New to jeepin questions

[dwijen]

Hi, I'm new to the forum, and somewhat new to jeepin. I bought a 91 Cherokee Laredo a couple months ago. Stock, 2 door, 48,000 original miles, really nice condition, tow package. I really love it. I bought it to pull a small sail boat, and do a little off road stuff. I'm not much of a mechanic, and I still don't know exactly what I have here. I hope I can get some help with a couple questions.

First, I've noticed that the engine runs pretty hot pulling the boat. It will go right up to the red line. I've seen some postings about a single core, verses a 3 core radiator. How do I determine what kind of radiator I have without tearing things apart? Looking it over, it appears that there are 2 radiators. I'm assuming one is the air conditioner condensor, and the other is the engine radiator, but since it has a tow package, I thought I would see a seperate transmission cooler. There are a couple lines that run from the transmission to the radiator. Does the engine radiator do double duty? Any suggestions on running a little cooler without having to swap the radiator? (The electric fan seems to work fine, and I don't see any signs of problems.)

I have the 4.0L engine. The prior owner said that he only ran premium fuel in it. The book says that you can run regular, and consider running premium under heavier loads. I've tried regular and premium, and cannot tell any difference, heavy loads or not. What kind of fuel do most folks run? Is it worth $.20/gal more to run premium?

I'm thinking of doing a small lift. I gather that I can do up to 2" pretty economically, without a major fuss. Any recommendations on a good, inexpensive way to get started with this?

Thanks for you help.
Dwight

[Chris S]

If you are having overheating and both fans (mechanical and electric) are spinning then yopu have a problem somewhere. Try these in order until the problem goes away
1. Cooling flush/have your rad checked
2. Thermostat
3. Fan clutch
4. Water pump

The OEM heavy duty rad should be adaquate. It is two row and does a good job. If your towing package is stock then you should have the heavy duty rad. If not then you have the useless single core rad.

if you don't have a tranny cooler then add one right away. It will reduce the load on the radiator and extend the life of your tranny.

A 1.5" lift and 30s is a nice compromise between getting some height and losing power. Spring spacers and longer shackles are cheap and easy to install.

[XtremeXJ]

Just thought I would chime in and say Chris knows what he is talking about and offers great advise as does his web site. I refered to his site several times while building my XJ...http://members5.clubphoto.com/robert370569/XtremeXJ/photo2.jpg?6249
Ty Chris and Good Luck dwijen!!! XXJ

[Timmy]

I have also tried premium in my '96 4.0 HO,but after looking and finding that a 4.0 only runs a pretty low compression ratio I see no reason to run a premium fuel even under load, I have had no problem with mine under load with 87 octane, and I wouldnt think that a small sailboat would be that much of a load especially with a towing package, maybe an extremely heavy load would benefit from a higher octane fuel, but I dont really see the need myself, your jeep is made to run on low octane fuel. Happy Jeepin

[satan]

Not a 100% fool-proof check (but will determine if you have been stuck with the single core radiator):

See how much of the end-tanks are exposed on the sides that face each other (like the distance from the ,as installed in the vcar, front of the tank to the front surface of the radiator fins. Look also at the distance in the rear (tank to fins) .

The spacing on the two and three core radiators is such that there is very little difference between tank and fin. The single core, on the other hand, has about 1" of "blank" space on the tank (I've see this a number of ways, most often just the side of the tank showing toward the front edge, as mounted, on the side of the tank; other installations haave the single core more centered on the tanks leaving more than 1/2" of each side of each tank sticking forward and aft of the fins.



As mentioned, adding an aftermarket transmission cooler is a must for all XJs, especially if you're gonna move anything with the car. (there's precious little mounting space in front of the radiator where the cooler will have to mount - look before you purchase... It's also a good idea to mount the tranny cooler on the dpassenger's half of the radiator (IMHO as far to that side as you can) allowing it to be full-time cooled with air drawn by the engine's mechanical fan and to minimize the impact on the rest of the cooling system (only pre-heating the air passing through the hottest water).