EGR Valve

[rscrambler]

Hi, new on here and am hoping someone can help.
After owning a A3 S Line tdi for 6 months and really liking it i decided i wanted a bit more space so i bought a A4 S Line TDI Quattro (A3 still for sale if anyone is interested).
Picked up car friday evening,run it for the weekend and found the engine to be a bit sluggish. MPG is bad, at best about 33mpg, and while driving along yesterday felt a slight hesitation and the GLOW PLUG warning light come on. Turned engine of and turned it back on again, light had gone off. Anyway, got to where i was going, opened the really hot bonnet to be greeted with smoke coming out of the drivers side of the engine.
Anyway rung up dealer and told him to come and pick it up.
Could this be anything to do with the EGR Valve, or does anyone else have anymore opinions on it, i want to be fully armed when i go back to dealer and he tries to fob me off!!
Many thanks for any help recieved.

 

[mrose]

Hi, new on here and am hoping someone can help.
After owning a A3 S Line tdi for 6 months and really liking it i decided i wanted a bit more space so i bought a A4 S Line TDI Quattro (A3 still for sale if anyone is interested).
Picked up car friday evening,run it for the weekend and found the engine to be a bit sluggish. MPG is bad, at best about 33mpg, and while driving along yesterday felt a slight hesitation and the GLOW PLUG warning light come on. Turned engine of and turned it back on again, light had gone off. Anyway, got to where i was going, opened the really hot bonnet to be greeted with smoke coming out of the drivers side of the engine.
Anyway rung up dealer and told him to come and pick it up.
Could this be anything to do with the EGR Valve, or does anyone else have anymore opinions on it, i want to be fully armed when i go back to dealer and he tries to fob me off!!
Many thanks for any help recieved.

DPF most likely. Glow plug light comes on when the DPF soot loading exceeds certain limits. The DPF is regenerated by buring off the soot. There are two main ways it does this; passive (where the DPF is regenerated by normal driving on longer higer rev journeys like motorway drives) and active (the DPF soot loading reaches 45% and the ECU calls for a regen. The ECU closes the EGR and increases the injection timing to raise the DPF to sufficient temperatures to burn off the soot).

Heavy soot loading could be the cause of the sluggish performance and it is possible you poped the bonnet during an active regen. Not sure you would normally see smoke though. The DPF does reach 600 degrees C during an active regen. The book tells you not to park over dry grass or anything combustible during an active regen! Did you notice the exhaust sounding pretty loud when you paked up and was the fan running hard when you poped the bonnet open?

What sort of driving were you doing over the weekend? Lots of short hops? Is it a new car approved used or maybe a demonstrator? Could be it has done quite a few short test drives at the dealership in the last few weeks which may have loaded the DPF. A forced regen at the dealer should sort it out.

Hopefully the dealer will sort it out for you if it turns out to be anything else.

 

[mrose]

Oops. Welcome new dude! Manners is not my strong suite ;-)

 

[S.line]

Sounds like the regen has started. Nothing major (we hope) welcome to forum, any pics of your new toy?

 

[mrose]

Yep, I reckon you just interrupted the regen. The awful mpg is probably the fuel lost to the regen cycle. Let us know the upshot from the dealer. If you're still suspicious after you get it back post in the VCDS forum to see if someone local could do a fault scan for you. There are a lot of friendly and helpful folk here.

 

[rscrambler]

Thanks for the welcome people, much appreciated.

Could this process take all weekend though because the mpg has been bad since i picked it up friday evening.

I was doing decent trips over the weekend and i do like to get going but i don't know how the previous owner drove it. My A3, which is still for sale if anyone is interested, gets a good blast up and down the A1 every day and i've not had this happen to me while driving that, but i've only had 6 months.

No pics yet, not had it long enough!! Its just a lovely looking clean standard car.

Another question, were there different standards of Bose systems for these because the one in the A3 seems a lot better ie louder.

 

[rscrambler]

Sorry for being a bore about this but i'm still a bit worried about my car. I would love to know what other people are getting mpg wise out of there 2007 A4 TDI S Line QUATTRO estate's, it must be better than my 33mpg. It looks like i'll get no more than 450 miles out of a tank full, or is this all i should be expecting??

Another thing that still concerns me is the warning light i had, that should go into the memory so as it can be traced and remedied, but the dealer i bought it from couldn't find the fault and i assume the only way of getting rid it is to delete it manually after it has been fixed????

Its a lovely car but if bits not running properly he can have it back.

Any advice very much appreciated.

 

[Jay.Ing]

Suppose the only way your going to know is either by getting VCDS on it, or take it to an independent garage, get an assessment there, and if there is anything wrong take it back to where you bought it from with proof and get the money back you spent at the other garage!? Thats if you have already given the dealer a chance!

 

[rscrambler]

Suppose the only way your going to know is either by getting VCDS on it, or take it to an independent garage, get an assessment there, and if there is anything wrong take it back to where you bought it from with proof and get the money back you spent at the other garage!? Thats if you have already given the dealer a chance!

Because i like the car i feel like i'm giving the dealer to many chances.
Did take it to another garage and he said he could not find the fault. He said it should still be there, if its not how can anyone fix the problem, which makes me wonder!!

 

[mrose]

Hi rscrambler,

How old is the car and what mileage is on it? Engine size and BHP/PS? Manual or Auto? Without those details it's hard to compare with other owners MPG.

