Engine Won't Stay Running After Head Gasket Job - Failed Aftermarket Intake Gaskets

Engineintermediate✓ OP Confirmed

Problem

After a head gasket replacement on an 89 Supra (7MGE NA), the engine would start but immediately die unless given throttle. Occasionally it would briefly idle at ~450 RPM, surge up 200 RPM twice, then stall. Spark plugs smelled strongly of fuel and were fouled. A high-pitched whine was audible from the plenum area, and hissing could be heard from the intake side after the engine died.

Engine starts but immediately dies unless given throttleBrief idle at ~450 RPM with surging before stallingHigh-pitched whine from plenum areaHissing from intake manifold area after engine diesSpark plugs fouled and smelling of fuelStrong fuel smell during start attempts

Root Cause

The aftermarket gasket kit (Evergreen/Mizumo Auto) used during reassembly had paper/felt-type gaskets that blew out under pressure. The plenum gasket was found completely destroyed with multiple rips. The intake manifold gasket had the same failure. Additionally, the mechanic did not properly clean the mating surfaces of old gasket material before installing the new gaskets, and improperly applied RTV to the EGR inlet gasket on the plenum side (which gets too hot for RTV). These combined failures caused massive vacuum leaks preventing the engine from idling.

Confidence

High confidence — Original poster confirmed this resolved the issue

View Original Thread →Posted December 2025 on SupraForums.com