You love your GMC diesel and we here at Moose Jaw Truck Shop don’t blame you one bit. Nobody is perfect, however, and GMC hit a few snags with the Duramax LB7 engine. This 6.6-litre, V8 engine can be found in the Chevy Silverado HD, GMC Sierra HD, Chevy Kodiak, and GMC TopKick models manufactured from 2001 to 2004. There are five common problems that owners of these specific vehicles have had to deal with. Here is what they are.
Fuel Injectors
LB7 engines have direct-injection fuel injection. This means the fuel is sprayed into the cylinders rather than an intake manifold. The fuel injectors in the LB7 engine have a design flaw that causes them to fail. Signs you’re truck is suffering from this flaw include a misfiring engine, rough idling, acceleration and performance issues, and error codes that indicate the fuel mixture is too rich or too lean.
Water Pump
Unfortunately, water pump failure is a common occurrence with all Duramax engines. In the case of the LB7 engine, coolant leaks are an issue because the water pump seal can be defective. Naturally, if you’re Duramax is leaking coolant, the engine will overheat. This is just one sign of water pump failure. Other signs include visible leaks, the need to add coolant frequently, a noisy water pump, and radiator steam.
Fuel Filter Housing/O-Ring
Another common issue with the Duramax LB7 engine is found in the fuel filter housing and the o-rings. This engine has an injection pump installed, which is a high-pressure fuel pump. The fuel lines are known to leak because they are unable to withstand the fuel pump’s pressure. The o-rings are also known to deteriorate, and this allows fuel to leak out of them. You may notice engine performance issues if fuel is leaking.
Head Gasket
Nobody wants this problem in any vehicle they drive, and, unfortunately, the Duramax LB7 is known for it. If you’ve ever blown a head gasket, you know how devastating this can be. The head gasket design in the LB7 engine is known to be ineffective in resisting the pressure produced in the combustion chamber. Consequently, it’s easy to blow a head gasket when you drive any of the models listed above.
Finally, Duramax LB7 engines are known to overheat when they are towing loads. This design flaw can make using your work truck a huge problem. Stop by Moose Jaw Truck Shop in Moose Jaw, SK, if you’re Duramax is giving you problems. We have vast experience in repairing these engines including addressing any of the issues listed above.
