Is2k

I was under the understanding that brass/copper was still pretty comparable and is more ideal or is that just old timer talk?

Jim Malcolm

Purely old timer talk... 1970s technology. The only reason to run one is that they can be repaired via brazing.

Is2k

Alrighty, off to autozone then, we’ll see if that fixes anything

Roler

It was a new radiator no?

Before you go and buy anóther radiator: Unless it's significantly blocked already , I doubt that is the issue....brass/copper is fine, mine is very resilient and only ran hot once...when it was blocked for 70% and had 3 leaks according the repair guy. Aluminium isn't bad.

Is2k

Correct, was installed in march of this year. No winch or anything to block airflow and it’s not clogged or anything.

Jim Malcolm

You're also not overheating yet... XJs run hot

Is2k

Not quite overheating but it will and that’s my problem. I know they run hot but not that hot. It’ll sit at 210-20 for maybe 5-10mins then just seem to let go and and it’ll creep all the way up to red.

Jim Malcolm

"Griffin claims that a two-row aluminum radiator with 1-inch tubes will cool as well as a five-row copper-brass radiator with 11/42-inch tubes." from https://www.motortrend.com/how-to/cc...-for-your-car/

The article was written in 2009. Things have improved even since then. You'll be hard pressed to find a dual-row aluminum radiator for an XJ, only "dual-row equivalent". They've implemented the latest-and-greatest technology, namely thinner and thinner tubes as described in that article, yielding better performance out of the basic XJ radiator.

Another thing to consider is that high flow water pump. Some people have claim they work, some people claim improvements going back to a regular one. If you really look at a Jeep 4.0 cooling system, it's a horrid piece. It's a straight 6, what can you do? Compare it to a SBC. Now that's a pump. On a Jeep 4.0, it's more of a stirrer.

Being a 96, you won't have a Temp Sensor for the Gauge on the driver's side back corner of the head, but you may have a plug. Parking nose-down on the steepest hill you can find and removing that plug really bleeds the air.

Have you eliminated the Heater Valve? Did you plumb it up the same way or did you use the 97+ hoses? The 97+ hoses are backwards from an Engineering standpoint. It works well enough, I suppose, but it's technically backwards. If you look at the last pic on the first post, if you fill the Heater Core from the top line, the coolant can fall to the bottom of the inlet cavity, pass through the top core, then fall down the common cavity, leaving a pocket of air at the top that must be pushed down to exit. If you fill it from the bottom, the air pocket can easily escape. I'm not saying the 97+ method doesn't work well-enough most of the time, but when you're chasing issues... Doing it the right-way requires adapting hose sizes while the 97+ method does not. Bean Counters...

https://www.cherokeeforum.com/f51/97...cement-219723/

Is2k

Yea the cooling system in these things a steaming pile, literally haha. All the way from renix to HO and it’s especially bugs me when I get “if you take care of your cooling system you wouldn’t have these problems” when fluids and service performed religiously and it’s driven lightly, pita to find decent parts I feel. My 96 actually does have the temp sensor in the back of the head and I lightly read about that, am I to just loosen that while filling which would allow the air to escape? And no the the heater valve is still in the Jeep and is functioning properly. All hoses and the valve itself are new.

Jim Malcolm

Just loosen the plug, air and eventually coolant will come out quite easily... :-)

Another thing, I bet you don't have the "front cover"... I don't know what it's called. Goes underneath the radiator, above the steering box, to prevent air from coming up under the front of the engine and reducing the pressure differential through the radiator. Sure as heck can't find a picture right now; it's just that pressed fiber crap or plastic like the wheel liners. About 12-18" deep, spans frame rail to frame rail.

Jim Malcolm

https://www.cherokeeforum.com/f2/rub...-shield-11180/

Is2k

Sorry if this is a ridiculous question but I’m assuming you loosen the plug while it’s running and during the usual fill process? And I have the clips in the front crossmember but no guard haha.

Jim Malcolm

I guess it depends where you are in the process. Doing it while warm is gushing enough that I can't imagine doing it while running. I foresee a fountain if you did. I've always done it as that last little bit. Fill and run it like you normally would. After you think you got all the air out, remove the plug while nose-down and in my experience, the air escapes and coolant quickly follows with nothing else needed.

I doubt there are few splash guards still on the road. Shouldn't be too hard to fab something up, even just cardboard and duct tape to perform a test.

I still feel that switching to an aluminum radiator will reduce your operating temperature.

Is2k

Awesome we’ll give it a shot tomorrow, ordered an aluminum from autozone as well as a different water pump and they’ll be here tomorrow, figured I’d get two birds stoned with the same joint and see what happens. The lifetime warranty is nice haha.

MrTodd

The only other thing I can think of after reading all of the above posts is......belt tension. I just purchased this tension gauge ( ) to verify proper tension on a cooling system I am rebuilding in my 99 XJ. The FSM specifically calls this out in the installation proceedures.

Todd