hose that comes out of the intercooler when the engine is revved (by the wife, my arms aren't that long) and that used to go rock hard as soon as the turbo spooled up, theres a bit of soot on the turbo around the N75 and the actuator arm movement seems jerky. There is a high pitched whistle/whine from the turbo too which is new.

[fjtwelve]

Here we go again. Moved the car from the hotel to the site car park this morning, and halfway there lost all power car would only tick over flashing glow plug light and the ESP light on. Engine would only run at idle so chugged into the car park. Engine restarted and revved ok. Handbook says flashing glow plug light means ECU problem. Just feckin great. Am just going out to the car park to see if it will run. In the words of Captain Oates "i may be gone some time".

[fjtwelve]

Started ran did 6 laps of the local 3 roundabout circuit at steadily increasing speed no issues. drove home no issues (cruising at below 85 instead of as quick as possible = +4mpg by the way). into celtic on friday, diagnostic says boost n75, maf/map and throttle position sensor. well duh had pegged 2 of these as possibles already. i still think the n75 is up the swanee. anyway had a maf in the boot so replaced that when i got home. seems to be slightly better on a run around town but tomorrow will tell. spent yesterday afternoon polishing the wifes a4 as displacement activity

PS forgot to say the celtic mechanic liked my drive so much he just bought an Allroad 2.5tdi 180 for himself. Cost him a grand when his mate got pikked off with spending too much on bits. Popped in a new set of cams. Not sure what else he's going to do

[fjtwelve]

The new MAF has made some minor difference but still torqueless and smoking like a smokey thing. Going back next week to get the N75 and throttle switch swappped. Gave the engine compartment a spring clean yesterday and it looks not bad for 10 years on. The joy of aerosol Gunk!

[fjtwelve]

Celtic tried to order the N75 today Audi said theres 3 different N75s which one do you want? I said try turbodynamics they supplied the turbo and N75. sigh. Anyway in on Monday. Oh and guess what, just as my wife arrives in Scotland today in her 1.9TDI the ECU problem light starts flashing at her like mine did and the cruise control has stopped working. Pure unmitigated joy.

[adamss24]

If they go by the chassis number they should be able to get you the right one for AKE engine. Missus's flashing light might be due to a faulty brake switch, check that first.

[welshstu77]

Had the tick over only,glow light flashing and esp light on prob on my 2002 a4 2.5 tdi quattro 180 a little while ago.If you turned it off and restarted it it would rev again.seemed trying to snatch a quick gear change or high gear low revs acceleration would bring on one of these episodes.Pengelly garage in callington cornwall had it for a while and eliminated maf problem or pump edc failure and eventually it was a faulty turbo pressure sensor(less than £50 part)happy days!been tempted to get re mapped but reading your thread fjtwelve has made me think maybe leave it standard!great thread mate,boy you are more patient than i!!

[fjtwelve]

As ever adamss24 is right again, she's been into audi carlisle and they have replaced the brakelight switch which has cured the problem.

