I'm fighting a P0016 error code in a 2007 4Runner I grabbed as a project, and finding similar sludge accumulation. Did you get any pictures or measurements of your #1 timing chain tensioner piston?
Mine is extended nearly 3/4", whereas pictures elsewhere (and the sludge/varnish marks on mine) have the piston around 1/3" extended. Seems to indicate stretched chain or failed guide. No noise at startup, idle, or cruise...just a short transient rattle when accelerating from idle to around 1200RPM which may be the chain or a heat shield under the vehicle.
My balancer timing mark is only ~2mm past the 0 indicator on the timing tab, didn't seem like enought to try walking the chain back 1 tooth. I cleaned solid sludge blockages out of the intake camshaft VVT oil passages, and replaced the VVT actuator/sprocket assembly. P0016 is now intermittent...only happens when the engine is cold and I'm running in low-RPM low-load traffic conditions.
Mine is extended nearly 3/4", whereas pictures elsewhere (and the sludge/varnish marks on mine) have the piston around 1/3" extended. Seems to indicate stretched chain or failed guide. No noise at startup, idle, or cruise...just a short transient rattle when accelerating from idle to around 1200RPM which may be the chain or a heat shield under the vehicle.
My balancer timing mark is only ~2mm past the 0 indicator on the timing tab, didn't seem like enought to try walking the chain back 1 tooth. I cleaned solid sludge blockages out of the intake camshaft VVT oil passages, and replaced the VVT actuator/sprocket assembly. P0016 is now intermittent...only happens when the engine is cold and I'm running in low-RPM low-load traffic conditions.