i am looking to to upgrade my radiator so the wife can enjoy the comforts of ac during the summer months. the jeeps does OK, but sometimes on long uphill climbs i have to turn the air off as the temps start to climb.

i saw some 2 core aluminum radiators on ebay for under 200 but was wondering if that would be better than what i have now. are the stock radiators a single core or are they two core?

 

The OEM radiator is a single row (not core). What makes a radiator upgrade effective is not the number of rows, but the thickness of the radiator. You can get a two row radiator that actually performs worse than the stock radiator because it's not much thicker than stock and the passages are very small. For this reason, I'd stay away from the cheap Ebay specials. People have bought them and had their problems get worse.

The Champion and CSF radiators get mixed reviews. The good reviews they get come from the fact that they're thicker than stock. The bad reviews usually have to do with build quality and leaks. Morimoto makes a fat radiator, but it's way too expensive to make it worth buying.

The gold standard that I've never seen a complaint about is the Mopar HD radiator, which is a single row that is 5/8" thicker than stock. The big downside to the Mopar radiator is that it's expensive. I'm not sure if they make the HD radiator for the Grand Cherokee.

I have a CSF 3-row in my XJ. It cools great (because it's thick), and I haven't had any issues at all with leaks. I'm in no hurry to swap it, but if I did need a new radiator, I would spring for the Mopar instead.

If you go with a thicker radiator, make sure your motor mounts are in good condition. The thicker radiator leaves less clearance between the radiator and the mechanical fan, so there's less room for the engine to move if the motor mounts are shot. People have spent a lot of money on fancy radiators only to ruin them when the engine shifted forward and put the fan into the fins.

Also, you may want to check your transmission. The transmission is cooled either by running fluid through the radiator or through a transmission cooler right in front of the radiator. If you're experiencing high temps on climbs, it's possible your transmission is overheating and dumping heat into the cooling system.

 

My ZJ was having a few cooling problems. I popped off the metal plate that covers the top of the radiator and found a mess. It's not easy to inspect with the AC coil in front and the plate over the top. I tried to find a full aluminum radiator but couldn't so I settled for this highbred aluminum and plastic. It is a CSF and dry fitting it seems to fit well. It came with everything to hook up to the Transmission as well. I hope the aluminum and plastic doesn't come back to haunt me...

 

What caused that problem with your rad? Is the replacement like OEM or bigger?

 

Yankee car as well as time in Scotland. A lot of winter and wet weather. The CSF doesn't appear to be thicker to me as stated in a earlier reply but it was sold to me as a duel row and like 20-30% better cooling than stock. I don't remember the percentage exactly. It is almost identical in radiator area but the CSF has 4 or 5 more passes I guess you would say. The overheating problem I had wasn't extreme but enough for me to go lookin so I'm pretty confident that this new radiator is going to be a marked difference from what I had...

 

Your problem was related to the loss of the cooling fins. They let most of the air pass thru without transferring heat. This was common on my older Chevy trucks, but they were brass and copper. Aluminum doesn't play well with the salt they use on the roads around here.