Miata 1.8 CAS O-ring change
The O-ring in The Cam Angle Sensor in Miata engines likes to turn hard as brick and leak oil. In the 1.8-liter engine, the CAS is in the exhaust cam and the oil leaks on a heater hose, convenently out of sight. Mine sprang a leak at an autocross.

I had a lot of help from
www.miata.net/garage/cas_oring.html
but their photos are of a 1.6 Miata which has a simlar CAS on the intake cam. About halfway through this job, I figured I should take pictures of a 1.8.
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