car engines

[gaurapms]

my car engines which is only 18 months old has developed a rattle on start up for about 1 min but the dealer says that it is normal any ideas?

[toolman]

Check you're using the right grade of oil. with modern engines, instead of mechanical tappets, these use hydraulic valve lifters which rely on having oil in them to open & close the valves. Too thick an oil means it takes time to fill these lifters when the engine's cold hence the rattle . Many modern engines use 5w/30 or similar.