NBS Thermostat Swap How To

bgray

Stylish Canadian
Mar 17, 2012
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Onterrible, Canada
Here is a brief write up on an very easy thermostat swap with some pictures.
Need 10mm socket,
drain pans
vice grips
wire ties

First off..Here is the new thermostat..160 degree

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Let truck cool and Remove your rap cap to realease the system pressure. When removing the lower rad hose, coolant will want to come out of the rad, but not the motor bescause the thermostat is presently closed. So at this point you need to be concerned with stopping the rad fluid from emptying the rad
I like to keep as much as possible inside, to prevent contamination. I like to take Two small vice grips and put one of each side of the hose to restrict leakage,(however, you can run the risk of collapsing some rad hoses) then after I pull the hose off wire tie it back up to stopp all fluid from emptying.

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Now you need to remvoe the theremostat and housing, and let the rad fluid drain our into pans below the truck..there about 5 litres in there....
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Install new Thermostat, un vice grip, and fill rad fluid...DONZO
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Yes, you should get a tune update for this. We do not recommend swapping to a lower thermostat, as these engines need to run at higher temps to burn off condensation in the oil.
 
Nice write up and for the American folk, 5 liters = 1.32086026 gallons. :crazy:
 
Another thing to add about thermostats: 8.1L trucks have a reputation for losing oil between changes. I was losing 1-2 quarts. I call it losing because it was not getting burnt and there were no leaks to be found. After some researching it seemed that the big block produced excessive heat in the crank case and oil was being vaporized. I made the switch to a 180* T-stat and no longer lose noticeable amounts of oil.

Also, Jenna is right. T-stat swaps were popular with older engines that didn't cool as well as modern ones. A 160* and even a 170* is too cold IMO and will hurt performance and cause excessive wear on internals.
 
Been running lower t stat for 6 years, Pulled my 5.3 apart after my lq9 went in and it was cherry insdie with 70k on it...just some fyi. If you have tuning available it cna be done, but is not required just to clarify
 
Why exactly did you change it to a lower temp? Unless you are really making some heat you did nothing but make the engine less efficient and the heater not work as well. In a perfect world you actually want the engine to run as hot as possible to make the most power and run the most efficient, the problem there being you are limited by detonation, heatsoak, lubrication, and emissions issues. Running colder does nothing but create more hydrocarbon emissions, reduce fuel mileage and power potential. Running as cold as 160* may even be enough to keep it in open loop mode further killing efficiency. The only real application would be if you were running boost, advanced timing, high compression, etc. Even so, with today's technology there are much better solutions than a colder thermostat such as e85/alcohol/methanol/water to reduce cylinder temperatures and reduce detonation, better oils to withstand breakdown in heat, insulated materials in the intake (like the stock plastic intakes), etc.
 
This was done 6 years ago way before I knew alot about LS platforms, my LQ9 has a stock stat...however I posted this how to for further information to this website...

But fuck it, might as well not post anything productive. Its here for people who want to use it, or shit, even for people that just need a walkthrough to replace there Stat.
 
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Thanks for sharing mate. Gonna have to get a new Thermostat since it has been failing due to some leaks from the housing and has resulted to loss of coolant. Easy installation wouldn't be a problem no more.
 
Is this one of those things it's best to replace with an ACdelco unit?

I put an AC Delco in mine when I replaced the water pump. I didn't need either but the pump gaskets were leaking and with my luck I would replace the gaskets and the pump would go out a week later so I just swapped out everything.