Happy Thanksgiving Bill,
Sorry I am writing you on Thanksgiving but I just noticed this issue. I have a 1964 Lincoln Continental that has 55k original miles on on it. I have owned it for around 18 years and drive it once a week fall through spring seasons. Today I heard a loud tap and traced it to the valve cover, after the engine warmed up it stopped and did not return on my 30 min drive. I was hoping you could tell me if you think it’s something that requires my immediate attention or it’s normal for an engine this old? I appreciate your feedback and hope you are enjoying your day.
Greetings Vinnie –
Some of these tapping sounds can be easy to fix or they could be an indication of a more serious problem such as a sticking lifter or an oil pressure issue. What you are describing can also be caused by a slightly LOW oil level in the crankcase. Be sure to check the oil level before proceeding further. Assuming that the oil level and pressure are both ok and that the engine has been maintained with oil changes and the oil is clean I would start with the following. When the engine is cold remove the valve cover from the noisy side and start the engine. This will allow you to trace the tapping sound to the exact valve and lifter area that is causing it before the engine warms up and the sound stops as you describe. At the same time a bent push rod or damage at the rocker to valve area could be visible. An engine with good oil pressure will supply plenty of oil to all of the moving parts for proper lubrication and some oil may even splash and will need to be contained with the use of a temporary splash shield for this diagnosis.
If you are inexperienced with this type of work Vinnie you could discuss it with a good engine shop and possibly have them do it for you. A good engine mechanic will easily locate the problem for you and be able to advise you further. We hope that you also enjoyed a nice Thanksgiving as well.