tester123

Ok, the Womp womp or duck sound -whatever you call it, doesn't seem to go away (check Fuel Bank 1 & 2... thread in my Sig.). I thought I had this figured out before but my assumptions were wrong.

Formally, I think it is called Crankcase Breather valve. I understand the concept of venting blow-by gases into intake rather than outside. What I don't get is WHY it makes those F**KING sounds? (ahem).. why it is quacking like a strangled duck?

It seems to take in air from outside (or vent?)... hence the sound? Anyway, the original part's insides were crumbled so I replaced with an aftermarket from Amazon.com of all the sources! -it was cheapest there. Dealer wants over $100 for this... I don't want to buy it if there is an issue elsewhere that's causing the sounds...

I did notice that the duck calls are louder in cold weather! just a POS, really!

jcman

The crankcase vent valve controls positive crankcase pressures by intake vacuum, moisture laden oil vapors will ice-up and cause problems even on a good valve depending on the type of oil and short cold drives.

tester123

Ok, so let me see if I got it right. Blow-by gases build up in crank case and through crankcase breather tube, come up to this Crazy PUCK or CCB valve. Since there is vacuum under valve cover(s), these vapors are vented into VC(s). However, there is an inlet for outside air on this CCB valve. What's the purpose of that? In other words, if you know, would you provide a detail operation of this POS?

One thing I noticed is that opening oil filler cap on engine when running causes lot of air to be pulled in and some times this puck goes crazy / makes more noises etc. I'll post the exact nature of its operation tomorrow.

jcman

The outside air inlet question/answer, because the part is really considered to be a regulated valve with a diaphragm and equalization must be present for opposing forces to react effectively.

I believe I explained the operation of the Crankcase Vent Valve and this will too...

tester123

Resurrecting this thread as I have not been able to clear the issue. I ordered a new part but the issue seems to be something else. Further, to see exactly what I am talking about, plz see this video: A comment for the video mentions that even a new one didn't solve the problem... and another comment suggests replacing vacuum lines. When it had Secondary Air issues, I replaced ALL hoses good/bad ones with new tubing, checked recently again and they are in good condition.

This is driving me nuts and I can't understand what / how to solve this. I doubt the new part will do anything different. I welcome your input.

jcman

Is the valve still honking like a goose?

jcman

One thing to keep in mind is the SAI system has nothing to do with the crankcase ventilation system or the evaporative system, they all use engine intake manifold vacuum but are essentially isolated some with small check valves.

On the rear of the VC's there is are ports with plastic tubing that meet to a tee fitting to connect to the CCB valve, the other fitting off the valve is under direct engine vacuum to eliminate high positive crankcase pressures.

The 4.2 engine is not one I've worked on so I'm not sure what type of breather material it has, if it's the brittle plastic stuff I'd guarantee it has a crack and it's leaking which would emulate a loose oil fill cap.

tester123

Yes, it is still honking like damn goose ! To me, it is quite annoying (for others, very confusing as to why I'd imprison a goose under the hood). Anyway, I know what you mean by SAI and EVAP has not much to do with it. When doing the TB and VC gaskets, I cleaned out everything where the return hose from PCV to oil separator section in VC. No obvious blockages etc. except some light oil sludge. Still cleaned it all out and functionally, it looked pretty straight forward. Even then it quacked after that big job was done (didn't think it was going to go away anyway since I didn't find anything to indicate otherwise).

Here are my thoughts:

1) I've been seeing P0441 code and that N80 was replaced not too long ago. Last I checked, it was clicking and blowing air into it, seemed to work fine. Will check again but, I am wondering if these both are somewhat related.

2) The PCV was replaced (aftermarket); looks and inner workings are exactly like the original. The original failed as inner diaphragm crumpled. The honking was there ever since the new part was put in. I opened it couple times and cleaned/stretched spring/sprayed wd40 (yes, true mechanic) to quiet it but quacking comes right back if not a minute later. So, another new part might not solve it..

3) I am suspecting the vacuum check valves. They are OEM parts and not sure about their condition. They are one way valves right... I'll have to take a closer look.


I am resolved to fix it in its lifetime before this car goes to junkyard! I highly doubt that this is by design. Can you imagine a brand new car with random horn-like feature?

tester123

UPDATE: Finally, gave up and spent $120 to get the Original Audi part. Don't know because it is still new or whatever, the sound is GONE! I rev'd the engine few times and no duck quacks or Womp Womps! Also, when the oil cap or dipstick is open, (with aftermarket Valve the sound was very loud) there is a slight whistle like noise instead. Engine seems to run much better (perhaps, due to the oil change); anyway, will keep an eye and let you guys know if this is the fix after a few days. For now, it sounds like a mature Audi engine.

kelisko

I wonder why you did not opt for the original Audi part in the first place. Why buy aftermarket parts when original parts are available, even if they are more expensive? Isn't it worth it?