fluttering noise from rear left

[Ron997TT]

Hi Guys,

A big hello to you guys! im driving a 997 turbo tip and i would like to share a problem im facing right now;

This happened 2 weeks ago. I noticed a fluttering sound from the rear left whenever i throttle. I have listed down the exact details;

1. light throttle on even road is fine, sound appears after half throttle or going up slope. On WOT, fluttering is very noticeable.

2. initially, the mechanic and i were bewildered by the sound. At first we thought it could be a boost leakeage, however subsequent checks on all hoses proved otherwise. And also, im able to maintain my boost level (odometer shows 1.2 bar, but i am running 1.5, 1.6bar on external boost gauge during tuning). For eg, in gear 1, 2, 3, im able to hit 1.2bar..

3. Things took a turn for the worse today. 1st gear, im only able to hit 0.7 then 0.6, 2nd gear 0.9 to 0.7, third gear 1.0 to 0.8bar. Something is very wrong now. This was done on highways in the early morning.

After sharing my problems with my Pfriends, i was told that the wastegate or the diverter valve could be the culprit, due to wear and tear or some other reasons.

Anyone here encountered this issue before? I cant send the car back to agent as its modded (exhaust, headers, ecu, brv, ipd plenum) and they will not entertain me unless i change them back to stock parts.

Anyone?

[David G]

The really sounds like the diverter valve. They are prone to failure. I had one go on an Audi TT and it was like you described. On a 930 I used to own I had a billet version. There are several different places that make these.

[Ron997TT]

Thanks David for your inputs..

Another point to note is that im able to hit 300kmh and still going.. with no air gushing sound.. i could hear the fluttering during initial pick up but when it reaches 100kmh on light throttle the fluttering goes away, till you apply more gas.

Anyone has similar encounters?