The causes of top end rattle in an engine, often described as sounding like a 'Bag of Nails', are many and varied and often difficult to identify without removing the cylinder head. In the first instance, it pays to consult a qualified motor mechanic to eliminate mechanical causes such as worn dephaser pulleys on VVT units, slack timing chain and even the inadvertent use of cheap aftermarket oil filters without non-return valves, which allow the oil to drain down overnight. Ignoring a mechanical cause of engine noise can result in catastrophic engine failure, so obtain a diagnosis first before trying a chemical additive.
Oil starvation is another possible cause of top end rattle. Blocked or narrowed oil-ways and dirty channels inhibit adequate lubrication to the hydraulic tappets or lifters (HLAs), valves and guides and can also cause piston rings to stick. Flushing the engine with a proprietary flushing oil, like RESTORE Motor Cleaner before an oil change will dissolve sludge, varnishes and gums from the engine, free up stuck rings and valves and open oil-ways to restore lubrication. This is strongly recommended before the use of Ametech RESTORE Engine Restorer.
Where lack of engine lubrication results in increased friction between two moving parts, the friction cuts scratches into the engine metal and this wear causes a loosening as the clearances between reciprocating and rotating components extend beyond the prescribed tolerances. This causes the sort of noises described as noisy tappets, valve train noise and piston slap. Ametech RESTORE Engine Restorer fills the scratches in the friction-producing surfaces with its unique CSL formula to restore the tolerances, reduce the rattles and tighten up the engine.
Some engines benefit from enhanced lubrication when all other considerations have been addressed, in the form of a Super Lubricant and Friction Reducer or a Metal Treatment and Conditioner. They work in different ways, but both types of product will protect the engine on start-up by keeping the engine parts lubricated during shut-down, so that lubrication is instantly available when the engine is started. This helps to prevent that ticking noise that is often apparent on start-up, but disappears after a couple of minutes when the engine oil has had a chance to reach the top of the engine. Ametech Super Lubricant also helps to prevent wear my maintaining oil viscosity at higher temperatures and keeps the engine oil and components clean, preventing the formation of varnish and gums.
For a really superior friction-reducer, choose Ametech Metal-Tec10 for your engine. This is a metal conditioner and treatment that chemically flattens friction-producing metal surfaces to eliminate asperities - the high points and low points that look like a mountain range under an electro-microscope - that cause friction, heat and wear in an engine. Ametech Metal-Tec10 smooths out those surfaces, increasing the boundary film strength of the engine oil; the engine oil holds to the metal surfaces and provides the best possible lubrication during start-up, no matter what the time of year, or temperature. Engine noise is reduced and the engine runs more efficiently, reducing fuel consumption too. If your engine is worn and you need to use Ametech Restore Engine Restorer to fill the scratches, this is best done a few hundred miles before adding Metal-Tec10 to the engine, just the give the Restore CSL particles a chance to bed in firmly first.
Please Note: Only those tappets with an hydraulic oil supply, otherwise known as hydraulic lifters or HLAs, will respond to Ametech's liquid chemical engine treatments. Mechanical tappets do not have an oil supply which is necessary for any of our products, which are added to the engine oil, to reach the moving parts to be treated.