Generac Power Systems MAC 950F Owner's Manual page 24

Troubleshooting
Problem
Abnormal Engine Noise
Turbocharger "Screams"
Turbocharger Noise or Vibra-
tion
20
Cause
Worn main or connecting rod bearings
Excessive crankshaft end play
Loose main bearing caps
Worn connecting rod bushings and piston
pins
Scored pistons
Worn timing gears or excess backlash
Excessive valve clearance
Worn camshaft lobes
Worn rocker arm shaft(s)
Worn valve guides
Damaged valve retainers
Loose or worn rocker arms
Bent pushrods
Broken valve springs
Bent connecting rods
Worn flywheel
Loose flywheel
Excessive piston to liner clearance
Excessive thrust bearing clearance
High oil viscosity
Leak in intake air system
Bearings not lubricated (insufficient oil
pressure)
Air leak in engine intake or exhaust mani-
fold
Improper clearance between turbine wheel
and turbine housing
Broken blades (or other wheel failures)
Solution
Contact an IASD
Determine cause of lack of lubrica-
tion; repair as required or contact
Contact an IASD
Check intake and exhaust manifold
gaskets and manifolds; repair as
required or contact an IASD
Inspect turbocharger; repair/
replace as required or contact an
IASD
Inspect turbocharger; repair/
replace as required or contact an
IASD
Owner's Manual for Flameless Air Heater