Off Roading Forums banner
1 - 6 of 6 Posts
G

·
Discussion Starter · #1 ·
I have a 79 CJ7 with a 4 inch susp, and 33 BFG muds. It seems to run at about 210 whenever i go out trailin, and soem times even to 215-220. This kinda concerns me. Any of your fellow jeepers have any advice. I can do alot of stuff but this cooling business is all new to me. Thanks alot, because i know this sounds dumb.....Thanks Matt

 
G

·
Discussion Starter · #2 ·
try running a cooler thermastat, a bigger radiator (more cores) or a high volume water pump, also try electric fans.

 
G

·
Discussion Starter · #3 ·
Ok...a quick primer of cooling systems.

First, unless your thermostat is bad, putting in a cooling one will not help. Assuming its a 190 degree one, its already open at 210 degrees. Also, water boils at 212 (at sea level)...and with a properly maintained cooling system that can go up to 16PSI, your water won't boil until about 240 degrees...hence, as long as you stay below the boiling point...your usually ok...though continuous operation at 240 is not the best thing. Lets assume that your gauge is accurate...then 220 under low speed, heavy loads is about normal....add in the factor of higher altitude (thinner air), and 220 is actually about right.

Before you worry about your temp you need to look at all the variables. What is your normal temp when driving on the fwy and in stop and go traffic? Stop and go traffic on a hot day should give you a good baseline to judge your engine temp. Also, does then engine feel hot?...i.e., steam coming out?...running rough? If not, then once again, your ok.

Now for solutions. If you have a 79 then the thermostate is most likely a 180 degree model. Don't go cooler, it won't keep you cooler, but the engine will not run as good and in winter time it will be hard to heat up the cab....thats assuming you have the top on....but then, its a jeep...who needs a top.

Next...is the fan shroud installed?...if its gone then that is most likely the cause of your higher temps....the fan to too far from the radiator to work properly without it. When is the last time you flushed the system?...also, a 50/50 mix of water/antifreez will give you the best heat transfer and provide good corroision protection.

No need to add hi vol pumps and extra fans if the original stuff is working right. One last thing...did you drop your gear ratio's when you put on the 33"'s...if you have stock gears then you are really putting the engine under strain at low speeds....at a min you should have at least 4.11 or 4.27 gears..I'm running 32's with stock gears and I'm pushing it already....(for xmas I get new 4.27 gears...i have such a wonderful girlfriend)....

Let us know how it turns out....the feedback is good.........John



84CJ7
 
G

·
Discussion Starter · #4 ·
That isn't a problem if it is running 210 degrees. Water boils at 212 degree, but with a 50/50 mix the boiling point rises. The 180 thermostate will not do much of any thing to cool the Jeep down, trust me I've tried. A thicker radiator can also make the engine run hotter since the air can't get through as fast as a thiner core radiator. If you really want to do something you could add electric fans to get more air flow. My 1980 CJ7 runs 210-220 on the street and on hard slow trails it will run up to 270 degrees. The only addition that I have added is an over flow can so I don't lose fluid. Also I change the oil and use synthetic just for more protection eventhough it doesn't keep it any cooler.

Tim Springer
1980 CJ7
 

·
Registered
Joined
·
6,394 Posts
/wwwthreads_images/icons/smile.gif Oh, Depidee Dog....you Dog you! Having a girlfriend like that! And a Jeep too..../wwwthreads_images/icons/laugh.gif

CJDave
 
G

·
Discussion Starter · #6 ·
Unless I can't read, I think no one mentioned the obvious, how's your fan clutch, is it working?

Brad (from the 4 Wheeling center of the universe, 4 corners USA)
 
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top