Water Pump Housing Shims - When are they needed?

[infernosg]

Originally Posted by FC Zach

Did you measure with or without the housing gasket?

The gaps were checked with everything installed and torqued "reasonably tight." Without the shims I had complete contact all the way around at the housing-to-iron interface. Without the shims a I did have a small gap at their location (<.005 in.) but I think this would disappear when the housing was properly torqued down.

Mazda does list another P/N for the shim (there's a VIN split for the S4) and perhaps it's a thinner design. I may order those to check in the future since I won't be starting the engine for some time and it's pretty easy to install them.