AaronT
Reader
10/24/20 9:48 p.m.
My '99 Miata is leaking a bit of oil, I'm pretty sure the CAS cover is the source.
After loosening the 3 12mm bolts, prying out the old cover, and popping in the new cover I'm feeling pretty good about myself and how this has went so far. I plopped the ratchet onto one of the top bolts and it's spinning freely, weird. Same thing when I try to hand tighten it. Turns out the bolt snapped in half. The other top bolt has also begun to fail but is still in one piece and is out of the car. I'm hoping I can pull the valve cover and twist it out with pliers, or dremel a slot for a screwdriver, or something along those lines.
Can I get to the bottom half of the CAS cover by pulling the valve cover? Can I grab the appropriate bolt from a hardware store?
AaronT
Reader
10/25/20 10:26 a.m.
Picture added to show the location of the bolts in question. (Picture is not of my car, but it is a different 1.8 NB)
AaronT
Reader
10/25/20 10:30 a.m.
And a pic of the bolts removed from my car.
On the NB those bolts really don't see any load, they're just keeping the oil from coming out. So yeah, I think generic metric bolts would be fine.
How much torque did you put on them?
AaronT
Reader
10/25/20 10:43 a.m.
They snapped/stretched on extraction. The car is new to me so I'm not sure if the bolts have been removed before or were last touched by the factory.
If you take the cap off is a stub of the broken bolt sticking out?
I hope who ever "torqued" those last never touched anything else on your car.
Torque on those is really light. They're easier to break than you think.
Mazda specified peanut butter bolts in a lot of places. +2 for very easy to accidentally overtighten.
Hell, last week I broke one of the M8 trans mount bolts in the RX-7 with a 3" long stubby ratchet.
AaronT
Reader
10/26/20 7:52 p.m.
I pulled the valve cover and the CAS plug cover and the remnant of the bolt only had a thread or two above the block. Fortunately liquid wrench left it loose enough to work out with my fingers so I could get it to the height shown in the picture so I could get some pliers around it. Reassembly went smoothly.
Thanks for the input.
