[jmatta]

I replaced my t-stat with the LN low temp unit a year/half ago, without replacing the water pump. Wish I'd known of Raby's recommendation to replace the pump every three years, because now I have to do the coolant project again this spring when I do the replacement.

To answer your question, you can R&R just the t-stat, but if your pump is original (like mine) or older than three years, do them both.

And don't use brandX coolant...the Porsche OEM stuff is cheap insurance.