I think max power tends to come with 165F thermostats....though that renders the heater far less effective. Thats how it used to be anyway....performance at 165F.
Think I heard that lowering the engine coolant temp is not as simple as a thermostat swap.
Has anyone successfully lowered their coolant temperature to a level that increases performance a bit?
bad idea, leave the 195 deg thermostat in there. nothing to be gained by messing with engine run temps on a computer controlled engine, it will always think the engine is running below temp and set the a/f mixture too rich.
I think max power tends to come with 165F thermostats....though that renders the heater far less effective. Thats how it used to be anyway....performance at 165F.
210 seems to be the happy place for the 2.5 and 4.0 - I can't comment on the newer engines. It can be 12 outside and the engine runs at 210 - or it can be 112 and the engine runs at 210. I've cut vents into the top of my hood to help with some of the ambient heat buildup when driving slow but no proof it does anything but look cooler :redface:
Yet other vehicles are set to run at a lower temperature. I have heard that Jeep did this to increase the effectiveness of the heater. Makes a bit of sense considering all the rag tops and potentially harsh environments.
I wouldn't mess with it. The engine is computer controlled and switching something like that will just make the engine run worse since the computer will always be trying to correct the incorrect part.
Also, by running a lower thermostat you may actually hurt the performance of the cooling system. I went through this with my 1983 Cutlass recently... I had been having trouble keeping the engine cool, especially in the hotter months in Southern California. Factory required a 190° thermostat but I ran several others down to the 160s and it would still get too hot. After some research I put a 190 in and it ran a consistent 210 even with the AC on with 4 people in the car on a 100° day.
The reason for this is that your cooling system needs time to cool the coolant. If you're running a thermostat that is too low your system will stay open and constantly flowing coolant. As it does this it will gradually build heat from the block and become less and less effective. With the proper thermostat your coolant will cycle and cool your block, then the thermostat will close. When it closes a good majority of the coolant is in the radiator where it cools substantially. Then it will open and repeat the cycle. By allowing your thermostat to close you give your coolant time in the radiator to cool down and more effectively cool your engine.
So TLR... leave the stock thermostat because your Jeep will run better.
I suspect you have something else going on, perhaps fuel delivery rated that is causing your issues.
The easy way to think about the cooling system is the thermostat controls the low end and the radiator/fan/fan shroud/grill design control the upper end.
The thermostat only opens when the temp gets high enough and the system depends on the other bits to keep that temp under control. If the system has enough excess cooling capacity to over cool, the thermostat will close to slow down the flow and bring the temp back up to operating temp.
It typically can not as you suggest, do the inverse and cause more heat with a lower thermostat. While what you said sounds perfectly plausible if one isn't paying attention, it really isn't how thermostats work.
I had a high school hot rod in the 70's. Everybody wanted one back then. My readings had me looking for a 165 degree thermostat. I was unable to locate one.
Things have changed. Big difference between 165 and 210. Big difference between 350 hp and 150 hp.
The only reason to run a 165 is in a boat to keep the salt from solidifying in the engine.
My 97 TJ the temp needle sits directly on the 2 of 210* or at 195* The gauge on the dash and my wife's meat thermometer sitting in the radiator show 195*.
If you have a heat problem, that's a different story, clogged radiator, bad fan clutch, bad thermostat,
Whatever you do, don't get a thermostat advertised as "Fail-Safe".
Keep in mind if your Jeep has a 195°F in it now and it's running too hot, like above 215° on a regular basis, installing a 180°F won't do a damn thing for you. The advertised temp is where the stat starts to open, and it's fully open by ~10°F higher...so a 180°F and 195°F are both open the same amount at 210°F....
I have been told that it is designed to run at that 210 TEMP no matter what and it seems to do that.. I flushed the coolant refilled then put GenRight louvers on the hood and an auxiliary electric fan and no change.. The louvers let the engine cool off quicker when idling but at Freeway speeds its always 210 or a little higher.
If you use a scan tool to monitor the exact temperature, you will likely find out that it does not do that.
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