apac020

I bought my 95 xj a few years ago and it always ran a bit warm. Last year I overhauled the cooling system by:

Replacing the fan clutch, thermostat and water pump
Flushing the cooling system (hose back flush followed by several fill/run/drain with distilled water)
Filling with Zerex G05 50/50 with distilled water
Checked that the lower radiator hose has a spring

The good news is that I'm running 210* almost all the time now, even with AC on. Around town, highway driving, and wheeling are fine. I was just in Moab and ran some pretty hot trails without seeing temps climb over 220. Electric fan was kicking on correctly, from what I could tell.

However, I live in Colorado and a lot of highway passes have very steep grades. With a 5-speed, 33s and 4.56 gears, and fully loaded with the girl, kid, tools/equipment and camping gear, I have to stay in 3rd gear at 3000+ RPMs to stay at 50 mph. AC is off. There is a gradual heat soak while climbing - starts at 210 and keeps rising unless I either reach the top of the pass, stop and let it cool, or lower my RPMs. I've never seen it redline, but today I watched it get to the right "hash" mark on the old gauges, which I think is about 235*.

Even more odd was the outside temp on the pass was maybe 65*.

So what can I do to better handle temps under extreme loads? Hood vents? Better radiator (mine is stock)? Or is there a problem here I'm not aware of?

djb383

The one component who's main/primary function is to remove heat from coolant is the radiator.......has that been replaced? U can not clear a solid plug from a radiator with a garden hose. A rad shop must separate the tanks from the core and "rod" the core out......or buy a new rad.

apac020

Nope, not yet. I'd have thought that I would have issues with normal highway driving in 90F weather if the radiator was plugged. As far as I know, the rad is stock. When I flushed the system everything came out surprisingly clean.

djb383

With regard to the rad, the bottom half of the rad (the tubes) can be completely plugged and the upper half can be clean and flowing freely. U stick a hose in the top of the rad and clean/clear water flushes out the bottom via the top half of the rad that is clean/clear. Nothing flows thru the bottom half so u only have half a rad flowing coolant/dissipating heat. U can not see down low inside the XJ rad so again, the only way to tell if there is blockage is to separate the tanks from the core. That's a job for the rad shop. +/-$100 buys a new rad.

F1Addict

I was having the same problem, constantly hovering around the upper end of the temp gauge up passes and on slow, steep trails. I overhauled the system (replaced hoses, flushed system, replaced reservoir and cap, replaced thermostat, fan clutch and water pump) which helped a lot but didn't completely cure my overheating issues. It would still flirt with the upper end of the gauge on steep passes. I replaced the radiator last winter and returned to the mountains over Memorial Day weekend to test it out. Never saw anything above 220º no matter what I did.

While it never got hot, I did notice the parasitic loss from the new fan clutch going up passes. I plan on replacing it with a dual e-fan in the near future.

BlueRidgeMark

Does anybody rod radiators theses days? New ones are probably cheaper.

apac, one last thing you can try is the Amway flush. Find an Amway dealer near you and buy a package of their laundry detergent, SA8. Put a quarter cup in your radiator and run it for a month or so. It can't hurt your cooling system, unlike some detergents on the market.

Then do a regular flush & fill, and see how things go. If it works, you saved the price and hassle of a radiator flush. If it doesn't, well, you'll be putting your new radiator into a clean system.

No, I don't sell the stuff.

Travis88XJ

I would check the radiator as well, because I use to have a heck of a time going up to the Eisenhower /Johnson tunnel, Vail pass and Rabbit ears pass and get real close to overheating. Then I replaced my radiator with a bigger one and replaced my coolant tank (closed system) plus added Hood vents and I haven't gone close to overheating.

djb383

Any rad shop will rod any rad out, as long as there is enough of the rad left to work with.....I was quoted $65 and up, depending on what else it needed, for our factory original rad. Any tube that has a leak, the rad shop will plug it off. Obviously any tube(s) that is/are plugged off reduce the rads efficiency.

A new XJ rad is dirt cheap and it's probably a toss up between repair the old rad or buy a new rad. There are lots of rads out there (other vehicles) that r +/-$500, so rodding one of those rads out can be a substantial savings over buying new.

md21722

Right this isn't a German import where the radiator is north of $500. Jeep radiators can be had for $100-110 from Auto Zone, etc with lifetime limited warranty. The quick first thing you can do first is inspect the condenser and radiator for air blockage. Lots of sand, dust, and bugs will cut way into the cooling capacity of radiator that has no internal blockage. Personally, with iron block and head I'd stick to Conventional Green antifreeze and change it and the thermostat (from dealer) every 2 years. If your hoses are original I'd seriously consider changing them. They tend to deteriorate from the inside out. They won't help your cooling problems, but fresh hoses are good protection from having one fail.

ksrummel

Order one from advancedautoparts.com an pick up in store. Use the code TRT41. It's 40 off of a 100. Should be able to get a new radiator for sixty something.

BlueRidgeMark

Yep, I know shops still do it. My question is, why would anyone bother?