170 degree thermostat options

Hey TW.

I was about to change out my Thermostat as part of a 100k service on my 2014 4.0l.

I'd like to go with a 170 degree stat to help with a very slight spark knock under load. It starts and then goes away when the sensor catches it. Its not much of an issue but if a slightly cooler stat would help, I'd like to give it a try.

Does anyone make a 170 degree stat that will work in the stock housing or is the URD kit the only way to do this for second gen?

https://urdusa.com/urd-170-performance-thermostat-for-1gr-fe-4-0l-v6/

I know that Toyota sells the housing and the stat as as a single unit and that you can get a 160F pretty easily. From what I've read, 170 seems to be as low as you would want to go. Just curious what other people have done.

BTW I read the thread by the guy was selling the billet aluminum ones. Seemed like a lot of bad experiences so not going to do that one.

https://www.tacomaworld.com/threads/billet-aluminum-thermostat-housing-for-4-0l-1gr-fe.781648/

Thanks

 

I wouldn't reccomend going any cooler than the stock 180F thermostat as operating temp on these as far as the ECM is concerned is 175F, things such as idle learn don't happen below 175F also fuel economy will be worse.

Really no need to replace the thermostat if it's working correctly and not leaking, they rarely fail.

I doubt running a cooler thermostat would help anyway, there is a calibration update to address spark knock on 12-14 trucks.

 

Have you verified the knock issue using something like an OBD2 reader? And what about using different/better gasoline?

 

Mishimoto makes one as well

 

Stock is 190-195F. Hot/running coolant temp needs to be above 180F to prevent excessive cylinder wear. If you have an engine knock you need to find the source, and it's not 190F coolant.

 

Actually stock is 180F on 2nd gens.

 

dont!
CEL will come on.
Take it somewhere to figure out your cause for the cause of the detonation...
Can be anything, need to look at PID data & isolate the cause.

Im not certain on your particular Toyota but alot of pam's strategy's will monitor engine running cold & throw a P0128 code...

 

Thanks for the replies.

It's definitely spark knock. I am running 93 octane and the Overland Taylor Torque Tune which was explained to me to be based on the most recent Toyota flash so it should have the TSB changes in it. It only happens in warmer weather at certain RPM when I am really on it and then only for a moment. The truck is in really good shape has no other issues. The pinging is really very slight when it it present so I'm not trying to fix an engine with major issues with a colder stat.


My understanding based on what I've read on TW is that the stock is 180 F, 160 is too cold but easy to get, some folks have reported good results with 170. It could be a total bust but its not that hard to change back if it doesn't do anything. Does the Mishimoto fit in the stock housing? I didn't find one that says it fits second gen Tacomas.

Thanks again

 

https://www.autozone.com/cooling-he...-thermostat-housing-assembly-63460/577311_0_0

I use one of these and the coolant on my ultragauge reads 174-178deg at operating temp.