I bought a Corolla 1,6 Advance in 2008 owing to its reputation for reliability. The car has now done 67 000 km. My concern is that, when it’s not been used for a period of four or more days, at start-up the engine makes a strange noise. This carries on for about 30 seconds and then goes away. When the car is used on a daily basis, the noise is absent. I decided to take the car to a dealership and a mechanical test was done as required to extend the warranty plan. The Toyota dealership was happy to extend the warranty, as there were no signs of mechanical failure.
Any idea what might cause this? Someone told me the engine oil was drained from the top, leaving parts such as the hydraulic valve lifters dry.
JERRY BEKKER, Midrand
Answer: Our guess would be a valvetrain noise owing to the hydraulic valve lifters not taking up the excessive valvetrain clearance as they should after start-up. A moment’s soft clatter is not ideal and should not cause damage, but 30 seconds sound excessive. This could point to either the hydraulic lifters that are worn with excessive oil leak-down rates when the engine is stopped (unlikely at the low mileage), or an oil-feed problem. We do not know what the dealer’s technical inspection involved, but we would suggest at least removing the tappet cover and inspecting for any damage on the valvetrain (camshafts, lifters, etc.) as an oil-feed problem leads to scuffing of the other valvetrain components (again, 30 seconds seems too long for the hydraulic lifters to fill with oil). Lastly, you should ensure that the correct oil specification is used; the wrong oil grade may worsen the issue.