Has anyone ran a 3.9 L V6 dakota with no t-stat. I have a 180 in now. I'm in NC, so I want to remove
9 Answers
Unprofessional opinion - keep the t-stat installed. If you have cooling problems, maybe you want to correct that instead. Maybe the current t-stat is stuck shut and needs to be replaced? At the very worst, "gut out" the t-stat (remove the valve, spring, etc) because completely removing the t-stat causes coolant to flow through the radiator too quickly, and you eventually will overheat..unless you don't drive the truck long enough to reach that point.
littlehorn answered 16 years ago
modern vehicles are meant to reach a certain temp and maintain that in order to optimize fuel economy and engine performance. Running without a thermostat will cause the engine to stay in "closed-loop" mode and run a preprogrammed fuel/air mixture. Fuel economy and performance will suffer. It's not like the old days where you could run without one in a warmer climate. Keep it in.
Thanks, I installed the 180 t-stat last year and it opened around 180. The spark knock pretty much went away. It is irritating me now on the 100 degree days. I think I will install another 180 stat and see if it helps. Cooling system is clean with no sludge after 147K miles. Anyone hear of a coolant designed to help keep the temp lower?
If you remove it, it will definitely throw a code and the engine will take an incredibly long time to reach operating temperature. you need to have a t-stat..... stock one was 195* so the 180 is a definite improvement, but don't remove it or go any lower than 180*
you may be able to put in a 160 deg t/stat but i bet it will set the cel. i would suggest a 180 deg t/stat and drill 2 1/8 inch holes in the base of the t/stat in the flow area not the sealing area, it may help to keep it cooler, spark knock on these veh was directly related to carbon build up, also sometimes a cracked head will allow coolant into the combustion chamber, to a leakdown test on all cylinders, also proper routing of the plug wires with a very good 8mm wire and good plugs, also use a name brand distributor cap and rotor, also phasing of the rotor to the distributor cab is needed, this is called sync signal and is best performed by a dealership. in addition the lower intake plenum gaskets are prone to sucking inward and allowing excessive oil to go in the combution chamber causing a pinging, remove ari cleaner and look down the throttle body with a flashlight, if it looks like alot of fresh oil in the bottom of the pan, remove intake and installed new gasket (gasket only no sealer) on the lower pan. a combination of any or all of these items may be needed. check intake 1st. hope this helped. need more info send message directly to me.
If you have a knock then changinthe thermostat is not gong to fix the problem. You need to run a higher octain gas or swap motors. Do not go lower than 180*F thermostat. The motor will take forever to warm up and will suck in gas like no tomorrow. diag the knock problem first.
Removing a thermostat will not throw a code. There is no electrical sensor with the thermostat, just a temp sensor in the radiator. As previously stated, removing a thermostat is a bad idea. It is possible to cause overheating, as the coolant doesn't have enough time to cool down while in the radiator. Are you having an overheating issue? Are you trying to do this for performance (it won't really do anything on a stock engine)?
removing the t/stat will throw a code, the code description is (engine cold to long) the sweet spot is aprox 170-180 deg, i know for a afact a 180 t/stat will work i have done it myself many times, i currently own a durango r/t with a 180 stat in it, it does run cooler and it does help with spark knock slightly because it runs the injector pulse width longer applying more fuel. i have been told a 160 will work sometimes, i have not tried this myself, if its in the warmer states. n/c being one of them i believe it would work.
^^^ Like He said, if you remove it or go lower than a 180 it will absolutely throw a code. The engine will take too long to reach operating temp