AboutMp2 Expertise I prefer to answer questions relating to the Miata since this has been my area of specific
expertise since 1991. I can answer questions relating to the other Mazda models however
some limitation of expertise may reduce my accuracy.
Experience Mazda technician since 1987, shop owner and specialty are regarding the Miata since 1991 covering mechanical, electrical, trim and body. Specializing specifically in drivability concerns.GKHS 1985, BVC 1987, MNA 1989, ASE Master Technician Mechanical 1995, ASE Master Body/Paint/Collision 1996
Education/Credentials GKHS 1985, BVC 1987, MNA 1989, ASE Master Technician Mechanical 1995, ASE Master Body/Paint/Collision 1996
Question My Miata has a real load valve clanking noise and has for a year or more, it seems to be gettin louder. Is this an indication of a needed valve job? If so in idea on the average costs of such a thing?
Answer 94-97 model Miatas are prone to getting air bubbles trapped in the lifters and causing hydraulic lifter collapse.(heard a a clacking or clicking noise - usually without a drive ability issue) The root cause is the type oil and filter you use. I recommend either a Mazda filter or a K&N (1008) and the use of Valvoline full synthetic 5w30 in cooler climates and 5w-40 in warmer ones. This combination will reduce if not eliminate hydraulic break down due to air.
The problem in short is each time you shut the engine down you set the lifters up for air intrusion. As gravity pulls the oil back to the pan and empties the internal oil galleys air takes it's place. When you start up the engine air is forced in advance of the oil into the lifters were it can get trapped until purged by RPM's. The solution is a high grade oil that flows has good suspension qualities and bonds on top of an oil filter designed to limit back flow. The above should be your remedy.
If not, internal lifter issues or other wear may exist, you should have pronounced drive ability issues/symptoms with valve or lifter failure due to mechanical wear. As for track record, if the car has been maintained well, not overheated or run hot and has say under 130k you should not expect upper component wear or service to be due.
