Questions and Answers

Cadillac Escalade Valves Are Tapping Q. I have a 2000 Cadillac Escalade. I started it up in morning and a tapping noise was coming from the engine. I know it's the valves. It only does this in the morning for a little while and it stops. The truck calls for SAE 5W30 weight oil. The last time I had it changed Jiffy Lube put 20W30 weight in it. The instructions say only 5W30 and it must be APC certified.

So if I change the oil with the right weight and add a lubricant like Slick-50 engine treatment will that stop it? Or if it doesn't, what about Marvel Mystery Oil? I heard that is good for stopping valves from tapping. Please send your information on what and how to solve my problem.

Thank you,
Scott

A. Forget Slick-50. You'd do better off putting extra virgin olive oil in your engine. You can try Marvel Mystery Oil and see what it does for you.

What I do is drain the oil and replace the oil filter. Then substitute one quart of transmission fluid for one quart of oil and run that for about 3,000 miles. Then do it again and a third time if needed. If that doesn't clear up the tapping, the lifters will need to be replaced.