Car runs fine but by god loads of blue smoke..

SDHA4SLine

SDHA4SLine

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I know I know, loads of these threads already! however one difference for my issue is its constant blue smoke under load even though car runs fine and idles fine with no smoke. Doesn't matter if engine is cold, hot or in-between, warm weather or cold weather it just makes no difference. The smoke can be seen at night in people headlights and the day time.

Car in question is 2006 2.0tdi 170 BRD engine

New block and cylinder head aside the cars practically had all bolt on engine parts replaced (not all related but may as well give full picture of work done)...
Parts replaced.
Both n75 's
MAP senser
MAF sensor
EGR valve (egr restrictor gasket in place also)
coolant temp sensor
fuel temp sensor
fuel filter
air filter
Inlet manifold actuator.
Turbocharger
Injectors replaced under recall
Egr cooler
Clutch and flywheel

Also...
Oil pump/balance shaft modification done
Anti judder valve & inlet manifold removed, checked and cleaned.
Terra clean and terra clean EGR treatment done.
Timing checked twice and both occasions ok although noted torsional value was out by 1.85 degrees which is apparently within tolerance (+/-5 deg) or so I'm told.
Dpf has been checked and ok

Any suggestions of what to investigate regarding causes of blue smoke would be appreciated? Was planning to get remap and dpf delete but really want this sorted before I do that.

Doesnt seem to be losing any coolant and very little oil use (admittedly I've not monitored this very closely though)

Regards
Steve
 
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Blue smoke is usually oil related. Have you had a compression test done ?.
The torsional value for the timing I am sure is more like + - 3 degrees and it does make quite a difference to the running getting it close to 0. I used to run my Passat around +0.5 degree.
If the timing was 5 degrees out on a 1.9 it would probably struggle to start.
Have you checked crankcase ventilation as well. If the crankcase gets pressurised oil will get pushed passed the seals in the turbo.
Take the oil filler cap off the engine when it's running and see if theres much pressure in there.

Karl.
 
Thanks Karl, if there is pressure in there should I expect to hear a kind of whoosh sound?

Is it safe to rev the engine a little with filler cap off to see if any smoke or oil vapour is being pushed out or would this be normal expected behaviour?
 
audi upgrades
Just hold your hand an inch above the filler neck and see if there is any back pressure,i wouldnt rev it though as you will have drops of oil flyin everywere
 
I've just been down to Audi Birmingham during my lunch break, they had a tech look at it (possible crankcase breather problem) he said it seems fine. His explanation for diagnosis is when filler cap is removed a small amount of blue smoke out of top is acceptable/normal, also he said the fact there was no resistance/vacuum making the filler cap hard to pull off when running shows no sign of breather problems and also said that when you just place the filler cap back over hole (not secured in place) it bounces around with pressure escaping which is what should happen.

had taken a video but cant work out how to attach as keep getting url error or something

Edit: Karl, no I haven't had compression test done can it be done via vcds? thinking of putting a call on here for help if it is possible.
 
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stevo71 said:
Just hold your hand an inch above the filler neck and see if there is any back pressure,i wouldnt rev it though as you will have drops of oil flyin everywere
Click to expand...

Yeah I could definitely feel small pulses of air blowing against my hand when doing this, is that a bad sign considering what the Audi tech mentioned about filler cap being placed over hole and bouncing around being a good sign?


Edit:
Just thinking of what I've said above, would a blocked crankcase breather cause a vacuum in cylinder head or positive pressure blowing out?
Or to put it another way if there was no issues and I placed my hand over the filler cap hole should it be sucked down or blown away or neither just normal atmospheric pressure?
 
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Have you had a diesel before? Only asking and hoping to not sound cheeky but they do smoke and always look far worse in the rear view with headlights than they actually are, you're may be worrying over nothing??
 
Yes last two were deisels driving same route for four years and nothing from the other two that I noticed. it's puffing clouds in the daylight too took audi tech out today as he was saying the same as you and many others. That was before he witnessed it himself. He agrees it's more than should be expected. Just glad it's not black stuff
 
Could just be over fueling with this cold spell, as you've changed the CTS(OEM?) I'd be possibly thinking thermostat, does it sit at 90 ok on the temp gauge?

Or a boost hose leak can also cause excessive smoke

Did Audi scan it?
 
Sounds like the crankcase breather is OK. What you describe is the kind of thing I would expect. If a breather is blocked you can get so much pressure in the crankcase that it will blow the oil filler cap off. Happened to a friend of mine with a 2.0 petrol vectra.
The oil flow back to the sump from the turbo should be free, If the oil level is high or there is excessive pressure in the crankcase this causes excessive pressure in the turbo bearing and the oil seals will weep oil causing blue smoke.
why did it have a new block and cylinder head ?
 
