The thermo-porcupine used on the 2.6L and 2.0L is thankfully not used on the 3.0L.

I'm pretty sure he's talking about the thermo switched valve at the top/front of the water box - breakage is common on the 3.0L with heat and age.

Frank

'89 [color:"white"]G-Raider[color:"white"] [color:"black"]Supercharged 3.0L, MegaSquirt 2, lockup A/T, 2.5" exhaust, 172k, Cibie H4s/Oscar SCs, Hella Micro DE fogs, Cobra CB, Superwinch hubs, LSD rear/Aussie Locker front, Bilsteins, Lifeline AGM, Rust-Oleum