Turbo Pressure Sensor Leaking Purple Potting Compound - Replacement

Turbobeginner✓ OP Confirmed

Problem

The turbo pressure sensor (Toyota part #39420-14020, ND #100798-0890) develops a sticky purple/tar-like goo that oozes from the sensor body over time, dripping onto the fender. The internal potting compound degrades due to years of heat exposure, losing its solid form and becoming viscous.

Sticky purple/tar-like goo oozing from turbo pressure sensorGoo dripping onto fenderVisible stretch marks on sensor potting compoundFoil sticker on sensor beginning to sink inwardSensor body looks puffy when hot

Root Cause

The urethane potting compound inside the turbo pressure sensor degrades over decades of heat cycling in the engine bay, losing its solid state and becoming a viscous, sticky goo that seeps out of the sensor housing. This is a material degradation issue common with old rubber and urethane compounds, possibly exacerbated by an improperly cured batch or extreme climates (e.g., Florida heat).

Confidence

Moderate confidence — Original poster confirmed this resolved the issue

View Original Thread →Posted July 2023 on SupraForums.com