Updated: Apr 12
CARBYNE AUTOMOTIVE MECHANICAL WORKSHOP CASE STUDY
2016 Toyota Prado with 142458km on the odometer
Task – Customer initial request was to inspect the engine for an oil pressure light on and loss of power.
Customer advised that the engine oil light had come on and the vehicle was running rough and had no power.
We completed the following checks:
· Inspected Oil system.
· Conducted blowby test- Failed.
· Conducted compression test- Failed, out of OEM specification.
· Inspected pistons found Piston failure.
· Tested injectors – Pass- within OEM specification.
· Visually inspected oil pump- Pass.
Carried out the following diagnostic procedure:
Prestart check and visual inspection found no oil measured on dipstick.
Carried out visual inspection for possible oil leak, found no external oil leak.
Drain oil and measured engine oil quantity, only 5 litres present.
Engine capacity for this model should be 7.5 litres.
Found oil to be clean with no contaminants .
Refill engine to correct level for further testing.
Removed intake hoses and found oil residue in hoses, checked oil filter is clean.
Removed Positive Crankcase Ventilation (PCV) hose and run engine, found excessive smoke and pressure coming through hose, this is an indication of engine blow by.
Carry out compression check found the below results:
Cylinder #1 - 285psi
Cylinder #2 - 360psi
Cylinder #3 - 340psi
Cylinder #4 - 200psi
Injectors removed and tested for leakage and spray pattern; report returned within OEM specification.
We suspect engine blowby due to piston ring failure has subsequently caused engine oil loss.
This lack of lubrication to the piston cooling jets is the source of the failure to the piston fracture and forming a cavity in the piston crown which in turn has resulted in the loss of power.
Carbyne Automotive Pty Ltd
4 Ginger Street
Paget QLD 4740
07 4952 1195