When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
What is this hole in the engine between the 2nd and 3rd spark plug
While replacing my spark plugs, I saw there is a hole between the 2nd and 3rd spark plugs and it probably takes a screw that is missing. (see pic below)
The pic is taken after removing the second coil. But that hole in the metal is not the hole for the second spark plug. It is between the 2nd and 3rd plugs (this pic is taken from about 45 degree angle to the vertical). Any idea what is that for? Last year, the Mazda dealership replaced the valve cover gasket, and I wonder if they missed putting a screw in.
This is 2012 Mazda 3, with non-skyactive engine, 2.0L.