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-   -   PCV bits under the Intake Manifold (https://www.audiworld.com/forums/audi-original-s-cars-25/pcv-bits-under-intake-manifold-2842808/)

GoHeels 02-18-2013 02:10 PM

PCV bits under the Intake Manifold
 
1 Attachment(s)
I noticed the PCV stuff under my IM is oily compared to pictures on Dave's great PCV write-up, and is likely original since they have factory clamps. So today I got under there with a camera to see what's going on, and what might be the causing the oiliness.

Looking at this picture, I think I see a blown "T" hose, which is likely causing my oily mess, and who knows what other issues. Unless there's a 1-way valve at the IM connection (top arrow), which I doubt, I would guess this is likely a boost leak of sorts, and could be costing me power.

So today I ordered both small hoses in silicone from 034, as well as their billet PCV check/bleeder valve. I imagine its going to be a challenge to get those upper factory clamps off to remove this stuff, and to get the new T-hose attached to the IM. Hopefully I can get some small clamps tightened in there.

Also put an arrow on the turbo coolant return line a shop installed, which I hope is silicone. The inside half is red, the outside half is green.

scarman 02-18-2013 03:07 PM

I think you can see why changing that little coolant hose has resulted in breaking so many of these emission parts.

A twist with a 1/4" or 3/16" screwdriver will usually loosen the crimp of the oetiker clamp. It may be loose and oily enough to just pull it off.

This is a good place to use new oetiker clamps. Here is a good, inexpensive source:

http://www.kegkits.com/Merchant2/merchant.mvc?

I'm going back over to the other forum. Hit me over there if you need more info.

UrS4boy 02-18-2013 03:17 PM

The good news is you have found the source of boost leak. That "T" is the junction of the connection to the N80 Evaporative Emissions control valve and the PCV system's one-way bleeder valve. Since it is up stream of the bleeder valve, the "T" is under pressure during boost. The fact that your "T" has split = boost leak. Item 14 in the second diagram and Item 1 in the second diagram = 034133367E. I am stealing your photo for the PCV system and/or boost testing posts. (I'll give you credit).

http://12v.org/urs/UnderTheIntakeManifold_2A.jpg

http://12v.org/urs/CrankCaseVentilationSystem_3A.jpg

http://12v.org/urs/EvaporativeEmissi...lenoidPN2A.jpg

GoHeels 02-18-2013 05:14 PM

So it is a boost leak, not just a leaky PCV/N80 system... Well that's a scary thought considering the S6 has been driving like a 4-door Carrera since the work I did last month. I only noticed by reading your write-ups and seeing the oil. Now my right foot is twitching at the thought of it actually boosting better when I fix it. 8)

And a clamp set is tempting Tom, how cool are those things. I could grab the small size kit for $55 and be set for life. I could have used some of them already.

I've got a new fan switch (22mm?) to install while I'm in there, to hopefully get the fan and after-run pump working again. Not sure if I can access the thermostat or not, but I'd like to get 1 and change it with the housing. I have the short hose that goes behind it too. Guess I'm gathering parts to do this next week.

lliejk 02-18-2013 07:09 PM

Those are all good PM (or in your case, maintenance) things to handle. Great eye. Your car is lucky to have such an observant owner.

Ed

GoHeels 02-21-2013 01:30 PM

2 Attachment(s)
Picture 1 - top of the "Tee" hose, which was ripped twice as bad as the bottom
Picture 2 - lightly pressing down the spring loaded plunger, it stays centered and goes down ~1/2 inch

I ended up only changing the "Tee" hose for now, because the new valve and bottom hose combo are 50% longer, and I didn't want to force the breather tube down that far to connect it. I'll try again later, perhaps it has more play when the engine is warm, but I wasn't about to break it to accommodate the longer lower setup.

My original breather valve was nearly air tight blowing through it, and after cleaning the grit out of the valve opening with a paper-towel I couldn't blow through it at all. In my hand it seemed to work quite well, and the bottom hose it sits in was okay, since it isn't under boost and is rather thick. My "Tee" hose was destroyed, and I imagine I'll notice an improvement when I go drive it. I'd be willing to guess anyone with an original has nearly the same issue, especially if the car is chipped.

UrS4boy 02-21-2013 03:51 PM

Thanks for posting. So the one-way/bleeder valve is NOT a ball valve like I had previously thought but a spring-loaded diaphragm. Opens against the spring with vacuum in the intake manifold, closes with the spring and boost pressure, under boost. Failure must be related to a rip in the diaphragm.

GoHeels 02-21-2013 04:40 PM

Yeah, and that's a hard piece of plastic the screwdriver is pushing, thin like a small dime. Perhaps
it's sorta thimble shaped with the spring behind it.


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