Mine got its mojo back last night after a very frustrating trip back. Was starting to run low on fuel and hit the Amesbury roadworks jam near Stonehenge thought beggar this and headed into the countryside with the sat nav doing its nut. After 30mins through some very pleasant countryside got back onto the A303 with the fuel light on. Cut a long story short of ever increasing economy driving i ended up putting over 75litres in the tank, most ever. Oh yeah, £113 for a fill up. Words fail me. Anyway getting out of the garage i waited for about 100 cars to go by and then plodded into another jam. Cut over to the M5 at Taunton and started venting my frustration on the fast lane. After a bit we got to a no power won't go faster than 85 whatever i do. beginning to worry i wouldn't get home i was thinking of anything i could do and was doing the Ayrton Senna tapdance on the throttle pedal thinking either the throttle position sensor might get joggled back into life or the boost gauge might get fooled into accelerating. After a bit there was a few missed beats fuel starvation style oh here we go where's that number for the AA i thought. Then she started to respond to the throttle. Well those lads in the Seat Leon who'd flown by earlier got a doing, then the BM 325i and oh yes almost full service was resumed. The A30 shot past in a happy blast of giving it large from 80 to 120 and we did see 137 on the sat nav at one point. Left a bike behind on the wiggly bit from Truro to Falmouth, embarassing for him i think. Get in! Smoke has reduced too, and around town today the smoke is much less. I have no clue what has happened. There is a new layer of black dust around the N75 since i cleaned it last weekend. Anyway still taking it in on Monday for Celtic to have a furtle. Have given her a wash and polish today for being a good girl.
welshstu77 do not fear the reaper sorry remap. If your engine is in good nick the celtic remap will make it oily smooth and significantly better, others probably will too but i have no personal experience, even a tuning box will improve things - see quattro james. Most of my tale of woe above is to do with tracking down and replacing duff bits. bear in mind mine has now done 224k miles. If yours is an AKE and has been serviced/oil changed every 10k miles things should be in reasonable nick, if its a BAU engine you have nothing to fear from cam problems. I'm off next week so if you want to meet up and see the difference no problem. Patience? naw just from the don't let the barstewards grind you down breed crossed with a healthy dose of bloody obstinate.

[fjtwelve]

Changed the throttle position sensor but still smoking, but not as much. Cause of smoke moneys on a blocked injector or a turbo problem causing whatever the funny noise is - its more of a scream than a whistle at times. Still going ok though. Will wait until all the bank holidays are out of the way until i check it in for further investigation.

[welshstu77]

Thanks for offer of comparing difference will have to take you up on that sometime.I used to collect from walkers place next to celtics year or two ago and im sure i seen your motor in there being fettled(fair chance by sound of it eh lol)will prob let them do any re map that i go for mate.my a4 is due a service now(10000 or annually)she is on 97000 now fsh all old mots to prove so im hoping no nasty suprises in the near future.fingers crossed!im very interested to hear what a 3" stainless sounds like on yours cos im fancying a new exhaust in the future too

[fjtwelve]

Ahhh back to the lack of go again and smoke,. Had been optimistic we were on the road to recovery after a week at home pootling around but not so. Whatever jiggled into place 10 days ago has jiggled back out again. She'll cruise ok and make her way up to 3 figures but theres no oomph.

[fjtwelve]

Back into Celtic next Monday. They say they can now log from my ECU on the fly which they haven't been able to do before (the joy of having a 10 year old set of electronics) so hopefully that will help find the problem. The screaming turbo noise has disappeared but i still reckon the boost control is still wrong either over (causing a limp mode) or under (overfuelling) . The power came back again this morning for the last 60 miles, the fuel economy on the DIS went up 3 mpg and the smoke almost disappeared. This was after i'd stopped after about 200 miles to fuel up. I am starting to think about the temperature sensor. I had a problem of the power dying on my old Passat which could be temporarily fixed by turning ignition off and back on again. VW Edinburgh diagnosed a new turbo for £1000 , my then local garage in Lockerbie fixed it - replaced the temp sensor and it cost £15.
Getting hacked off with this now, taken the enjoyment away and its costing me 50 miles a tank at least, put a new record 76litres in last week i can see me running out soon if i keep pushing it. It was easier working in Dublin, at least i could drop the car in for the week, now i need to take a day off work.
By the way tried Autoglym Bumper Care at the weekend, i now have black grilles again and shiny sills and black rubber window seals. Apart from the fact it looks like particularly unpleasant snot in a bottle i was startled at the difference. What with the Meguires wash and the Autoglym polish i'm in danger of posing. If it wasn't for the fact the back of the car is completely covered in soot and the rest gets coated in jet fuel dusted with sand and a trimming of seagullsh1t every week that is. Clean for at least an hour a week now

[fjtwelve]

VAGCOM no fault codes. No mechanical faults found anywhere, but replaced jubilee clip holding hose from airbox onto turbo as suspected wasn't tightening up. ordered N75, the AKE one is the only one that the local parts wholesaler does Not hold in stock.

