Where to buy 1JZ 71 degree thermostat?

[ZZT231]

Hello All,

Besides the TRD 71 degree thermostat (P/N 16340-SP020), is there an alternative thermostat I could use/buy as the TRD item is a 14 day wait for a pricy sum of AUD$150 trade

Cheers.

[ZZT231]

The TRD Thermostat replaces: Toyota part number:

90916-03093 (82 degrees)
90916-03126 (unknown)

Cheers.

[131OWN]

Mate PM "max_thrust" SupraForums.com.au he has one he want to sell Part No.16340-SP020 which is 71C

[CrUZida]

Why would you want a 71degC thermostat ?

[chaserbuddy]

nengun sell some like 68 degree ones, and some 75 degree ones or something, why not just stick with the old stock 82 degree...

[ZZT231]

Mate PM "max_thrust" SupraForums.com.au he has one he want to sell Part No.16340-SP020 which is 71C

Will PM him - thanks for that...

Why would you want a 71degC thermostat ?

The engine bay at cruise is running (95-105degC) at idle or stationary for an extended period of time it drops to 90degC, the radiator to a 3rd thicker (than the original one) and there is an engine cover under the car. The termo fans is set to go off at 95degC (Yes they run all the time including Highway driving). The engine is currently fitted with a new 82degC thermostat running Toyota Red Coolent. The heater core has been inspected and flowing properly (no blockages). All hoses have been replaced...

So in theory, getting a 71DegC thermostat would mean the engine would be running at 85-95DegC if all the enviromental caculated factors are correct (and theoretically possible).

Cheers.

[CrUZida]

Got a photo of your engine bay?

Other people with 1J's in MA61 bays don't have this issue.

[cambelt]

A 3 cored MA61 rad is too small for a JZ engine if your running A/C and P/S . When a 3rd core gets added it doesnt make it a 1/3rd more effective , most times the addition of another row may gain 20% more cooling capacity.
If your engine is healthy id opt for a new aluminium rad .
Dave

[JustCallMeOrlando]

I'm with Peewee, fix the real problem, don't bandaid it with a thermostat. Something isn't working properly.

[ZZT231]

Got a photo of your engine bay?

Other people with 1J's in MA61 bays don't have this issue.

It's a normal engine bay with nothing fantastic about it (I'm at work so I don't have a photo at present).

A 3 cored MA61 rad is too small for a JZ engine if your running A/C and P/S . When a 3rd core gets added it doesnt make it a 1/3rd more effective , most times the addition of another row may gain 20% more cooling capacity.
If your engine is healthy id opt for a new aluminium rad .
Dave

Yep, done that too (aluminium radiator)... I do not think I got a 3 cored radiator, got a 40mm thick one (thickest the radiator guys could fit in the engine bay)...

I'm with Peewee, fix the real problem, don't bandaid it with a thermostat. Something isn't working properly.

JCMO, you do have a point that there is something wrong and I'm trying not to do, I have no clue what the problem is... I have installed a large 11" B & M transmission cooler, running a very large power steering cooler (similar to a 4 cylinder oil cooler) too keep them cool. New hoses, using original Toyota fluid... I'm still baffled

Pictures of the radiator (which I think it's not the issue):

[JustCallMeOrlando]

JCMO, you do have a point that there is something wrong and I'm trying not to do, I have no clue what the problem is... I have installed a large 11" B & M transmission cooler, running a very large power steering cooler (similar to a 4 cylinder oil cooler) too keep them cool. New hoses, using original Toyota fluid... I'm still baffled

Clearly you've done all the right things, I'm not saying it's something wrong persay. A lower thermostat isn't a solution to the problem, it's a bandaid. Playing devils advocate, are you sure the gauge and the associated wiring is OK?

[CrUZida]

Are you running a pod filter?
Perhaps the waterpump is losing efficiency?
Maybe there is a buildup of scale on the inside of the head/block?

[oldcorollas]

The engine bay at cruise is running (95-105degC) at idle or stationary for an extended period of time it drops to 90degC, the radiator to a 3rd thicker (than the original one) and there is an engine cover under the car. The termo fans is set to go off at 95degC (Yes they run all the time including Highway driving). The engine is currently fitted with a new 82degC thermostat running Toyota Red Coolent. The heater core has been inspected and flowing properly (no blockages). All hoses have been replaced...

So in theory, getting a 71DegC thermostat would mean the engine would be running at 85-95DegC if all the enviromental caculated factors are correct (and theoretically possible).

Cheers.

i fail to understand your theory.

so.. say you had an 82 or 71deg thermostat..

engine warms up with stat closed.
71deg starts to open at 71deg
82deg starts to open at 82deg...

and then...
The engine bay at cruise is running (95-105degC) at idle or stationary for an extended period of time it drops to 90degC, the radiator to a 3rd thicker (than the original one) and there is an engine cover under the car. The termo fans is set to go off at 95degC (Yes they run all the time including Highway driving).

those temps... 90, 95, 105.. are all higher than 71 and all higher than 82...
so regardelsss of what stat you run, it will be open anyway.

the problem is not enough cooling, or something not right, as opposed to the thermostat (which just makes engine warm up quicker.. to the stat temp.. and then after that all it does is slow flow down IF temp drops near the stat temp.. which it is not doing...)

?? am i missing something?

you say the fans start at 95deg, what temp do they turn off? the temp can only go as low as when the fans turn off when stationary (90deg?), but staying hot during cruise indicates there is a "problem".

do you have any other things in front of the radiator? are the sides of the rad sealed for airflow? (and underbonnet as well), bhg? water hoses not routed correctly?

[allencr]

i fail to understand your theory.

+1 for oldcorollas reply.
I understand that you don't know what the thermo. opening temp. means and its effect on max temps, so I'd say & not guess, that one or more things are wrong but it's not the thermostat.
Also, the fans thermo. switch is located on the engine's coolant outlet - the radiator's upper pipe - inlet, isn't it? It should not be there.
Also, also, there are many thermostats that you can adjust to suit yourself/whatever if you really want to, if they've got a little threaded rod on them that goes into their wax pellet. That TRD thing is foolishly expensive.

[oldcorollas]

i wonder if the design of the tanks in the rad, prevent it from flowing equally across it?

can you get an IR temp gun, and put it on the rad while warming up.. say, measure every 10cm across every 1 minute or 30s whatever?

is the current thermostat not opening? or not opening far enough? or there is air in system? or your temp gauge is out or or?