Crankshaft, timing and valvetrain

Tappets

Tappets (hydraulic lifters and mechanical followers) that sit between the camshaft lobe and the valve and take up the clearance in the valvetrain, so the valve opens quietly and by its full lift, for European and Japanese passenger cars, identified by OE reference.

MONTTRON tappet: a hydraulic bucket tappet standing upright, with its hardened cam face at the top and the oil feed groove around the body

The tappet sits between the camshaft lobe and the valve and passes the lift of the lobe to the valve stem. On most modern engines it is a hydraulic element, a bucket or a pivot that rides directly on the lobe or carries a roller finger follower: engine oil fills a small chamber inside it and takes up any clearance in the valvetrain, so the valve opens by the full lift of the lobe and closes without a gap, quietly, whatever the temperature of the engine. Older and some high-performance engines use solid tappets whose clearance is set with shims or screws.

Tappets fail with oil. A hydraulic element that cannot fill, because the oil is low, old, foamed or the wrong grade, collapses and leaves a gap; the lobe then strikes the tappet at every cycle and the engine ticks, first for a minute after a cold start and then all the time. The hardened face that runs on the lobe wears or pits when the oil film breaks down, and a worn face wears the lobe in turn, which is why tappets are renewed as a set with the camshaft.

MONTTRON tappets are made to OEM-compliant quality and as aftermarket spare parts: the diameter, the height and the hardened cam face of the original, with the hydraulic element and its oil feed where the engine has them, so the tappet runs in the original bore under the original camshaft. The materials are tested for durability and temperature resistance.

The range covers European and Japanese passenger cars. Each reference is identified by the OE number of the original part; send that number and the vehicle identification number (VIN) and we confirm the matching MONTTRON reference.

For availability and OE cross-references, contact us by email.

Frequently asked questions

What is the ticking from the top of the engine?
Usually a hydraulic tappet that has lost its oil charge. It collapses, leaves a gap in the valvetrain, and the cam lobe strikes it at every cycle. A tick that stops after a minute points to old or low oil; a tick that stays points to a worn or stuck tappet, which is replaced.
Are tappets replaced one at a time or as a set?
As a set on the camshaft they run on, and always when that camshaft is renewed, because a worn tappet face wears a new lobe quickly. The engine is filled with new oil and a new filter at the same time.

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