Thermostat Installation

[AYM707]

I've got a Saudi FJ40. Moved to Canada a few years back and I finally decided to put the thermostat back in. Before this, I never had a problem with engine temperature. But generally dont drive it in the winter.

Purchased the thermostat

The on the left is rated for ~73C and I believe that is the original type. The one on the right is rated for 82C and has the jiggly valve so opted to install that one. Installed it in this orientation with the jiggly valve at 12 o'clock.

I am still trying to get the bubbles out, but the engine is running hot. When the thermostat opens; it does drop down to roughly the center, but still leaning more on the hotter side. Have I installed it upside down? Thinking maybe if i install the ~73C rated one, it would open sooner?

Appreciate some input.

 

[charliemeyer007]

Thread 'FJ40 Thermostat Installation How To'

Jun 15, 2017

Since it has been nine years since a thread has been created discussing the installation of a thermostat on a 2F engine, and since I spent about 30 minutes yesterday trying to figure out how to do the installation correctly with the odd gaskets that are included in different rebuild kits, I thought I would quickly show the steps that one would take to properly (hopefully) install the thermostat. (Also the old thread has lost its picture links)

EDIT 8/12/19: Cool Cruisers and SOR have gaskets (upper, lower - thick and thin) readily available. Search on their sites for "thermostat...

• Vae Victus
• Replies: 158
• Forum: 40- / 55-Series Tech

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Find a ramp. Park, set the brake/chock the wheels. Remove rad cap carefully if its hot. Let engine run while looking in the core - you should see coolant surge as the thermostat cycles. A dozen or so surges should purge the system.

Just because you bought a new part doesn't mean its good. I just bought a $10 Amoron IR laser thermometer, works good for checking temps. I like the jigger ones.

So no thermostat to a 180F - yea I'll bet the gauge reads hotter. Tractor gauges aren't all that accurate IMHO; more of a suggestion.

I run a 160F and I curtain off the lower 1/3 to 1/2 of the radiator so it can actually heat up in the winter. One spring right at freezing, I was in low range low pushing mud with the hubs out in the desert. I had to stop twice on a small down grade to first to lower the curtain, then remove it completely or it wanted to run HOT.

 

[3_puppies]

seems the one you installed is too short
there should be a rubber gasket that seals between the top of the thermostat and the inside of the upper housing
right now the thermostat isn't held tight in the lower housing???

 

[Ming89FJ62]

not sure of your year but this configuration is pretty universal for all thermostat configurations

 

[AYM707]

seems the one you installed is too short
there should be a rubber gasket that seals between the top of the thermostat and the inside of the upper housing
right now the thermostat isn't held tight in the lower housing???

After doing a little research, it appears the thermostat i installed (the one on the right in my original post) is typically installed on diesel engines (BJ40) vs petrol. Although both engines are typically running at 80C.

The thermostat does sit in a lip / groove on the lower housing, but you are right, since it is much shorter, it might be pushed up when there is pressure / flow of coolant.

I dont have upper gasket for the petrol thermostat (left), so I will measure the clearance / difference and just cut something from rubber.

 

[73FJ40]

https://www.thewrenchmonkey.ca/auto-parts/toyota/land-cruiser/1973/engine-coolant-thermostat