Billet Thermostat Housing for 4.0L 1GR-FE

Our Billet Aluminum Housing!

We are ditching the factory Toyota spring loaded thermostat for a readily available thermostat at any auto parts store with different temperatures available (Toyota stock is 180°, We will also offer a 160° for those who request it that are tuned/performance) Standard we will be including a high flow 180° thermostat. The thermostat we include is superior to a factory Toyota thermostat which relies on a rubber flap style seal. The thermostat included in our kit utilizes a brass seal design. The thermostat application is for GM 8.1L engines. They are readily available at any auto parts store in stock.

We also ditched the leak prone factory flat style Toyota o-ring. Our billet aluminum housing uses a generic thick gauge heavy duty o-ring that provides a stronger seal then the factory Toyota o-ring. The o-ring for our billet housing is readily available at any auto parts or hardware store as well. We will be listing the replacement part numbers for o-ring and thermostat and make the info readily available to everyone should it be needed.

I have changed a couple dozen factory Toyota housings due to failing plastic/leaking, allowing coolant to leak past the factory o-ring! In a couple cases I actually found the fingers broken that have the job of holding the thermostat in place! One instance lead to a blown head gasket due to the thermostat being sideways!

Other benefits. Our housing does not use the factory Toyota alignment pin which requires a “tang”to be molded inside the thermostat housing. Our billet housing does not have this “tang” resulting in a more free flowing housing. Less pressure and strain on the water pump and cooling system. A small increase in flow through the cooling system has multiple advantages. Internal combustion engines have colder and hotter spots naturally inside the motor, an increase in coolant flow reduces the hot spots throughout the motor. Leading to an increase in engine durability; common head gasket failure is due to these hotter spots inside the engine. With a more balanced/cooler engine temperatures come increased performance. Detonation, knocking, and/or pinging are less likely to occur. When this occurs the computer makes an attempt to protect to engine, it will retard timing and increase fueling, leading to a drop in performance/power/mpg. In tuned applications, timing may be able to be advanced more due to this increased cooling system performance.

And lastly we have a spot located for drilling and tapping our billet aluminum housing at request for an additional coolant temperature sender or switch!

You guys need to see it in person to appreciate the quality. All made in the USA, all US materials by a family owned machine shop located in San Fernando, California.

Normal pricing we will be selling these for $150 free shipping plus tax on the store with thermostat of your choice assembled and ready to install.

I have been given permission from the business partners to initiate a Toyota group & forum $10 off presale. We have our first batch of 100 one week away from being ready.

Please send me a message, text or give me a call! 100% a normal car enthusiast stoked to have his part available to the world!

Cody Anderson
(805)432-1454

$140 free shipping & no tax on the presale!

Factory plastic housing


This is the plastic “tang” inside of the factory plastic housing.

For those interested! The housing will not be listed on the website for some time…
https://stores.unleashedcustommachining.com/
It will also be listed on the eBay store here!
https://www.ebay.com/str/reapercustoms805

Duhhhh I forgot install pics

 

Cool, I like the idea of a aluminum housing rather than plastic. Not sure about giving up a Toyota OEM thermostat for a GM? but your explanation has merit. Will the OEM thermostat work with your housing?

 

So we tried a first version to utilize the factory thermostat, the problem is the factory thermostat is held in place by spring tension and those fingers hanging out of the bottom. It was proving to be very difficult to swap a factory Toyota thermostat into our aluminum housing. We have 3 in use on vehicle currently! No leaks, no operating temperature issues! It is not a GM thermostat we are including, we are including high quality MotoRad thermostat. The design of our included thermostat is just capable of cooling 8.1L of engine, it has no problem taking care of the 4.0, as well as it is readily available part at any auto parts store for $10 or less. It is also a double poppet style thermostat similar to the factory Toyota spring loaded thermostat.

This is how Toyota should have designed the housing, but made it from plastic to save cost period. I have personally seen broken plastic fingers causing overheating issues that were caught before damage occurred. I have heard of multiple cases people are not so lucky, factory thermostat kicked sideways blocking coolant flow, blown head gasket.

 

Thank you for the additional information. Sounds like a solid upgrade. Appreciate your efforts.

 

Got a link for more info or to order?

 

Pm sent!

 

Why not post the link in the thread you started?

 

https://stores.unleashedcustommachining.com/
This is my buddies family owned machine shop located in San Fernando Valley. They are the ones producing the housing! The housings will not be listed on the site for at least another month. They will also be listed on the eBay store https://www.ebay.com/str/reapercustoms805

 

It seems like a solution without a problem.

