Overboost

[audijay73]

Can a intercooler leak cause overboost and make it sound like it has an atmospheric dump valve ?
Because whatever it is its doing my head in
Things checked
All vac hoses
Cooler hoses
Turbo
Actuator movement
Fault codes just saying overboost and number 4 glow plug kaput
Any Ideas welcome
Cheers jay

[sy.]

A leak would not cause overboost the sound my be compessor surge caused by overboost, a8 tech will know for sure but may be n95 valve is your vag code something like Charge Pressure: Maximum Limit Exceeded

[drpellypo]

How have you checked the turbo? E.g - was it totally disassembled?

[audijay73]

Sorry guys turbo vanes checked and cleaned all ok it just sounds like it's decompressing air in the intercooler if you imagine what that sounds like. Could the vac box have anything to do with it ? But when I unclip the part with lots of pipes on air escapes so to me it's holding air.
Is the thing I am calling a vac box the n?? Valve

[sy.]

yes vac box = n95 there was a fault with some causing overboost im sure is been covered on this forum too

[audijay73]

Ok cheers mate will get one
I'm feeling more money leaking out of my pocket again

[audijay73]

Unplugged n95(vac box thingy) only one of the pipes is sucking air all others not doing any thing .
Gave it a rev to about 4000 rpm let off the gas and no strange noise as before , took it for a blast slight turbo lag but pulled ok tried to get it into limp mode as it would before I disconnected n95 and fault didn't come up so to me it's the vac box (n95)
How much are these I take it it's a dealer part
55 plate 2.0 tdi 140

[audijay73]

Anyone ???

[phil76]

What car and engine would help people a lot mate,as petrols suffered with the old style DV's blowing themselfs apart causing boost issues

[audijay73]

A3 2.0 Tdi 8p engine bkd sorry mate I thought i included it
It's not n95 valve as have tried two new ones ordered a recon turbo so hopefully will keep you posted on developments also replaced map sensor