So my XJ is fine on the highway but tends to get really hot in Stop n go traffic. It also gets about 10 mpg on the highway. I read this is a common problem when the clutch fan goes out but I got the rig second hand and don't have stock fans. They both fire up when you turn the ignition and will stay running at the same rate the entire ride. Seem to be wired directly to the cabin. It appears they are identicle and niether is a clutch fan. Anybody got any idea what's goin on here? Sorry i'm kinda new and don't have much experience with the cooling system (think thats obvious). Here's a couple pics of what's goin on in there.

 

Dual electric fans. Poss out of a Ford Taurus.

 

Yep. Doesn't explain the overheating in stop-and-go, though. Those should be adequate.

What's the coolant look like? If it's not green, it needs to be flushed. A buildup of, well I guess it's rust, will cause the radiator to clog up and reduce it's capacity. Flushing the cooling system might take care of it if it's not horribly clogged up.

 

Not all coolant is green.

And yes those should be good. Could be a stuck or partially opening t-stat too. Water pumps come with 5 or 8 blades. The 5 blades suck. (Napa part uptill about 99 I think).

Had to get it from my mailbox at another place:

Napa was using "max-cool" as a vendor from 2007 to 2009. More than half of the pumps had the wrong size impeller and depending on the engine condition and where it was geographically located (high altitude and center america)the vehicle would have strange temp spikes.