piston slap

piston slap

n
(Automotive Engineering) the characteristic sound of a seriously worn piston in a cylinder (usually of the engine of a motor car)
References in periodicals archive ?
Instead of it being located on a crank, the clever design means that the piston slides absolutely vertically on a geared rail so that piston slap is zero.
The pistons have an offset piston pin and extended piston skirt that reduces piston slap and thus engine noise levels, Sugar said.
It is used to take out the piston slap when placing in new rings.
This causes the piston to shift in the opposite cylinder wall just before top dead center greatly reducing piston slap (aka: noise).
When mechanics say: "That noise could be a rod or main knock, piston slap, or a bad lifter.
Among the signals coming from the cylinder are those that result from piston slap, which occurs in an engine because of the changing angle of the crankshaft as it revolves through a full stroke," Lyon said.
Some of the models that may have a Piston Slap defect are the Chevrolet Camaro, Corvette, Silverado, Tahoe and Surburban; GM Denali and Yukon; Cadillac Escalade and Pontiac TransAm.
This causes the piston to shift to the opposite cylinder wall just before top dead center, greatly reducing piston slap.
This has also reduced engine noise, since closer tolerances yield less piston slap at low load and cold start conditions.
Piston slap has been reduced by optimizing the clearances between the single-piece piston and the cylinder and the piston skirt features a molybdenum coating that improves fit within the cylinder.
To lessen piston-generated noise, the piston pin is offset and the Art single-piece aluminum piston incorporates a specific profile designed to accommodate thermal deformation of the cylinder and reduce piston slap.
It can be caused by several different mechanisms, but in engine cooling systems it is most often a result of cylinder liner vibration caused by piston slap and/or combustion pressures.