Hi all
i did some logging over the weekend and I seem to have an actual vs request boost delta or about 3psi.

my mind first goes to bypass valves but I do also worry about the intercooler hoses and connection to the intercoolers. I have a set of BPVs to throw in but wondering any experiences people can share of issues they have seen and resolved.

thanks in advance car is hitting 30k



Example of connection

BPV installed one outlet pipe. Part spins easily in pipe hmmm

 

Another note I went back and saw I had a good amount of play in my passenger side outlet hose connections.

 

I have a 996 Turbo and a 991 Turbo.

In the 996 Turbo world, it is pretty much standard procedure to do boost leak tests regularly to identify cumulative smaller and sometimes larger leaks. It's pretty easy to do on a 996, pull off the turbo-to-intercooler hoses at the turbo,, plug one side, pressurize the other side to ~1 bar, make sure it holds pressure relatively well (maybe 2 psi drop in 30 seconds), and listen for leaks and look for leaks with soapy spray. This testing is really super quick and easy once you have the right plugs... Other than getting the car up in the air, you can boost test a car in about 10 minutes. Now finding the leaks, if they exist, obviously can take longer.

I haven't done this on my 991, but the Turbo plumbing is remarkably similar, Rather than trying to guess where the leaks might be based on mechanical rotation and play, I'd see if you can just pressurize the system in a similar way with some test plugs and an air compressor and find out for sure where your leaks are coming from.

Here's a thread about doing the boost pressure testing on a 996 turbo, I think the primary difference will be how the intercooler hoses connect to the turbos on the 991 and if similar test plugs can be used...

https://rennlist.com/forums/996-turb...implified.html

 

Thank you. Yeah I am used to this in my Audi past world and having to disconnect the evap linesand going intake all the way through boost side to the TB and plugging there. Seemed way too hard on the 991 to do that full span so thank you for the link. The 991 also has “Wiggins style” hose ends vs hose clamps to plugging it will be tough. May need to make some custom hoses to do this....likely to replace the turbo outlet to IC side. Hmm

things to ponder

 

Is the inlet side of the turbo a normal hose clamp? If so, you could use some simple silicone couplers and pressurize through the turbo... Not my preferred method as sometimes you can get phantom leaks through the turbo oiling system, but if the turbo inlet is standard hose clamps, it would be simple to set up a test fixture.

 

Subscribed.
The timing of this thread is spot on - I ended up getting code P0299 (Boost pressure too low) and the car was definitely underpowered. I picked up the car tonight and drove off but POP, I lost all boost outright. Thinking it might be the charge pipes that may have burst.

 

Wjm3, I would do a pressure test to avoid the guessing part, every once in a while it doesn't hurt to check the whole system, especially if you have a tune or hardware changes.

I have had many instances even on very low miles Porsche turbocharged cars, where little boost leaks were there and you never know about them until you pressure test them. I don't know how much they charge in the US, but it is almost a routine for me every few months. My current 991 has boost problem with only 500 miles on it

 

Any other codes Kong?

 

Jean,

• · P2083 – EGT Sensor BANK 2
• · P0299 – Boost Pressure too low
• · P0138 – O2 Sensor downstream of cat, BANK 1
• · P0421 - O2 Sensor BANK 1 (due to high flow cats)
• · P0431 – O2 Sensor BANK 2 (due to high flow cats)

Here are the mods to the carMods on car –

• · Cobb Tune (TPC)
• · CSF Intercoolers
• · Kline Inconel Turbo Manifolds
• · HJS 200 Cell Cats
• · Kline Inconel Exhaust

Here's a synopsis of what happened -
A month ago, I was at Pitt Race and on day 2, the car ran with a little reduced power which I had attributed to higher temps and the car pulling boost (from our discussions on the track thread). I ended up running VIR and Summit Point before finally the codes appeared. I used the Cobb to clear the codes (Which didn't reappear again) and in retrospect, I should have left it in the memory banks to read with my PIWIS.

I dropped the car off at the dealer (where my friend is a P-tech) and it turns out, the diverter valve was not closing all the way due to a bad check valve. Unfortunately, I picked up the car last night and when I opened up the throttle, I heard a "pop" sound and lost all boost. I tried to actually get a DME fault to appear to help diagnose by giving it slightly higher throttle angles. I ended up turning around and bringing the car back to the dealer to look at hopefully today (I'm back at Summit Point this weekend for 2 days). t was interesting driving the car in "NA mode".

 

If you hadn't mentioned the pop sound I would have thought it is not a boost leak, but been there before, and this sound is so typical of a TB to pressure hose popping off.. Hope you get it sorted soon!

 

Thanks Jean. I would have never thought a check valve would lead to the boost leak. I knew something was wrong when 2nd gear corner exits lacked a little bit of haste.

t's always good to have experienced folks that know the platform chime in.

 

It’s just a possibility but I think the black hose is where the boost leak might be coming from, especially if you have an IPD fitted, the clamp from one of the sides might have come lose.