[fjtwelve]

I now have an N75 for the boost control. Theres 2 sitting side by side, same part number, one for EGR one for boost, only difference externally is colour. Anyone know the difference? Anyway having ordered both and returned the one i didn't need (egr electronically disabled), i haven't yet fitted it as the bloody car is now behaving itself much better, much less smoke, noticeably better pick up at low revs and will coast along at idle in sixth without juddering. This started to happen halfway home on Friday night for no apparent reason. Because i am plonking around grockle filled lanes all weekend i can't properly test drive to see exactly whats changed. My missus drove the car this morning and immediately said what have you done to it, the difference was that marked. It is still smoking at larger throttle openings and going from closed to open throttle eg take your foot off to slow then put your foot down again, but mostly less. That can probably be fixed by cutting the fuelling back a bit but i want to get this intermittent problem sorted before we fiddle with the map again.

[fjtwelve]

Bloody thing went like a train all the way here this morning. Not completely smoke free but back to its old self in terms of roll on grunt and bottom end pull, didn't do any flat out stuff , fuel economy back up. So the N75 is still sitting in its plastic wrapper in the glove box. Obviously it knows its being threatened. I'm still wondering if i should replace the G42 intake air temp sensor. Other possible problems could be the G71 manifold pressure sensor or the pipe to it being blocked or kinked. Maybe with oil, maybe all the moving around of all the pipes has dislodged something.

[fjtwelve]

And last night went back to smoky slugbucket. Unplugged N75 connector, low power and no smoke atall and the idle judder was a bit better. Changed the N75, i might have imagined momentary power but did not cure the problem. Unplugged N75 from EGR just to check, made no difference. By then it was dark i'd done a lot of laps on the A30 by the airport and i was getting tired and emotional so gave up. Today tried unplugging MAF made little difference. So maybe i have a dud "new" MAF.

[fjtwelve]

Drove home Friday and yes halfway home vroomm off we go again all the way to a gnats under 140. Left the car at home this morning and took the wifes A4, so she can take A6 in for the service Thursday (the joys of working away from home). She's just phoned to say having just driven back home from picking up son #2 she can't get it into any gear, the AA man can't find a problem, and they can't tow it because the towing loop has disappeared out of the wheelbrace box. She says why can't we just roll it off the cliff in front of the house.

[fjtwelve]

I was hoping the securing pin/bolt in the linkage under the car had come adrift and would be an easy fix. No such luck. Falmouth Garage had it up on the ramp today and whatever the problem is its inside the gearbox. May need to drop the box. as far as the power problem is concerned have told them to replace the G42 air temperature sensor anyway. They said they'd have a look for a wiring fault too. If i'm lucky they'll have a towing loop lying in the shop they can give me. That'll take the pain out of the bill, oh yeah.

[fjtwelve]

wrong! Told a bolt to linkage at turret on gear box now nylocked and glued so the little focker better not come off again. Managed it without dropping gearbox. Serviced today but the mechanic is still ferreting around looking for the intermittent fault. Audi sent them the external air temperature sensor not the manifold sensor despite being given all the part numbers and specifically being told which one they wanted. It threw a MAF fault again amongst others today but he's been in and out driving and fault clearing. Leaving it there til Monday so he can finish off what he's doing. Could be on the train Monday.

[fjtwelve]

A4 to work, that needs a service and new tyres now. Anyway on to better news, Falmouth Garage have told me that the intermittent power is now fixed since the air temperature sensor has been replaced (a complete biatch to access apparently) but unable to prove this myself as in London for rest of week. However there is still fresh soot on the turbo so something is still blowing although all the bolts are tight. Anyway, progress.

[swarcup]

Good to see your on the mend again, i was always led to believe that the air intake temp sensor on the 2.5 engine is built into the maf. Is there another? bet your dying to get back foer a road test.

