2.7L thermostat replacement - required gaskets?

Edit/update: thanks to an Ebay listing for an aftermarket Felpro part, I've got another OEM number for that second gasket in question (16325-75011). That listing says the part does fit my truck, and an actual dealer's site also says it fits. But Toyota's main non-dealer parts site says it "may not fit". I'm going to go with "it fits". I guess I'll leave the post here in case it helps anyone down the line going through this confusion.


Hey guys,

I have plans to replace my water pump and possibly radiator before long as preventative maintenance. I went ahead and got a new thermostat as well since it was affordable enough.

I'm in a 2006 @ 204k miles. Again, a 2.7L.

My question is, is there only one gasket or two to worry about for the thermostat? The t-stat I got directly from the dealership came with no O-ring gasket around the circular edge. I'm quite certain I need one there (OEM #1632576010).

I do have the FSM, which mentions another gasket (no pic of it though) which goes on the water inlet housing (the metal housing that covers the t-stat, and which the inlet hose slides onto). Watching a youtube vid, the guy is doing a 2010 2.7L and I can see both gaskets. It looks similar in appearance to OEM #16325-0H030, but Toyota's parts website says it "may not fit" my truck. Another site claims it doesn't fit my truck.

The youtube video in question, where this second gasket is seen (not the O-ring one on the t-stat, but the one that goes on the inlet housing - seen at 56 seconds in: https://youtu.be/oG8gEgselms?si=dUqEajwj34Hni_w2&t=53

Can anyone confirm that I do in fact need this gasket, and what the part # might be? Even more confusing is that Toyota's website calls both the O-ring and this other gasket "water inlet housing gasket," when it seems like the O-ring would be more aptly called a "thermostat gasket".

I know from another post that DGXR has done it...maybe he would be kind enough to chime in?

 

Looks like you need the gasket and the seal.

I'd also update the plastic coolant bypass pipe that likes to leak to the steel one if it hasn't been done yet.

 

Did that 7 months ago! I discovered my coolant reservoir nearly bone dry whilst changing my oil - thankfully my engine never overheated. Thought about doing the t-stat then, but was in a rush to get buttoned up. Now I'm ready for a complete cooling system overhaul, just for peace of mind.