What is a hydraulic lifter?

The hydraulic lifter is a cylindrical component positioned between the camshaft and the engine valves. Its primary function is to assist in compensating for variations in valve train clearance, ensuring the maintenance of zero lash (the absence of clearance between the valve lifter and the camshaft lobe). This results in quieter operation, increased engine longevity, and eliminates the requirement for regular valve clearance adjustments.

The main responsibility of hydraulic lifters is to transmit the force from the camshaft lobe to the valves.  To keep the valves closed, a small amount of clearance is necessary between the camshaft and the valve, as the metal expands when heated. The hydraulic lifter plays a crucial role in regulating this clearance.

Below is a picture of the hydraulic lifters located inside the engine block (B).

Which generators have hydraulic lifters?

• All models of the Next Generation series feature hydraulic lifters
• For Guardian series, the 14 kW and 18 kW air-cooled home standby models (G-Force 800 Series ~816–817 cc) have hydraulic lifters. The 10 kW and 20–26 kW models do not (they use adjustable/solid lifters).
• See: What Types of Engines Does Generac Use in Their Home Standby Generators?

Maintenance 

While routine maintenance is still necessary for the generator, valve adjustments are not needed on generators with hydraulic lifters.

Identifying hydraulic lifter issues

The hydraulic lifters, although not visible, are a vital component that can experience malfunctions like any other part. Look out for the following indicators:

1. Unusual engine noise: If your engine is producing louder or unfamiliar noises.
2. Engine stalling or misfiring: Instances where the engine suddenly stops or runs unevenly.
3. Decreased fuel efficiency: Noticing a significant drop in fuel economy.
4. Broken pushrods or non-functioning cylinders: Physical damage to pushrods or cylinders causing them to malfunction.
   
   

If you observe any of these signs or notice any other abnormalities, it is advisable to get in touch with your local Generac-certified service dealer. They will dispatch a professional to diagnose the issue and provide the necessary assistance: How Can I Find a Generac Service Dealer in My Area?