stifster

Gday.

Just wondering if anyone can have a quick scan of my injector readings. I have a sporadic grey smoke issue (seems to only happen every few weeks), where the car just blows a stack of grey smoke with any acceleration, then goes back to normal after stopping for an hour or so.

Not getting any obvious issues in the scans, and the car is running fine (no performance issues), although I am getting ****ty mileage, but have only just started driving it in the city - so not sure what is normal. Not losing water or oil.

Address 01: Engine (4F9 910 401 L)

13:10:33
-4.0∞KW Injection Start (specified)
0.22 ms Injection Duration (specified)
0.80 mg/str Injection Quantity Deviation Cyl. 1
0.38 mg/str Injection Quantity Deviation Cyl. 2
-0.33 mg/str Injection Quantity Deviation Cyl. 3
-0.52 mg/str Injection Quantity Deviation Cyl. 4
-0.14 mg/str Injection Quantity Deviation Cyl. 5
-0.14 mg/str Injection Quantity Deviation Cyl. 6

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 01: Engine (4F9 910 401 L)

13:18:27
-4.0∞KW Injection Start (specified)
0.22 ms Injection Duration (specified)
0.61 mg/str Injection Quantity Deviation Cyl. 1
0.19 mg/str Injection Quantity Deviation Cyl. 2
-0.19 mg/str Injection Quantity Deviation Cyl. 3
-0.61 mg/str Injection Quantity Deviation Cyl. 4
-0.05 mg/str Injection Quantity Deviation Cyl. 5
0.05 mg/str Injection Quantity Deviation Cyl. 6

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 01: Engine (4F9 910 401 L)

13:18:30
-4.0∞KW Injection Start (specified)
0.26 ms Injection Duration (specified)
0.56 mg/str Injection Quantity Deviation Cyl. 1
0.19 mg/str Injection Quantity Deviation Cyl. 2
-0.19 mg/str Injection Quantity Deviation Cyl. 3
-0.61 mg/str Injection Quantity Deviation Cyl. 4
0.00 mg/str Injection Quantity Deviation Cyl. 5
0.05 mg/str Injection Quantity Deviation Cyl. 6

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 01: Engine (4F9 910 401 L)

13:18:32
-4.0∞KW Injection Start (specified)
0.24 ms Injection Duration (specified)
0.56 mg/str Injection Quantity Deviation Cyl. 1
0.19 mg/str Injection Quantity Deviation Cyl. 2
-0.19 mg/str Injection Quantity Deviation Cyl. 3
-0.61 mg/str Injection Quantity Deviation Cyl. 4
0.00 mg/str Injection Quantity Deviation Cyl. 5
0.05 mg/str Injection Quantity Deviation Cyl. 6

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 01: Engine (4F9 910 401 L)

13:18:32
-4.0∞KW Injection Start (specified)
0.24 ms Injection Duration (specified)
0.56 mg/str Injection Quantity Deviation Cyl. 1
0.19 mg/str Injection Quantity Deviation Cyl. 2
-0.19 mg/str Injection Quantity Deviation Cyl. 3
-0.61 mg/str Injection Quantity Deviation Cyl. 4
0.00 mg/str Injection Quantity Deviation Cyl. 5
0.05 mg/str Injection Quantity Deviation Cyl. 6

stifster

Just following up on this (I guess most of the problems I post are beyond the knowledge of other forum members, given the responses I get - so I'll add any info or steps to help others as best I can).

I added some injector cleaning fluid to the tank each time I get a smoking issue. Not sure if it has any effect, but the smoke stops for a while afterwards (given that it's not been present after each time I've added - even immediately - I'm sceptical that it may be a false positive, given that it may just be the cycle the car was in that is somehow changed when it's driven again).
Another unusual and purely anecdotal coincidence is that the smoke only seems to occur when it's been raining. No idea why that would be a factor - I've just noticed that that's been the case 100% of the time.

Anyone got any info or advice on the measurements above. Anyone?

stifster

Still having this issue sporadically.

I was able to reproduce it twice in the same situation - that being:
Was idling in traffic at the bottom of a hill (same spot on Punt Road)- I got the sweet smell in the cabin when I started accelerating up the hill, and the white smoke billowing out of the exhaust.
IN both situations, I pulled over and switched off the ignition, waiting for 5 minutes, then proceeded without any smoke.

There is no other symptoms (surging/loss of power/knocking, etc).

Could it be a stuck or over advanced injector?

stifster

Love having these conversations with myself - but you never know, it may help someone else.

Finally pulled an error code today that possibly explains the occasional white smoke issue.

EGR System p0401 - Insufficient flow (intermittent)

I did see a mechanic and they thought it may need a new cooler - which is quite expensive to fix (this was before the error code appeared - they thought the cooler might be cracked and leaking coolant into the exhaust - I'm not losing any coolant and have been monitoring it for the past 4 months and haven't had to add any).

Just wondering if anyone has an idea of how much work there is in cleaning the valve and cooler and if that could possibly be the fix for the white smoke?

stifster

I investigated the mechanical option of pulling out and replacing the EGR - mechanic said it would be $4.5K. Bzzt.
I thought I'd buy some time by remapping and deleting the EGR which I can get done for $495.
I shopped around and had a chat to a bloke who suggested it wasn't a good idea without first cleaning it. He offered to do it with a product (didn't indicate which), that they hook up and then leave the car running to burn it out ($395), then take a longish drive.
i'm sceptical - but don't really have any other options.

stifster

Another update - and hopefully the solution.
Before I was to undertake a remap and EGR delete, I was advised to run a product through the EGR to clean it prior.
I took the car to a guy who rigs up the product and then runs the car while it burns it out: "Diesel tune EGR induction system clean"
He also ran 2 x DPF filter cleaner through as well.
Not sure what products he used, the invoice refers to "Ultimate Diesel" but that could be any number of brands.
All up $480AUD

Anyway - I performed a regen on the DPF the next day - and so far have had no smoke whatsoever on a number of short drives. Fingers crossed.

stifster

Just a post-script here.
The above only lasted a few weeks and back to blowing smoke. It eventually went into limp mode.
I took it to a reputable Audi mechanic (German Technik here in Melbourne) and they replaced the EGR Valve and EGR Cooler, and chemically cleaned the DPF. It's a tricky job and it wasn't cheap - but it's totally fixed the problem (I had this done over a year ago and it's completely sorted still).
Basically, you're looking at ~$3500 (labour and parts) to not get your hands dirty.

A6 4.2 Vier

Thanks for your posts and following up with the solution.

I don't mind paying a mechanic who can properly diagnose the problem and solve it without replacing needless parts.