[skip11and1]

I was just thinking it was a good preventative measure when hitting the trails or mudding. Maverick I guess you would right a vent wouod be better

[mogo116]

@freeskier why not?

[mogo116]

@maverick I have the hyline offroad hood vents on mine they don't do much except melt the snow in the winter I feel the hot air coming out of them but never saw any movement on the gauge as far as mods I have a bbk62mm tb aem intake banks headers magnaflow cat and banks cat back nothing crazy but gave it alil more pep but also why is it bad that I am running so cool? I always thought the cooler the engine runs the less likely the engine would be prone to damaging it self compared to over heating

[Maverickxeo]

Originally Posted by mogo116

@maverick I have the hyline offroad hood vents on mine they don't do much except melt the snow in the winter I feel the hot air coming out of them but never saw any movement on the gauge as far as mods I have a bbk62mm tb aem intake banks headers magnaflow cat and banks cat back nothing crazy but gave it alil more pep but also why is it bad that I am running so cool? I always thought the cooler the engine runs the less likely the engine would be prone to damaging it self compared to over heating

Engines run richer while cooler; and that means more carbon build up.

[freeskier93]

^Yep, and more fuel consumption.

Your oil is also running thicker than it should. The engineers who designed the cooling system and engine know what they are doing. You don't want too run the engine to hot or too cold, it needs to be just right. For pretty much all car gasoline engines 210* is just right.

[Jerry Bransford]

The engine was designed to run at its normal 210 degree temp and the engine computer was designed around that temp too. Running it cooler will, as stated above, cause the engine to run in its warm-up cycle too long which will cause it to run richer which worsens mpg and performance. Not to mention in cold weather, running a 160 or 180 degree thermostat won't allow the engine to ever fully warm up. Not to mention an engine that isn't fully warmed up to 210 degrees, or close to it, won't pass the smog tests of many states. Our TJ engines just don't run as efficiently at cooler temps.

And being able to turn an electric fan on and off isn't going to help it run cooler since the mechanical fan is already fully engaged when the engine is fully warmed up. And it would take a much bigger than typically installed electric fan to equal the air flow (CFM) produced by the TJ's mechanical fan.

[TJJP77]

Originally Posted by freeskier93

^Yep, and more fuel consumption.

Your oil is also running thicker than it should. The engineers who designed the cooling system and engine know what they are doing. You don't want too run the engine to hot or too cold, it needs to be just right. For pretty much all car gasoline engines 210* is just right.

Cylinder bore and piston ring wear also go up when an engine is run below 180 degrees.

[Sundowner]

Originally Posted by mogo116

I have the hyline offroad hood vents on mine they don't do much except melt the snow in the winter I feel the hot air coming out of them but never saw any movement on the gauge

Well, since nobody else addressed this...

1. If you feel hot air coming out of the vents, then that means they're doing something: exhausting hot air upwards.

2. Your TJ's engine is not air-cooled...it's liquid-cooled. The gauge that measures the temperature of the coolant is doing just that: measuring the temperature of the coolant. If you had an ambient air sensor under your hood, you would likely see a change in the under-hood temperatures. You would have to change your thermostat - which you did - in order to make a coolant-temp gauge read differently.

3. The engine is going to run at 210 - unless the thermostat is changed - regardless of ambient temperature, all other things being equal. In the middle of summer, it runs at 210. In the dead of winter when it's 70 degrees colder...210, again.

4. The purpose of a louvered panel in the hood is not to make the engine run colder. The purpose of a louver is to allow hot air to escape from the engine bay, and this escape path allows ancillary areas to remain cooler than they would should it not be present.

[skip11and1]

Does anyone know why my XJ had one? I thought the motor setup was the same thats why i thought my TJ had one. I've only had ot a couple weeks so I havent really looked Into everything has or doesnt have. I just know my XJ had an electric fan that kicked on when the ac came on or if the temps got a little hot.

[Jerry Bransford]

I don't remember my '89 XJ with 4.0L engine having an electric fan. Maybe you were heaing the fan being kicked on by its thermostatic (viscous) fan clutch which can sound like an electric fan turning on.

[geiman]

Originally Posted by Jerry Bransford

I don't remember my '89 XJ with 4.0L engine having an electric fan. Maybe you were heaing the fan being kicked on by its thermostatic (viscous) fan clutch which can sound like an electric fan turning on.

My friends 01 Cherokee has an electric fan in addition to the mechanical fan as well, and I believe his 94 might have one too, but I'm not sure if it was stock or not. His 01's electric fan was though

[skip11and1]

No I definitely had both in my XJ cause I had to replace it and the radiator withn a couple months of eachother.

[Mywrangler94]

The XJ's have both because....the radiator is way too thin. No such fan to cover the cooling area of the radiator. It's rectangular.....YJ...TJ....have a square radiator. Hence the one large fan.

[skip11and1]

Oh got ya makes sense

[77351wcj5]

I'm just glad my TJ has a factory electric fan setup, I sure wouldn't want any loss in power from a belt-driven one!