Spyerx

How does one diagnose this?

I've heard this whistle (well come sort of slight whistle) on mine on very rare occasion. I just had my front and rear seals replaced (they never leaked) when I had my engine drop to weld coolant lines. I heard this same whistle a few weeks back when just cruising on highway. It sounded exactly the same as before I had seals replaced. Of course there are no codes and car runs very strong.

audipwr1

Rms has 2k miles on it

Fisher

Possible related article in the October 2014 issue of Der Auspuff, PCA Santa Barbara Region.
Pages 21-22

http://pcasb.org/DerAuspuff/2014/2014-10.pdf

PORSCHE BREATHER SYSTEMS

BY CHRIS ANDROPOULOS
the teCh RePoRt
Santa Barbara Region Tech Editor

“The first symptom of this failure in 996/997s may be a “check engine” light and lean running fault codes, which is sometimes accompanied by smoking from the tailpipes immediately following engine startup. This typically occurs around the 60,000-70,000 mile mark. A less common symptom of failure is a loud squealing or squeaking noise while the engine is running; this is the sound made by oscillations of the torn crankcase vent diaphragm!”

Spyerx

Wrong engine. That's a 996/997 flat 6 pre dfi and not mezger.

Fisher

If the article isn't applicable, then where can I find info about the Mezger crankcase vent?

audipwr1

Not the right noise either

Fisher

Found a discussion on the 996 GT2/GT3 forum where they were changing the OEM breather for a RSR crankcase breather to gain 5 HP. No information about pressure or vacuum changes or what affect on the engine main seals. Just that it’s difficult to access the breather without pulling transmission. See post #68 and 69.

https://rennlist.com/forums/996-gt2-...reather-5.html


Also this TSB:

http://members.rennlist.org/jandreas...ing%20Ring.pdf

“We have since discovered that a leaking crankshaft sealing ring on the flywheel side can also be caused by a leaking or manipulated1 engine vacuum system. If an oil leak is found in the area between the engine and transmission, the vacuum system must be checked for leaks before starting repair work; see �� Workshop Manual ’135919 Leak-testing the vacuum system - GT3’.”

So, it seems that engine breather valves can make noises when they are starting to fail and also have an impact on engine main seals leaking.

Spyerx

Best pic I could find from Google and I think this might be RS Rangers engine before the build... :-)

See circled, this is the crankcase vent system. This engine runs under vacuum in the crankcase (windage). You can see the pipe runs from crankcase to oil tank to intake near throttle body.

Anyway, I'm not super technical on these engines but if I read correctly this is how this engine vents.

if incorrect ... please let me know I'm curious too.

Griz: I'm aware of that breather the design supposedly changed on 997, that was a 996 trick and the way it increased HP was by increasing vacuum and reducing windage losses on the internals. If you look at PET you will see 997 has a check valve right near the oil tank on the L shaped pipe. The 996 doesn't have this. The breather is installed right near that lower arrow.

Keep in mind I literally just had my seals replaced front/rear and they were not leaking, the rear seal had a very minor amount of seepage (totally normal). They are not leaking now.

I've also only heard this slight whistle 3 or 4 times in 18mo I've owned the car.