Hi,

I am please to be a member of the Audi owners group after purchasing my A4 Sline a few weeks ago. I have since been back and forth from the garage i bought it from with a weird noise that can only be described as a cross between a duck and a swosh! I've checked the "stowaway mallard sensor"! Yes i've heard quite a few of these jokes! At the moment i have no idea what it could be and neither do the garage, i've noticed a few people have had similar problems but didn't post if they had fixed it or not.

Does anyone have any ideas?? At the moment i have no ECS or ECL lights up, but can't check if its got any readings until my cheap e-bay code reader turns up.

Any help would be very much appreciated.

Audi A4 Sline 2005 1.8 Turbo Petrol.

Many Thanks

Els

 

what, if anything, are you doing in the car when you hear the noise? or does it just happen randomly? idling? under load? while shifting?

 

Doesn't happen on idle, just happens randomly under load. As in when in gear pulling away or cruising. People have said EGR valve needs cleaning or split hose some where. Any ideas?
Thanks for your reply

Els

 

I'm wondering if the previous owner replaced the diverter valve with a blow-off or hybrid. there should be a sticky around here somewhere that explains the diverter and the "closed loop turbo system". probably wouldn't happen randomly while cruising though. that is the kind of think I would think the garage would have sorted right away. Makes me think it might not be that.

Most of the other issues like the EGR or a split hose would usually trigger the CEL.

this is one of those things that is really hard to diagnose over the internet unless you have experienced that exact problem. hopefully one of the gurus will see your thread and chime in.

 

Thanks for your reply, it's defo not a whooosh noise like a boy racer turbo dump valve if that's what you mean. No light has come on but it doesn't mean there aren't any codes present. I'll have to wait for the reader to come. Either way I spoke to the garage and it's going back to All Audi Bristol to be repaired. Hopefully they'll find the source of the problem. Or like you say someone else may come across this thread who's had the same problem.

Thanks for your help anyway

Els

 

This most definitely sounds like a ruptured diverter valve.

 

Thanks for replying, Where abouts it the diverter valve located? if it is where i think it is i, also seem to get a slight sprays of oil in that area when accelerating hard in gear up to almost max revs.

Is it located about the EGR valve? A black circular disk on the top with a kind of funnel shape coming off it?

Many Thanks

Els

 

Ok so an update, after not replacing the diverter valve as instructed by you kind people, it appears to have got worst. To the point where acceleration is suffering issues to lagging and juddering! The engine management light flashes under acceleration and then goes off when taxi driving. Could this be that the diverter valve is completely destroyed rather that ruptured?

 

It could be. The flashing CEL means that you're having an active misfire. This is easy to believe. If the DV has failed, the fuel mixtures will be all wrong because air that the ECU expects to be in the cylinders isn't there (it's blowing back into the system from the failing diverter valves). Improper A/F mixtures will easily cause misfires. You'll have stored codes logged from the misfires, indicating which cylinder(s) misfired. That can help you track down the root cause of your issues.

 

sounds like a description of the PCV valve. if it is restricted, it might lead to your "duck" noise when it releases the pressure.

it looks kind of like this: