Aluminum replacement for plastic rear coolant bypass joint

Well, well, well, what do we have here? Yup, a rear coolant bypass made of the proper material for the job. Uses MLS gaskets, too. Built to take the heat!

For the uninitiated, read following links...

https://www.tacomaworld.com/threads/check-your-3-5l-coolant-pipe.531758/

https://www.tacomaworld.com/threads/3-5l-rear-water-bypass-joint-leak.651341/

The good... It bolts up. The temp sensor is correct. The not good... The coolant port for the heater core is in the wrong place. This can be dealt with fairly easily via a hose, by modifying the port outlet, or maybe both. The wire harness mounts are wrong, but look easy to deal with. There is an additional port that will need to be blocked.

Please note, my application is a 6MT, which has no coolant hoses running to the ATF warmer/cooler. I do not know if this will be an issue on automatic equipped trucks.

Pics, more to come.

 

Ohhh shit son! You're a parts finding, ass kickin genius

 

I love scouring parts diagrams for upgrades!

 

Is the plastic one off your truck? You're probably balls deep in your SC so it wasn't too bad to get to?

 

Yes. The transmission is out, too, so easy access. Looks like a PITA from the top.

 

Shiny

 

Oh yeah you're working on the trans too. Does the exploded view show transmission lines for AT?

 

Nice find!

 

Shows the parts, but not certain on exact hose path through the area. Ideally, someone needs to look.

 

Hopefully someone will chime in. If not I'll try to look

 

Just curious what model this came off of?

 

This comes from the Lexus LS and LC 500h, which are hybrids and use the 3.5L 8GR-FXS version of our engine. It has 13:1 pistons and exhaust gas recirculation... needless to say, things run a little hotter on this engine, and this aluminum part was likely installed to deal with that extra heat.

Part #s

16356-31080 Joint, water bypass $119.50
16341-31030 Gasket x 2 $8.85

Lexus may want a vin # in order to supply this part.

Let's get it all mapped out... it isn't done until it's done.

 

What did you get the parts for

 

I think he got them for his truck....


....I kid, I kid.

 

List prices added above.

 

Thanks

 

It's the same for AT as MT, the bypass line goes to the heater core first. It's only after the heater core does the AT vary by adding the warmer before returning to the thermostat.

 

Any updates with this?

 

I have several hoses ordered, so we'll see if there is something out there that will make this swap a little easier. Is your bypass in need of replacement?

 

Mine is liveable right now, I'm just monitoring it as my coolant level is still in the middle but I definitely will need replacement in the future.