What's Up With My 996TT?
 

Hi guys I'm new here and am in need of some help

Whenever I start-up my 996TT it makes a strange noise from the engine compartment for 3-4 seconds "BRRRRRRRRRRRRR"

Imagine blowing down a length of plastic piping - that's the sound

It seems to stop when I pull away

Someone told me it could be a leak somewhere, and suggested I check the boost pressure

I'm not too sure what's the best way to do this
But - if i drive slowly in 2nd gear then "floor it" until the redline I get 0.4Bar
I get the same reading if i do this in 3rd and 4th gear too

Is the boost pressure meant to be higher than that?
Does this sound like a leak from somewhere?

BTW - car is completely stock to my knowledge (only owned it 5 months)

Thanks in advance
Ant

I you have a blown hose.... one that came off maybe...
just take it to a shop have someone that knows take a look at it... chances are they will find something else as well.
You need to pressure test the car... fix the leaks... ALL the leaks...

stock 996 TT should see higher boost, 0.6-0.7bar if I'm not totally wrong

Thanks

I also thought boost should be around 0.6-0.7
Can anyone confirm this?

Do you think a loose pipe is the cause of both the Low pressure and the noise?

I've heard the DV's are prone to failing - could this also be one of the causes here too?

.7 bar for standard
.8 bar for X50, GT2, Turbo S

Do not drive your car hard until you get it checked out. If you have a leak, your turbos could very well be spinning beyond the design limits trying to reach .7 bar.

Probably... imagine a split rubber hose- air leaking out, causing the rubber to vibrate. BBBRBRRRRRRR... Or the DVs are leaking and you are hearing that?

Once you know what to look for it would be pretty easy to inspect...

A

Does your car throw any dashlights? I had a similar issue when one of my boost hoses had a tiny hole in it because it was cracked (threw a CEL light for me). Hopefully the leak test will take care of things for you.

Good advice - thanks

There are no dash lights showing up
Just a strange sound and a loss of boost pressure

Where abouts are the DV's? - are they part of the turbo unit itself or are they connected to them? (i'm still learning - turbos are new to me)

I ask because - If the DV's need replacing and I decided to upgrade to k16/16Gs would that take care of the DV's? or would they need sorting separately?

Separate. Look at this if you want to locate the DVs
http://www.turbo911.com/showthread.php?t=287

thanks ard - very interesting read

i have been looking at the turbo upgrade kits and have seen the external wategate and pipe coming off of the header pipes

what's the reasoning behind this?
is it just for the k24s - or could i put these headers and wastegates on the k16Gs?

I promise after this I will learn more about turbochargers and their workings before asking any further questions I could easily find had i done a bit of research first

Thanks

I've just ordered some new Forge DV's - the adjustable ones

How long would you say it takes to replace them?
And whilst I'm at it is it worth changing/upgrading the F pipe - or is it fine as it is?

People will say to replace it. I'd say replace it if it needs it.... what year? after 4-5 years stuff can start getting brittle, so perhaps new will be called for. Indeed, you may already have a split hose somewhere.

In the external wastegate stuff- plenty of other simpler options for you- read up.

I'd say you want to take a 'personal inventory' as to what YOU want....what are you going to do with the car (track, just street/drives, etc) and what level of performance you are seeking. Do you want to just optimize the basic platform, do you want modest upgrades- or anything goes but WITH CURRENT INTERNALS, or do you want a monster. What is your budget.

Took me about an hour to replace the DVs...

A