blitz

99.5 1.8tqms/garrett 1.05bar chip custom remus with newly installed boost guage. The problem is that at WOT in fifth, from about 3,000 rpm, boost guage flops between 10-12 psi. On good days, I can get a steady 16psi reading. I know my bypass valve is starting to go, due to the groan coming from engine bay. Reading the archives, this should only hold a lower boost, possibly 10 or lower psi due to leaky valve. Now the quesiton is why is my boost guage flip flopping between 10-12 psi? It's very apparent is exhaust note aswell. The variance in boost follows a variance in exhaust note. Almost like I have a itchy right foot and cant keep it down. Please help or advise. Thanks in advance.

DocWyte

I've had this problem too, but only at lower rpm, like under 3000 rpm. It's the ECU pulling out timing and boost down low in the rpm range. Basically in a high gear at low rpm you can really load up the turbo and create lots of boost. This is great, but then the ECU starts to pull back timing to keep things from pinging and that reduces the boost. IT senses everything is ok and lets go, then the cycle repeats...

dingster

What version chip do you have? Garrett has no-surge chips for cars with such problems. My 99 Passat did the same thing and I got a no surge chip and the problem went away.