Step by step thermostat removal and install for DIYers

I just did this about a month ago on my 308QV, which uses the same thermostat as your 328. It's one of the simpler do-it-yourself tasks, and I did it twice, since I first used a "compatible" thermostat from a VW Rabbit, but when I still had cooling problems I went with a proper Ferrari thermostat. In my case, the cooling problems were at the radiator, which needed to be cored out, rather than the thermostat after all. Here's the steps from memory:

Put the car on level ground. Remove lower hose from coolant overflow tank in engine bay, drain to a shallow bucket or oil catcher pan. Remember that animals find the smell/taste of coolant pleasant, but it's poisonous.

Remove big connecting air hose from lid of airflow box, then remove lid of airflow box and remove air filter. Stuff a rag over the hole(s) in the bottom of the box.

Remove the three nuts that hold the top of the thermostat housing cover to the block and remove the top of the thermostat housing. You may or may not have to remove the exit hose from the thermostat housing to be able to wiggle it off, exposing the thermostat.

Remove and replace the thermostat and circular rubber gasket that is around the outer edge. If your thermostat is the proper heavy duty one from Ferrari or Ferrari suppliers (rather than using an "almost the same" from Autozone), it will have a small relief hole in the flat disk portion. Rotate the thermostat so the hole is positioned on the highest edge. This is so that any air doesn't get "caught" there.

Replace the thermostat housing triangular paper gasket with a new one. If you choose to, you can put a VERY TINY line of silicone sealant on it (optional).

Reassemble, refill coolant overflow tank to proper level. Open bleed valve on thermostat housing until coolant just starts to come out, then retighten.

It probably took me 45 minutes to an hour total the first time, and maybe 20-30 minutes the second time I did it a day or two later with the other thermostat.

Recheck level in overflow tank, and do the "usual" air bleed proceedure after warming your engine and checking for leaks. You will find that you probably did NOT leave much, if any, air in your system by doing it this way, so there will be very little to bleed off (unless you already had air in the system before the procedure).

 

I ordered the gaskets from T Rutlands in Atlanta (800-638-1444), had them the next business day, just 1 day via UPS ground from their place to mine.