[fjtwelve]

Yep there is somewhere, other than causing the mech to put his head in his hands not sure, the air temp after its been through the turbo and intercooler is going to be different than coming through the MAF i suppose.. yes now twiddling my thumbs (well would be if work wasn't so busy) waiting to get home to drive it. The wife said it was much better and less smoky on a drive around town today. Just hope this is n't another intermittent recovery. Manifold air pressure sensor will be the last place to go i think. I am dangerously assuming that given 2 experienced guys have crawled al over it they would have checked that the vane actuator on the turbo isn't sticking

[blackwagon]

Hello,

I think the intake temp sensor is integrated in the boost pressure sensor that sits in the pipe coming out of the IC and going to the intake. It is indeed difficult to reach.

What I noticed on my 2.5 Tdi 180hp is each time I cut battery power, the car goes much better afterwards. Pulls much better (measured 0.9 secs quicker 0-100km/h with VCDS) consumes 0.7l/100km less and runs smoother. This effect wears of in the next 3 days (about 300km). I guess it has something to do with adaptations the engine ECU does while driving (rather poorly :-))

Have anyone of you encountered this phenomenon ?

Best regards

Stefan

[swarcup]

Im going to try this to see. it makes sense that it measures the air intake temp after the intercoolers. so why in the maf also?my last fault read said air intake temp sensor fault but just put it down to me disconnecting the maf when driving? possibly wrong will get another scan.

[blackwagon]

There is definately also a temp sensor in the MAF, you can see it when you look inside the MAF.
I think they use that to estimate the air density, the temp after the IC would be useless to do that since the temp there is also largely dependant of vehicle speed and how to car was driven within the last minutes (heavy load ...light load)

[adamss24]

The v6 tdi engine has 1 intake temp. sensor wich is built into the MAF. There are a few more temp. sensors- the one behind the bumper hanging by the PAS cooler pipe and an inside temp. monitor wich is built into the climatronic fascia but them both are used to calculate the outside temp and they are no major reference to the ECU. Stefan is righ in saying the MAF integrated one is just there to measure air density and the car runs better after the battery due to the way the ECU adjusts itself. Drive it like you stole it for a few miles at the time including a trip on motorway with lots of revs and the car will choose the best settings for the engine. If you drive sedately it will be sluggish as the cars are built on a compromise between performance and ecconomy !

[blackwagon]

Since I am standing 45mins a day in traffic jams every day going to work the ECU adapts to this making the car react sluggish. I like a car that always reacts the same way, when I floor it it should go as fast as it can. I am considering installing a switch so I can cut the permanent + to the engine ECU when I press it. When pushed before starting it resets the learning values so the thing goes like it should. The succes of this method however depends on how quickly it adapts to the traffic jam driving.

I think there is also a temp sensor in the boost pressure sensor because you can also monitor the charge temp after the IC with VCDS, the only sensor that can provide this measurement is in my opinion the boost pressure sensor. This temp reads about 50-55°C under load in my car.

I got myself a tool to flash the ECU. Reading the ECU and saving the map works, writing however proves to be a problem.
I tried it once and it frightened the hell out of me. Erasing indicated 100% and the program froze on my laptop at 0% writing the new map.
Curiousely (and luckily) enough the car started and after checking the original file was still in the ECU.
I read somewhere that the fuse for the instrument cluster should be pulled when attempting to flash the engine ECU, however this was for the bEDC 15 in a Golf 4 or Bora. Does anyone have experience with flashing the 2.5 TDI EDC 15 ?
I have a tuning map with correct checksum.

B.R

Stefan

[fjtwelve]

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.

[blackwagon]

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

[fjtwelve]

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.

[swarcup]

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.

[blackwagon]

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.

[fjtwelve]

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?

[blackwagon]

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

[blackwagon]

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)

[fjtwelve]

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.

[fjtwelve]

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.