I get 44 - 47 mpg combined on 2.0 140hp/143ps FWD Manual box. That's not great compared to official fantasy figures given by Audi but quite normal for real world driving (some would say quite good).

Above 2.0 140hp/143ps 4WD Auto box will return very different consumption figures. There are a lot of threads where folk quote their figures and usually a 4WD higher powered engine with Auto transmission seems to return quite low economy figures in the A4.

 

[rscrambler]

Hi rscrambler,

How old is the car and what mileage is on it? Engine size and BHP/PS? Manual or Auto? Without those details it's hard to compare with other owners MPG.

I get 44 - 47 mpg combined on 2.0 140hp/143ps FWD Manual box. That's not great compared to official fantasy figures given by Audi but quite normal for real world driving (some would say quite good).

Above 2.0 140hp/143ps 4WD Auto box will return very different consumption figures. There are a lot of threads where folk quote their figures and usually a 4WD higher powered engine with Auto transmission seems to return quite low economy figures in the A4.

Hi, that would help wouldn't it, its a 2007 2.0L TDI 4wd 170 quattro estate. I've just talking to someone and they say they can get 530-600 miles on a tank, depending on how he drives it. I'm only going to get about 450 at the very best.

 

[mrose]

Thinking about it some more - and this depends on your engine but where you saw smoke coming from in the engine bay is probably where your DPF is. Mine is certainly there but I have a CAGA engine. It's likely to the left of the Engine block lower down and behind the exhaust manifold. If you peer in you should be able to see it quite easily; it's a fat pipe with tapered ends front and rear with a couple of sensors one end and and a single sensor the other end. This does get very hot but I'm not so sure you would see smoke from it unless there has been some oil or other combustable fluid spilled on it or something. Problems with the exhaust system will hit economy quite hard but a proper diagnostic would find something if there was a problem.

Ideally the dealer wouldn't just be looking for DTC codes but would be looking at measuring block values for the exhaust system, pressure, soot loading etc. Could be someone has monkeyed around with the DPF and there is a bad or missing gasket and a leak hence the smoke getting into the bay. You could visually inspect the DPF for signs of tampering - it could be unusually clean compared to the rest of the engine or the bolts could be slightly scarred or show signs of recent tooling. An entire industry has grown up over the last 10 years deleting and gutting DPS and mapping them out, however, you'd see better torque and MPG and no faults if that had been done properly. As Jay.Ing says your best bet is to get VCDS on it.

Or it's all perfectly normal and 33mpg will improve as you get used to cars performance style. One thing I would say an A4 Quattro is a lot heavier than your previous car and the low end torque is not great on the TDIs with DPF so the sluggishness may be all down to that. It's not running ragged or anything. The only worry was the hesitation you noticed. Is it doing that still?

 

[rscrambler]

The smoke was coming from the area of the engine were the DPF is and i would say, considering i'd just bought it, is the dealer could have given the engine by a bit of clean and it was just a bit of residue solvent or something.
It definantly takes a bit more to get it moving but as you say it is a heavier car than the A3, I'm just a bit concerned as to where the code gas gone because if the fault is still there, well who knows......
Time to find out more about a local VCDS to me.

 

[mrose]

Hi, that would help wouldn't it, its a 2007 2.0L TDI 4wd 170 quattro estate. I've just talking to someone and they say they can get 530-600 miles on a tank, depending on how he drives it. I'm only going to get about 450 at the very best.

That would make it a B7 not a B8?

 

[mrose]

Post in the VCDS section for someone local to do a full scan. The sooner you get VCDS on it the better. Remember the glow plug lights flashing generally indicate a problem - could be anything from injectors to turbo having a hiccup. Common issues are exhaust gas temp sensor etc. Most of these would throw a code in the ECU.

Smoke coming from near the DPF is also smoke coming from near the turbo. Loss of power could be linked there too.

Start pressuring the dealer with this info now. Tell him you're concerned the engine and/or exhaust system has an intermittent fault and you know that smoke coming from the engine bay around the DPF and turbo are not expected behaviour and together with the hesitation and lack of power are a bit of a serious concern.

I'm not trying to worry you just advising you to lay it on a bit thick with the dealer in advance till you get to the bottom of it ;-)

If something does go bang they can't say you didn't warn them.

 

[rscrambler]

Post in the VCDS section for someone local to do a full scan. The sooner you get VCDS on it the better. Remember the glow plug lights flashing generally indicate a problem - could be anything from injectors to turbo having a hiccup. Common issues are exhaust gas temp sensor etc. Most of these would throw a code in the ECU.

Smoke coming from near the DPF is also smoke coming from near the turbo. Loss of power could be linked there too.



Start pressuring the dealer with this info now. Tell him you're concerned the engine and/or exhaust system has an intermittent fault and you know that smoke coming from the engine bay around the DPF and turbo are not expected behaviour and together with the hesitation and lack of power are a bit of a serious concern.

I'm not trying to worry you just advising you to lay it on a bit thick with the dealer in advance till you get to the bottom of it ;-)

If something does go bang they can't say you didn't warn them.

Of course you are right and I will get on it straight away. They know I have concerns mad I will keep the pressure on this weekend.

 

[rscrambler]

Just to let you know I've taken car back and got my money. Couldn't relax with it, playing on my mind all the time so there you go. A shame really as a lovely looking car, just got to find another one now, just missed a nice one this morning and saw another one which was a bit of a nail for 10k, can't believe what some dealers will put on there forecourt.