Does this sound like a leak or a failing turbo?

[danb986]

After getting to the bottom of my losing water problem (turned out the rad was visibly leaking, luckily) I've now got a new problem;

I've started getting quite a bit of white/grey smoke that smells like diesel fumes. This happens randomly.

- Sometimes it smokes a lot on start up, sometimes it starts without so much as a waft of smoke.

- It doesn't matter if it's hot or cold.

- It's at it's worst when pulling away in 1st gear. In fact, when driving it hard in the higher gears it hardly seems to smoke at all.

- I'm not losing any water or oil.

- Besides the smoke, the car runs perfectly and I haven't noticed any loss of power.

- VCDS doesn't pick up any fault codes.


While Audi were changing the radiator about 500 miles ago, I also got an oil change service done. I then bought the air filter and diesel filter from them and fitted those myself, so all the filters are new and genuine.
(They also gave me a free sump after striping the thread, but that's another story).

I did notice the boost pipes under the front drivers side of the engine bay are oily at the joints, but Audi didn't seem concerned about this.

Do these symptoms sound like a boost or vacuum leak, or do they sound like the turbo is on it's way out?
If it was the turbo, then wouldn't it happen more at higher revs and full boost, rather than when pulling away normally in 1st gear?
Does the engine twist more when pulling away in 1st gear, because I'm wondering if it's opening up a split pipe or joint under these conditions?

I'm baffled, please can anyone offer any advice?

 

[danb986]

While going through hundreds of search results I came across a similar problem people have been having with the A6 2.5 TDi. The conclusions they came to were either a blocked breather (I've not got the pressure when removing the filler cap) or a crudded up and sticking EGR.

I know sort of know how an EGR works, but I'm not sure of the times it would be open/closed in relation to my smoking issue. Also, how does a stuck EGR cause white smoke?

 

[Ash187]

In first instance I would say check the joints in the boost pipes as the oil is a sign of an air leak, not sure about the egr but I would also like to know the answer to that one as I sometimes feel a little under power in mine although I recently changed the boost and intercooler pipe.

 

[Av4nt]

Im not sure how exactly it causes white smoke...but a stuck EGR valve will chuck some utter crap out the back. could well be that yours is sticking either way if its intermittent. My egr valve snapped off and lodged itself in the egr unit luckily and not in the pipes, but when you hit the gas it just leaves the road behind in a dense fog lol!

Have it cleaned it may well be the issue

 

[danb986]

When you say yours left the road behind in a dense fog Av4nt, what colour was the smoke?

I've also just noticed that my oil level was a bit over the maximum mark, even though it was Audi that did the oil change. I wonder of that is making matters worse.

I've noticed that mine only really smokes when pulling away up to 1500rpm and then it's clear.

 

[Jord]

Definetly worth cleaning the egr out ago with shudder valve which is attached, te leaking boost pipe are common, don't bother buying new seals off Audi, will cost you £12 for nothing, just get some ptfe tape and pack the washer, I've done this on mine, doesn't leak abit

 

[danb986]

Definetly worth cleaning the egr out ago with shudder valve which is attached, te leaking boost pipe are common, don't bother buying new seals off Audi, will cost you £12 for nothing, just get some ptfe tape and pack the washer, I've done this on mine, doesn't leak abit

Thanks for the advice Jord. I'll just get the ones for the egr then.