Have bought an immaculate 2005 996 TS with only 20.000 miles. Car looks smells and feels new. Problem is taht it doesnt pass 0,7 bar of boost. Car is 100% stock apart from a Ruf exhaust. Nothing else
Any ideas as to what could be causing the low boost issue ?

 

take it to the dealer.
Same problem my buddy had after he bought his 05 TTS Cab with Tippy.
I told him it was slow after driving it. I do not recall what they did.
good luck

 

boost leak?

 

Pull codes.
Boost leak test.

I would image any 10 year old car will have boost leaks if the previous owner was not diligent in proactively replacing hoses/clamps during other maintenace.

I would suggest - if your shop goes in, you have them do as much replacement of questionable hoses and clamps as practical.

<ask me how I know....>

 

Done boost leak test. No issues there. Could it be the wastegates ? Should i get modded ones with stiffer springs on a stock X50 car ?
I know protomotive sells them with 1.2 bar spring

 

No CEL? No other symptoms?

You may not be driving the car in the manner in which it needs to be driven in order to see full boost.

Even with my 996 Turbo sometimes it is hard to see the 0.7 bar boost. Often all I see if 0.6 bar. This appears to be the case when the weather is cooler. The DME is able to satisfy the torque demand of the driver with just 0.6 bar of boost. At other times, in warmer temperatures under otherwise the same conditions, on the same road I see 0.7 bar. And on other roads, at high elevations, I have seen 0.8 bar, even 0.9 bar boost.

Anyhow, be sure the gasoline is top tier, fresh, and the right octane grade.

Be sure the engine is fully up to temperature. Then drive it 10 more minutes just to be sure.

Find a deserted road with lots of room and in 4th or 5th gear at around 2.5K RPMs mash the gas pedal to the floor. I mean mash it. And hold it down against the carpet.

Watch the road and the boost gage. As the RPMs rise the boost should peak and remain at its peak a moment or so, long enough to not to be a "glitch". As RPMs continue to rise though the boost should drop off. Normal.

Or if you want take the car in and have it checked out. There may be a boost leak. My experience is with my 03 Turbo (now with 113K miles) the stock hoses -- now over 10 years old and with 113K miles on them -- hold up real well.

In talking with the techs about boost leaks what I've told is what happens is someone who is not familiar with these cars works on them and in putting the boost hoses back on in sliding it on pulls back a piece of rubber at the edge of the hose. This makes for a boost leak.

The techs tell me they are particularly careful when reinstalling the boost hoses to ensure this doesn't happen. The boost hoses have been off my car several times now and still no boost leaks.

 

Will check the N75 valve tomorrow. I read that if it goes wrong the car overboosts. I have the opposite issue. Lower than stock boost (0,7 to 0,8 max and very occassionally). Does the N75 cause low boost issues or only overboosts which triggers the safe mode ?

 

disconnected n75 and you have low boost...a def n75 and you will see a code with durametric...why change it without any failure code?

 

On a stock S, same as X-50, you should see .8 and when cool out occasional .9 ...