2012 Verano 2.4 ecotec no heat

[pmartinez06]

Need some serious help. Tried all the normal things.
Symptoms: slight overheating (190-210F), cracking/popping expansion tank, overpressure leaking, fan turns ON, lower radiator hose cool to touch, upper hose hot, both hoses pressurized engine running, no heat from vents.
Attempts: replaced thermostat and water pump, numerous Hot/Cold cycles, burp funnel, Coolant Vac Bleeder/fill kit, tested new thermostat and tank cap.
Afraid to drive, don’t want to pop hose and overheat. Plz, anyone with experience, what am I missing?

[aleekat]

If you know someone with a thermo gun, shoot your radiator. Sounds clogged.

[maxwedge]

If the hoses get pressurized very quickly from a cold start, could be a bad head gasket.

[pmartinez06]

Update: Repaired. Balance shaft (secondary) timing chain broke.
Taken to repair shop. While waiting, I found a post on a Malibu owners website describing exact same issues. That owner found the same problem. I didn’t mention it to shop but, they found it a day later. Add another to 2.4 ecotec timing chain issues.