Injected with a
Join Date: Sep 2008
serious boost pressure problems 156 2.4 20V M-jet
Guys, a whole bunch of people now are trying to sort out my problem....any ideas are very welcome
The problem is the following:
The car overboosts for some reason and then offloads the pressure or whatever the correct word for that is...you can hear it as you go. For example going on 3rd gear with 1800rpm and then you suddenly floor it....it starts to build up pressure then at 2100rpm it goes psssst (bit like a blow-off valve)....and then builds up pressure again until lets say 2400rpm, and loses pressure again...it only makes it (well noticeable) between 1900 and 3000rpm...when you're driving it it feels like multiple surges...
I must have a log somewhere but it generally loses around 300mbar....
No error codes
things done so far:
tried new MAp
tried new n75 valve
tried new vnt actuator (The thing that looks like a wastegate)
cleaned variable geometry vanes
re-mapped the car incl. almost completely eliminating the n75 valve's sensitivity...
checked vacuum lines and pump
all gave little or no improvement....
Any ideas are welcome....
2004 156SW 2.4JTD M-Jet 20V
Currently: 189Whp@3850rpm / 410Nm@2400rpm
EX 1999 146 1.6TS 16V