Q: I have a 1992 Freightliner FLD 112 with a Cummins engine model L10/310/E. There’s a compression leak around the head gasket. My mechanic recently changed the manifold gaskets, one of which looked slightly damaged. Unfortunately this did not solve the leak. The truck has 500,000 city km. Would it be reasonable to change the head gasket, and possibly replace the head? Or will I likely run into more problems after opening up the engine considering the age of the truck?
Thanks in advance.
A: The L10 engine repair action depends on which joint is leaking and what the joint is leaking, i.e. air, coolant, oil, or combustion gas. If the head gasket is leaking oil or coolant, then the correct repair would be to replace the head gasket. If there is an air leak (turbocharged air) between the rocker box and the top of the cylinder head, then replacing the rocker housing gasket would be the best repair.
In either case, the technician will need to inspect the sealing surfaces for flatness and cracks of the head and cylinder block. After cleaning the head deck and combustion face of the cylinder head, an inspection should be performed with good lighting. Use dye penetrant (typical crack detection spray-on fluid) and white developer to help. If both surfaces are free of damage and cracks, then a standard head gasket replacement will fix your problem. I would not be concerned with the engine mileage (500,000 km). With continued good maintenance, the engine should be very capable of running an additional couple hundred thousand kilometers.