I had a 1.8T Audi A4 and 1.8T Audi TT several years ago. It was common knowledge(esp on the TT) that the diverter valve would need to be replaced if you chipped or upgraded the car, and even on a stock car if it started "honking" you knew a replacement was needed.

Well, when I lift after boosting in my Cayenne Turbo, I hear a honk noise. Granted it sounds different, but an Audi/VW 1.8T with a single diverter valve(dv) is going to sound very different than a Porsche 4.5L twin turbo V8 with dual dvs.

Sooooo...anyone replaced theirs yet with aftermarket? Anyone selling a set for the CT?

I had a Bailey and a Forge and TurboXS value in the past. I felt the Forge and TurboXS were the best.

Anyone know if I can even reach the valves to replace them? Can't see much in the engine bay...

 

I am working on a solution to this....stay tuned.

I found where the stock DVs are located. Underneath the airbox which means removal of the wheel well is required.

Not sure if this is also an issue, but there is a SERIOUS kink(more than 90*) in the vacuum hose going to the DVs.

 

I think I may have a faulty DV's...

I've been tracking down the source of a honking sound Ive been experiencing for a month now.

Its loudest when accelerating from a stop up a hill (high engine loads) but the honking only occurs for a second or two.

Once moving, if I WOT it is difficult to duplicate the honk - or perhaps I simply dont hear it anymore due to all the other noises ie: exhaust

Also, during the honking, I can feel it through the accel pedal and steering.

Does this sound familiar to all the people who have experience DV failures in their Cayenne's?

I'm hesitant to replace the DV's as I have found other threads where people with similar noises have replaced the DV's and the noise is still there....

ANy feedback would be appreciated!

Mike

 

New diverter valves make an amazing difference. Changed mine and they seriously improved the performance about the same as putting the cat bypass on.
Much quicker boost spool up between gears which if you think about it gets you to peak hp faster. I was skeptical.

Had plans for adding a chip as well, but after DV's, k&n drop in filters and diverter valves the performance is surprising.

And as far as the kink, it is on the vacuum side and non-consequential. But when you change out the valves, you can fix it if you want with either a elbow or by re-arranging it.

 

We actually have the valves in stock for the Cayenne. Especially if you plan to or have already chipped the car, they're definitely a worthwhile investment.

The part listed says 911 Turbo, but the same valves are used in the CTT. Keep in mind...you need two.

http://www.championmotorsport.com/pr...p/cmsdv02b.htm

 

I will be vacuum testing my stock DV's this weekend and go from there... I'm still not 100% sure my noise is from the DV's

I also talked to a friend who works at the local porsche dealer (3 years) and he says he has NEVER replaced DV's on a Cayenne.... which makes me wonder if the noise I am experiencing is truly from the DV's...

 

I've replaced them before... They do fail. Make sure you buy a pair that includes the little plastic 90 degree elbow or your vacuum line will kink. It's as straight forward on the install as it would have been on your 1.8t's.

 

Ours are 90 degree already

 

can anyone confirm though that when DV's do go bad, do they make a honking type sound?

Also, at what rpm do they make this sound? I only get it at lower rpms ie: btwn 1500-2200rpm but no noise at higher RPMs under load - I also get about 0.75bar so if my DV's are bad, they can't be *that* bad (yet)

 

Tom, thats perfect.

And there's no exact science to it, just depends how bad the fault in the diaphram is. It may make the 'honk' noise you're referring to, it make hiss, flub, fart, or make absolutely no noise at all. Best to get it diagnosed asap.

 

Mine were not holding boost, occasional honking noise but more heavy surging under hard acceleration. Once I replaced them they made a big difference, running fabspeed tune, cold air, plenum, bypass pipes with 90k miles and running strong. Now I always smell my intercoolers when heavy on the gas for a long stretch (0-70,80ish), smells like well water (sulfur smell) looking for a set of 09 CTTS if anybody knows of a set? Champion do you guys sell any aftermarket or CTTS intercoolers???

 

Just curious why you would smell anything from the intercoolers (they are just air to air units) I could see smell from the exhaust (cats) or people complaining of the sulfur smell when the coil packs let go (burning smell). When your diverter valves fail will you get the hesitation at wot (jerking) without any noise or honking?

 

I thought the same thing, replaced plugs & coil packs thinking it was the smell, wasn't really a burn smell. I still had smell only after repeated highway driving with long pulls or hot engine with quick take off's up to 70 - 80mph?? My local guy said air flow through heatsoaked IC's??? Yes hesitation @ wot and big air release sounds wouldn't really call it honking sound? Once I installed new DV it ran great and it's been 6k since.

 

shop was to busy today so I had no chance to work on my own car

will have to wait until next weekend to check the DV's