🌀 Quick Boost Spike Fix on My 930 — Simple Solution

[audiblypry]

Was getting random boost spikes on my ‘86 930 — thought it was the WG spring or overboost switch.
Turned out to be a cracked vacuum line to the wastegate! Replaced it with high-temp silicone hose, and now boost holds steady at 0.8 bar.

Old school fix, but worth checking if you’re chasing boost weirdness.
Anyone else dealt with this?

[908/930]

Just checking that the silicone hose you used is a reinforced type? That hose also required to hold pressure.

[mark houghton]

Good deal! But to be clear, the hose to the WG is not under vacuum...it's pressure. And the over-boost switch/sensor will not cause an over-boost scenario should if fail. Designed to cut off your fuel pumps in the event of over boosting due to a faulty wastegate (or plumbing to it as you have found).