Was leaking from the drivers side bottom so I decided to change it, place near where I live had new one for 127.00. During this time when it leaked there was always orange stuff i am assuming that it was rust due to the fact i never used the orange rad fluid any idea where this came from and any problems it could of caused? I also replaced the serp belt with a gatorback since I was in there. Do you guys also recommend that I change the thermostat also 195 deg or 192 deg?

 

hello, welcome, ok if you took out and put in a new rad then dont worry about the orange stuff, but but, if you still want to know, that might be rust but it will be a orange brownish color, but there are also some orange coolants out there, for example my cobalt uses one that is orange..

to find out if you have any more of that color liquid in your system just wait a few days maybe a week and re change your rad fluid just to make sure, not needed I believe..

well if you have heating probs then you could change iit, most people recomend the 190something degrees tstats if your ok on the temp part, if your a lil high might want to go with 180,, but you cant go too low you need certian degree of heat for your engine to work happy and dont run rich

 

Likely that orange crap is rust from the radiator..Now when you changed this radiator did you flush the system out? What I do is unhook both upper and lower hoses and let the lower hang into a bucket then with my garden hose I and spray water through the upper hose.. This will flush the engine out as well..This will clean out the engine and you will ahve all dirty fluid out..Next is hook everything back up and start filling it back up with good 50/50 rad fluid using either a premix or mix with distilled water. Then you shouldn't have any issues with rust and corrosion in the cooling system.

 

Before you hook the radiator up, remove the thermostat housing and flush out the system. You need to get as much of that crap out or it could clog a port and overheat. Now thermostat wise I would just replace it with a regular 180 degree theromostat. Its not neccessary to run a high temp thermostat. The 180 is just fine.

 

JeepersCreepers the XJ's stock suggested tstat is a 195...These engines are designed to run at around that 210 mark..wouldn't a 180 cause it to run to cool? I know on mine it had a 180 when I bought it and it ran cool infact too cool needless to say that was just a small part of my engine troubles..lol

 

180 degrees is the point of when the thermostat opens. But whatever the stock thermostat temperature is it should be replaced with that whether its 180 or 195. Using the wrong thermostat can cuase heating problems. So its just best to replace with the proper thermostat. Im sorry, im not up with my jeep specs yet.

 

No worries I just wanted to make sure there wasn't something I wasn't aware of.. I know many people use a 180 to help keep their jeep cooler but I figure it's better to fix the problem and not mask it..

 

Make sure the rust isn;'t from the propellers on the water pump...

 

yeah and if I were you ill take the WP off and with a small wire brush scrape all the build up, mine had some there and im glad is gone now

 

Propellers are on planes and pumps have impellers. Use distilled water for the refill or get the premixed coolant.

The ECU looks at the operating temperature while it is determining the point to alter the fuel/air mixture. At 195 degrees the ECU goes into closed loop and increases the airflow while reducing the fuel flow to the injectors (pulse width) this improves the fuel ecomomy while increasing the life of the injectors. So you see a 192 degree thermostat (factory specs) is what you want for the best fuel mileage. Stant calls it a 195 degree but it is the same as OEM and is fully open at 192. You are prolonging the closed loop actions of the ECU at cooler temps which decreases fuel mileage and carbons up the O2 sensor and wears out the injectors more radiply.
Hope this explanation makes the ECU's actions easier to understand so you know why the factory was using 192 degree thermostats in the 4.0L engines.

 

Great information and post Blue...Couldn't have said it better myself..I knew it just wouldn't have said it that clearly...Makes perfect sense now.. Also makes a good reason to fix the cooling system and not band aid it..