My buddies 2001.5 S4 is having a weird problem, sometimes he has boost under WOT, sometimes he doesnt, he'll drive for like a half hour without boost then all of a sudden he'll get it again. Is there a lose pipe somehwere? Boost leak? just looking for any advice you guys can give, its appreciated!! BTW he didnt use the HKS BOV, he is sticking with stock thanks to your feedback

 

Is it just random or does it happen only under certain circumstances, i.e. start up the car and no boost for a half hour?

Sounds like something might be loose, open the hood and have one of you rev the engine lightly and pin point any leaks on the hoses.

 

Happens random for him, he can start it up, have boost, then later on nothing, start up no boost, drive for a while and get boost...its really weird, I was just wondering if this was at all common, or someone else had a similar problem. Will try the rev with hood up though...thx

 

Sounds like it's going into LIMP mode.

Is the CEL on? Have you had the codes read?

It might be something like a going N75, DV's going, maybe even a TBB tear that
only shows up under boost.

 

YEah limp mode.. if it was a loose hose / pipe etc. youd hear it ...
plus the randomness -

any codes??