Getting some ticking noise from the engine (4.0 01 308). Usual clicking and tapping at startup, from VVT; this new noise sounds more rod knock. new secondary tensioners, so I was concerned it might be primaries or loose secondary chain.

Using a stethoscope, there is normal reciprocating whines from intake manifold, exhaust manifold, VVTs, water pumps, alternator, AC, PS. loudest on cross over pipe behind thermostat tower. Pulled the plastic shrouds and noise emanating along injector rails; most from injectors on port side -- loudest is # 8 (B4, left bank, furthest aft), with # 7 second loudest. Comes and goes, gone above 1500 RPM.

No codes, trims are normal. Added some fuel system cleaner: hopeful..

Any thoughts/guidance?

 

Check for loose spark plugs

 

Thanks, but no. Not this time. Torqued on the money. I put the stethoscope on the injectors, the noise is there, no where else!