# 160* thermostat



## osxPitt (Jan 26, 2015)

Hi all. Picked up an 06 with a rod knock and I'm in the final stages of motor assembly. Been reading all the postings on the 6.0 in the GTO running hot and I live in toasty So Cal so my question is two part: does a 160* thermostat make a noticeable difference in running temperature and will it set a P0128 code for not reaching operating temp soon enough? Thanks in advance for your assistance.


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## svede1212 (Nov 1, 2005)

No. The engine should run fine at stock temps. The 160* stat is a conventional wisdom thing that won't do anything for your car. Programming fans lower has more effect. The engine is made with tolerances for expansion to run up around 200*. You probably won't get a code but you won't be doing anything for your car either.


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## osxPitt (Jan 26, 2015)

Thanks!:thumbsup:


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## Rukee (Feb 8, 2007)

The fuel injection system has a built it "choke" function that runs the engine rich until normal temp. So having a 160* t-stat could make your mpg's drop.


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## HP11 (Apr 11, 2009)

Only semi off topic but are there a lot of postings about LS2 GTOs running hot? I too live in Southern California and have never experienced that with mine.


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## svede1212 (Nov 1, 2005)

Define "hot". Some people think the car running at engineered temps is hot.  Aluminum expands quite a lot as it warms. The engine is designed with tolerances of parts at operating temperatures so too cool of an engine isn't a good thing. A lot of people confuse air charge temp with coolant temp. You want incoming air as cool as possible for density and detonation suppression. The coolant temp affects that a little but it isn't as significant. Like I said programming the fans to kick on lower like around 200* should help everyone.


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## osxPitt (Jan 26, 2015)

HP11 said:


> Only semi off topic but are there a lot of postings about LS2 GTOs running hot? I too live in Southern California and have never experienced that with mine.


From Vararam's CAI sales pitch: 
They “ALL” suffered from heat soak- the Holden /GTO has a sealed engine compartment. This allows very little air in or out, so these cars run HOT naturally, let alone if the motor is built or supercharged! VR-SDR Cold Air
And this topic: 
When it is hot. Our cars are slow. - LS1TECH

So as I put it together just looking for easy tips from the GTO pros. I'm in Temecula, maybe a little hotter than San Berdoo but not much. Good to know you haven't seen any issues.


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## Qnko (Jun 8, 2014)

The thermostat controls the minimum temp not max (assuming its working). The fans control the max. Driving in the city your temp will be controled only by the fans, on the freeway car will run cold. Everything in the engine is designed for higher temp and the oil needs to get hot to evaporate the condensation. Don't get a 160. I had it and after doing some research i switched to 180. And as for power your engine will loose less power heating up the coolant with higher temp stat


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## HP11 (Apr 11, 2009)

osxPitt said:


> From Vararam's CAI sales pitch:
> They “ALL” suffered from heat soak- the Holden /GTO has a sealed engine compartment. This allows very little air in or out, so these cars run HOT naturally, let alone if the motor is built or supercharged! VR-SDR Cold Air
> And this topic:
> When it is hot. Our cars are slow. - LS1TECH
> ...


The Vararam pitch speaks of 'heat soak' which, as Svede stated, has to to with air charge temperatures not coolant temperatures. And, as you say it's a sales pitch. 'When it is hot, our cars are slow'......well, all cars lose some HP as the temperature rises; that still doesn't mean that the car is 'running hot'. That sill has to do with air charge. Important if you're racing, not so much when you're driving on the street. 

My sister in law lives in Temecula. You might have a few degrees on us in the summer but I don't think it matters much when were at 104° and you're at 108°.


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