No scan just took a quick look free of charge for me.

Yeah cts was genuine audi/vw part. Yes temp steady as a rock once it reaches 90.

For the uneducated (me) why would a faulty thermostat cause smoking? Seen this on many other threads just not been able to understand why this would have that sort of effect.

Had boost checks done via vcds at audi dealer would it show up a leak or just required vs actual boost?
 
desertstorm said:
Sounds like the crankcase breather is OK. What you describe is the kind of thing I would expect. If a breather is blocked you can get so much pressure in the crankcase that it will blow the oil filler cap off. Happened to a friend of mine with a 2.0 petrol vectra.
The oil flow back to the sump from the turbo should be free, If the oil level is high or there is excessive pressure in the crankcase this causes excessive pressure in the turbo bearing and the oil seals will weep oil causing blue smoke.
why did it have a new block and cylinder head ?
Click to expand...

It didn't have new block or head, sorry I can see the way I typed post may be misunderstood. What I meant to say was they are practically the only things left to look at/change.
 
But not leaving it 20k between changes mind you, 10k max. It's had 4 oil and filter changes since last July due to it being required for various work carried out on the car
 
SDHA4SLine said:
No scan just took a quick look free of charge for me.

Yeah cts was genuine audi/vw part. Yes temp steady as a rock once it reaches 90.

For the uneducated (me) why would a faulty thermostat cause smoking? Seen this on many other threads just not been able to understand why this would have that sort of effect.

Had boost checks done via vcds at audi dealer would it show up a leak or just required vs actual boost?
Click to expand...

If it's stuck open in this weather it will over cool the engine as it'll be diverting water through the radiator instead of retaining the water around the block until it's warm. As it's cooler the engine will use more fuel so more smoke, in extreme cases the the car will dump so much fuel in that it can't burn off so it literally fires unburnt diesel vapour out the exhaust. Commonly mistaken for white smoke and can smell of diesel but as you're not getting smoke at idle and only under load I very much doubt this is your problem.
Just read it's blue smoke so unlikely to be a boost leak, they usually give you black smoke so again unlikely.
Karl could be right with the turbo oil seals, did they replace the oil return pipe when they changed it?
 
audi upgrades
ajax1976 said:
If it's stuck open in this weather it will over cool the engine as it'll be diverting water through the radiator instead of retaining the water around the block until it's warm. As it's cooler the engine will use more fuel so more smoke, in extreme cases the the car will dump so much fuel in that it can't burn off so it literally fires unburnt diesel vapour out the exhaust. Commonly mistaken for white smoke and can smell of diesel but as you're not getting smoke at idle and only under load I very much doubt this is your problem.
Just read it's blue smoke so unlikely to be a boost leak, they usually give you black smoke so again unlikely.
Karl could be right with the turbo oil seals, did they replace the oil return pipe when they changed it?
Click to expand...
Ah, that makes sense thanks for the explanation :thumbs up:
Well I imagine a new thermostat is a cheap item so this may well be worth doing just to cross it off the list. Coolant not been changed for years so would be a good excuse to change that out.

No oil return pipe fitted ( I would really like to think that midland VW ) would have at least checked it was nice and clear. New oil feed pipe was fitted though.
 
If return pipe is blocked this can restrict the flow out of the turbo leading to pressure in the turbo. This will force oil out the seals giving similar symptoms to what you have.
 
Just rang midland vw to check & they reassured me the return pipe was removed and checked.

How often should coolant (pink G13 stuff) be changed? Its been 3 years since it was last changed on my car, if it is past its sell by date then I may just as well get it changed & have thermostat done at same time.

Been quoted £100 to £110 all in to do this does that sound reasonable? They said 1 hour labour plus G13 coolant, Genuine Thermostat & thermostat seal?

Edit, is there a way to test thermostat in place or is it a mechanical working or not working thing? Could it be checked via vcds?
 
Sounds an ok price tbh, I'd be tempted to pay that to keep my hands clean but not a hard job a do yourself.

Not sure tbh, only know the old school way of removing it and dumping it in hot water to test, hardly worth the hassle for the cost of a new one.
 
you must have deep pockets mate to keep forking out on you A4, i bet you've trown a fair bit of cash at it so far:eek:, keep up the good work now though as it will all be worth it in the end,;) :)
 
You wouldn't believe (or maybe you would actually) how much, it's only because I have a spreadsheet I know how much and it's shocking.

For all the issues and moaning, I do still really like it. For the money I paid to buy it and what's been forked out on repairs etc I could easily have bought a b8 but I genuinely prefer b7's. I just want to get all the grease monkey work done before I get all my new exterior body work stuff done.

This (smoking) is the last thing I need to sort before remap then it's off to bodyshop for 1st of what I imagine will be many visits.

