Q: 1991 300zx with 153k has a loud sounding head seems like previous owner ran a thinner oil. I heard running a thicker oil will quiet a motor down so what weight should i use.Car runs strong thanks
A: Please remember that motor has gone 153,000. Find out just what the previous owner used and try to use the same weight grade and brand.. If your motor was run low on oil and you continued to drive you may have damaged your used car. Know when your last timing belt was replaced? 18 year old car. Thicker oil does not necessarily make the engine quieter thick oil may not flow around motor parts quick enough on cold starts. New owner your car is not used to multiple drivers are hard on cars. Each person has there own style. Your car will run well on 10 wt-40 wt motor oil 5 wt-30 wt in colder climates. Don't use the synthetic stuff unless that is what the previous owner used. And if trying to decide if I want the Mobil One make sure you motor does not have any leaks first. Synthetic oil will leak out worn engine seals and gaskets much faster.