Thermostat: 180 or 195?

[user removed]

With the engine at normal operating temp and running check the difference between the temperature of the top and bottom radiator hoses. It should be at least 40-50 degrees or the radiator is not cooling properly. Radiators gradually loose their cooling capacity and at about 10 years age many need replacing (not an absolute depends on many factors).

You can check with your hand if it can be done safely, of with a laser thermometer if not.

Sadly a radiator replacement may actually lower your mileage slightly, but that's better than a blown head gasket or engine.

regards
Mech

[stovie]

comptiger5000 - it was hitting about 230 at stoplights so i decided to get a 180 to make sure you know and even then the thing would start creeping towards the red with the electric fan i had so i reinstalled the mechanical fan and it still starts to creep that way at times but never over 200 now. any ideas on how to better my cooling????? and that was without a/c. i was thinking of getting the 165 to make sure the t-stat was fully open by the time temp hit 180 with the e-fan so i could have optimal cooling????(i get full temperature in 5 minutes or less)

[comptiger5000]

If it's not getting over 200*, it's fine. 200 - 210 is normal operating temp for these. Running colder hurts power and mpg. The 4.0 doesn't like running cold. The V8s don't mind it as much, but it'll still hurt mpg. Colder than a 180* stat is overkill. In the 4.0, stick with a 195*. For a V8, a 180 or a 195* is fine.

It sounds like you need a bigger e-fan. Look into the 2 speed Taurus fan swap. That's what's used (with a slightly different shroud) in the 5.9, and mine stays cool no problem, even with the fan on low.

[stovie]

thanks for the info i took the motor off my electric fan and was thinking of making it run my 22 inch mechanical fan and water pump it says it hits 1760-2100 rpm and i never really go over 1500 anyway but i still want to have it to where i can put the belt back on in case of e-motor failure. i'd like to put it in place of the steering pump.

[comptiger5000]

I doubt the e-fan motor would be able to turn the mech fan fast enough. Also, you can't take the belt off, as the mech fan is driven off the water pump. Removing the belt from it would disable the pump. A proper e-fan conversion with something like the 3.8 Taurus fan that can flow enough air to keep it cool is the best solution.

[morpheous71]

Can you recommend anything for the liberty 3.7-2003. I'm getting water temp's 198-202F, is there something I should be modding to improve mpg's and performance??? Not sure even were the thermostat is on this baby. I know it's possible to disengage some fan and run electrical but I do not understand how that's done and why?

[comptiger5000]

The temps you're running are fine and normal for a KJ. If it's got a clutch fan, you can swap to an e-fan, which will help mpg a little.

[Phantom]

The reason for an e-fan is there is less drag on the motor since it is only on when needed and the engine can get up to operating temp quicker.

The jeep in the first post have you had the coolant flushed and the radiator cleaned? If it has build up of junk it can hinder the cooling ability. Also has it always ran hot or did it just start happening?

[stovie]

i took the belt off my jeep the other day and decided to see how much resistance the water pump had, i flung it with my hand and the thing spun for 15 - 20 seconds. i then put a belt i made only to the water pump then drove around, the mpg gauge at the time was saying i had about a 40 percent increase in fe so now i'm trying to make that setup permanent but i had to put the old belt back on for now, and i want to put my electric motor on the water pump to further the fe gains.