Purge canister valve fault and cylinder 4 misfire fault

ukrainian

Member
The A2 is certainly not dull. There is always something :p. Check engine light came on last week, but no other symptoms. VCDS-Lite that night told me it was this:

16825 - EVAP Emission Control Sys: Incorrect Flow
P0441 - 35-10 - - - Intermittent
Ross-Tech page is quite helpful on this http://wiki.ross-tech.com/wiki/index.php/16825/P0441/001089

Car was going in to garage next day for routine checks anyway, before our road trip to France at the end of July. My friendly mechanic said just get a replacement purge valve and fit it yourself. However a couple of days later and before I got hold of a replacement part, check engine light comes on again, this time flashing, and the car is in limp home mode - the 4th cylinder is shut down. The EVAP flow fault code is back, but also a new one -

16688 - Cylinder 4: Misfire Detected
P0304 - 35-00 - -
http://wiki.ross-tech.com/wiki/index.php/16688/P0304/000772

Ross-Tech page points to the purge valve as one of the possible causes, so there is hope it's a simple fix. But the part is not on the shelves anywhere, MK Audi quoted 3 days delivery (and cut me off before they could tell me the price!). There is no VAG part number on it, only a Bosch part number which is 0 280 142 345. Available on ebay/Amazon at £40-50 but no next day delivery option. Anyway it's back in the garage tomorrow where I hope my friendly mechanic can get hold of a replacement same day. I will report what happens.
 

ukrainian

Member
Thanks, it may be my next move if it can't be sorted tomorrow. The link didn't work for me though, whether I click on it or copy and paste it I end up on generic /car-parts page. I also tried searching for 0280142345 on ECP and I get a "sorry nothing found" message. Weird..
 

ukrainian

Member
The news from the garage is that the two faults are unrelated, despite being so close in time to each other, and despite the second (chronologically) fault's description listing the first one as a possible cause. In other words a coincidence. Apparently cylinder 4 coil pack is as dead as a dodo. Changing the other three coil packs at the same time as a precaution.. And the purge canister valve, too, when that arrives. Hopefully no more surprises now.

Some niggling doubts remain - could there be something still undiscovered that links the two faults. Or perhaps the purge valve failure lead to the coil pack failure? Just thinking - the old A80 had just the one coil for all 4 cylinders, so working 4 times as hard, and was still the original one at 170k miles and 24 years old.. Or are they just cheap and nasty these days. My friendly mechanic seems to think it's just age-related.
 

ukrainian

Member
Further developments. Car now has 4 brand new coilpacks and is running fine. The "EVAP Emission Control Sys: Incorrect Flow" fault has now vanished. It had been coming back after clearing, but in doesn't any more. I did manhandle the Bosch purge valve whilst trying to make out the part number, perhaps it was a dodgy connection at the valve.

However, as I drove off from the garage, the battery light on the dasboard took a long time to go out... topic for a new thread :rolleyes:
 

ukrainian

Member
An update. Although the replacement Bosch purge valve arrived back in July, there was no urgency to fit it as the fault code stopped reappearing. Now having been to the south of France and back, the original "EVAP Emission Control Sys: Incorrect Flow - intermittent" fault is back (no warning on dash though). Looks like the two fault codes showing up just days apart was really a coincidence and nothing more.
 
Apparently cylinder 4 coil pack is as dead as a dodo. Changing the other three coil packs at the same time as a precaution.

Just thinking - the old A80 had just the one coil for all 4 cylinders, so working 4 times as hard, and was still the original one at 170k miles and 24 years old.. Or are they just cheap and nasty these days.


Nail on head!

Our B4 80 2.6 of almost 20 years now has been the most amazingly reliable car ever along with the C4 100/A6.

Glad your getting somewhere with your A2, they are intoxicating cars and despite the fragility of the A2 i still like to drive it. :)
 

PlasticMac

Member
@ukrainian
Can you describe the tank vent, cannister, N80 solenoid circuit? Where does the cannister outlet vent to, and when does the N80 open and close?
Any info very much appreciated.
See this new thread also:
Mac.
 

ukrainian

Member
I don't understand in great detail how the evaporative emission system is supposed to work and how it might affect an FSI (mine's the simple 1.4L petrol BBY). In my case there was no obvious symptoms like hesitation, just the fault code and the check engine light. It seems that the engine management system decides somehow whether to just log the fault or to illuminate the check engine light as well. Even when the light came on I didn't notice any performance issues. I suppose the symptoms will depend on how the valve fails - stuck open or stuck closed. The fault code does not tell us which.
 
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