Thanks to people like you and your mods I got the modifying fever really bad now...
 
And as for deep pockets, I don't now, I've just got impatient and slammed a load on c/card! Have 2 years interest free to pay it off thank god
 
ah yes , the good old flexible friend;), when i use plastic for anything with wheels on and the wife knows about it, i just quote her this " i'm living for today and sod tommorow" .:D
good luck with it:)
 
Cheers, I will get it sorted even if it kills (bankrupts) me!
 
Right new thermostat fitted and full coolant flush and change done today. Let you know after a few days if it improves, if not it's nice to know it's finally got nice fresh coolant in there.
 
Right to update I need to eat humble pie or things are actually getting weirder...

Now I'm actually getting to drive in full day light at warmer temps (8 to 10 degs) the smoke is definately or has turned to grey. Still lots of it cold engine or hot engine but only under load. Strange thing is the miles to empty (after filling up) and actual miles to tank have increased, massively by about 80 to each full tank. Still driving the same so not down to that I'm sure. Any ideas or is it simply DPF on way out ?
 
How many miles do you do on each trip? Might just need an Italian tune up, also where do you buy your fuel from?
 
I think I have same issue on my A4 B7 Avant 2.0TDi Multitronic. It also spits out small amount of grey smoke on startup. It has EGR deleted. I noticed this thing when I was buying the car, I ran full diagnostic, but everything was fine, so I bought the car instead. I also changed the termostat, since it had issues when driving cold in the motorway, never reached 90 degrees, so It was minor issue, not smoke related.
Anyway I'm driving it every day and don't bother about that. Car runs perfectly and it's just grey smoke on load. It's diesel, what can you expect ?
I bought my B7 cabriolet, same engine 2.0TDi 103 kW 8V, just manual. And this baby NEVER releases ANY smoke. You can floor it or whatever, the exhaust pipe is clean like in would be petrol :)
 
Burnzybubbles said:
How many miles do you do on each trip? Might just need an Italian tune up, also where do you buy your fuel from?
Click to expand...
75 miles a day on motorway and I don't hang about. Once a week 4th gear about 3k revs set cruise on for about 15 miles which I hope would be enough to keep things clear. Every day, ( once car is up to temp) the car gets its italian tune for couple of minutes whilst getting up to speed a couple of times. Hardly any of the milage is town driving.
 
Another thing is do you use supermarket fuel? hence me asking in my last post as supermarket fuel can cause unnecessary smoke due to its poorer quality.

But yea it's deffinately not a case of not being used then, if it's starting to clear then you might find its taking a while to burn off, my 3.0tdi is a bit smokey, it was really bad when I first drove it but I sooned burned most of it off, mine I think is just a dirty inlet tract, when the weather gets better I'll clean all the EGR and pipework from MAF too inlet manifold, this weekend I'm going to run some liqui moly diesel purge through it see if I can remove some carbon in the combustion chambers but I'm a bit doubtful as like yourself I don't hang around, worst case is it'll remove any gunk in the injectors or around the HP side of the fuel system.
 
Since I've owned it only shell v max has been in it, had inlet manifold off and cleaned, EGR replaced for brand new one, MAF map etc all replaced for new audi OEM. I begining to think I'm going to have to live with it even though it's a diesel I dont think it should be this smokey.
 
Fingers crossed today's effort wil sort this.....

New Cam belt, water pump and resetting injector clearances/lash.
 
Can't see how a water pump and cam belt will cure the smoke but injectors maybe. Fitting the EGR restrictor will let more exhaust gasses straight out of the exhaust pipe, hence more black smoke. Also if the car is mapped you will get more smoke, don't know if you are. All in all it is a DERV and you can't expect nil smoke like a petrol motor.
Check out my old Fabia, it's the older 1.9PD engine and 205 bhp. and that's a healthy engine believe it or not.
 
Water pump just a side because timing belt being changed. Hoping the fact the torsional value was a couple of degrees out may help.

No not mapped
 
yes I totally understand it will always have some smoke but mine can't be right it's always leaving a cloud of smoke behind that's just embarrising. Was hoping now we have nice warm weather it wouldn't look too bad but still the same. I'm always keeping an eye out for other vw/audi 2.0tdi's on my motorway commute and never notice any that leave a comical James bond style cloud behind them. Only ever see fords and white van man that do, but theirs is always black smoke
 
See what you mean there, our A3 doesn't throw out blue smoke after running a few minutes, black smoke happens only on brisk acceleration. It's because of the expense of running TDI's I'm moving away from DERVs, just one thing after another and always expensive. Even some Councils are demonising DERV's now saying it's the devils fuel.
Petrol engines are still relatively simple and quite efficient these days.
 
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