 

Leaking plastic housing? Broken fingers that hold the thermostat in place leading to a blown head gasket? Those aren’t problems? How many of these vehicles have you actually worked on? I have over 1000 under my belt. I have easily changed over two dozen thermostat housings due to coolant leaking past the factory O-ring. The only reason Toyota did not make the housing out of aluminum or a easily replaceable design is to save cost, period

 

That’s quite the dramatic spin on an uncommon problem that nobody seems concerned about. You just said you’ve only seen it around 2% of vehicles. I get it though, doom and gloom sells, plus it’s a reasonably priced piece of bling to pad that mod list.

 

I'm no mechanic but can this be replaced/installed by an amateur as myself? I plan to keep my 4Runner forever and if this is a good upgrade for preventative maintenance and for long term gains I would consider doing it myself if possible. Thanks!

 

That was my question too. I’ve not seen anything online regarding 5th gen thermostat/housing failures. But I do like the idea of an aluminum housing rather than plastic.
Now I have heard of plastic coolant parts located towards the rear of engine on newer Tacoma’s leaking.
Car care nut states on one of his videos that coolant leaks are generally attributed to not changing the coolant as recommended by Toyota.

 

It is super easy direct replacement part to replace! The cooling system does not need to be completely drained. We do recommend draining some of the coolant to a level below the thermostat housing to avoid a a mess. But it is a good time to replace your coolant if you are due for it!

Remove the radiator hose from the stock plastic housing, remove the 3-10mm nuts securing the thermostat housing to the engine. Remove stock plastic housing.

*Make sure there is no dirt or contamination on the sealing surface on the engine side, clean if necessary.*

And installation is just as easy! Install our billet aluminum housing on the factory thermostat housing studs. Install 3-10mm nuts, install radiator hose, and fill your cooling system!

If it was a race I bet it can be done in 5 minutes or less!

 

Our housings fit ALL generations (4th gen to present!) with the 4.0 engine.

The 5th gen 4Runner’s are not going to be as common with failure due to the newer age. The 4th gen 4Runners are starting to get up there in age and miles! 2005-2015 tacomas, 2007-2014 fj’s, 2007-2014 tundras, and 2003-present 4Runners!

We are targeting to stop all cases of failure with our housing, as well as increased cooling system performance! We have 2 temperature options and the benefit of serviceability should someone decide to change temperatures or the need to replace our included thermostat.

We are looking into the plastic part issues on the 3.5 tacomas currently!

 

They are going fast! 20 presold!!!!

 

Bumppppp! Presale units are going fast! Shipments are starting to go out today!

 

Presale units are gone! Place your orders here!
https://www.ebay.com/str/reapercust...uid=GDApMb0KRH2&widget_ver=artemis&media=COPY


We have 3 thermostat options available!
-Standard Flow 180° (Most vehicles)
-High Flow 180° (Vehicles in high temp climates)
-Standard Flow 160° (Tuned, Boosted, & Race applications)


standard flow design

high flow design

 

https://www.instagram.com/reel/Cket8tPjk3I/?igshid=YmMyMTA2M2Y=

 

https://www.ebay.com/itm/1856465053...DApMb0KRH2&var=&widget_ver=artemis&media=COPY

 

Hi, are these still available? I went on the UCM website but didn't see them there. Appreciate your help.

Anyone install one of these yet?

 

What is the main cause of OE housings leaking? Is it bad design or just age? I just hit 10,000kms (6,000miles) so will likely revisit this thread in 10+ years.

 

Discussed above in OPs post: A plastic vs metal.

 

Probably best to message the OP since they haven't been on since last year. That failure point isn't looking like much of one.

 

"Plastic bad, metal good" is no valid argument in my mind. Metal can easily fail too given the right conditions, hence my query into the cause of such failures he has experienced.

If OP had identified a trend of failures due to a design flaw he may be onto something. But if OP is experiencing failures simply due to the breakdown of material at 300,000 miles, I would find this to be a waste of money considering his item is three times the price of a regular thermostat housing.

 

Hi guys, I’m just wondering if anyone here had installed one is all.

 

@1GR-FE<3R. Anyone else? No clue.

 

His eBay link still has them listed as available, albeit at a higher price of $209.

https://www.ebay.com/itm/1856465053...DApMb0KRH2&var=&widget_ver=artemis&media=COPY

 

No doubt their quality, just if anyone has any experience with them since it is a critical component.

 

I can't speak to their quality, just your question as to whether they were still available.

That being said...at $209 is a tough pill to swallow when an OEM replacement can be had for under $60. The problem doesn't appear to be that widespread as to demand a change. It's nice that's it's offered and I appreciate companies looking to improve on stock parts but if I were in a position that I needed to swap mine I'd grab another Toyota unit and be done with it.