Driving the UACJ-6D 800 Miles to Moab With No Cooling FanPosted in Features on April 17, 2019
I didn’t always wait until the last minute to start my school assignments when I was a kid, but I do remember saying to myself more often than not, “It’s only 8 o’clock. If I start my project in 30 minutes I’ll be done by midnight and can turn it in tomorrow.”
So it should surprise nobody (myself least of all) that the day I was set to depart in the UACJ-6D for Moab I was still in the middle of installing a snazzy new UMP air filter that I’d had in my possession for over a month. “It’s OK,” I reassured myself. “If I go to install that filter next week I’ll still have a few days to get it done before Moab.” You know the drill.
It’s not that I don’t like working on my Jeep. Quite the contrary. I’d rather be wrenching that working at the computer any old day of the week. But what caused my procrastination this time was that I didn’t have a real clear vision of how I was gonna cram 10 pounds of filter into a 5 pound package.
I eventually got ’er done (quite cleanly, if I do say so myself) and hurriedly reinstalled all the electronic stuff I had to remove to fit the filter housing under the dash where it could suck a steady diet of clean, cold air. Then I packed the Jeep in record time, grabbed some clothes and winter gear for me and my 12-year-old son, Caelin, busted him out of school a couple hours early, and hit the road straight for Moab.
But as we began climbing grades out of San Diego I noticed something. The temperature on the Cummins R2.8 Murphy Gauge was higher than I remembered seeing it when the ambient air temps were that cool. On big grades the temp gauge was scraping 230 degrees, while before I would hardly crack 205. Normally I’d suspect coolant level or some other malady, but in this case my rational brain was telling me things like, “Oh, it’s just the new filter not playing nice with the engine. Pull over and check it later.” I said that to myself literally the whole way to Moab.
We ran the whole trip at 65-75 mph with me perseverating on the temperature gauge, watching it spike on grades when the little turbodiesel was getting the spurs put to it, but then forgetting about it as the coolant temp settled back down to normal levels on the flat. Caelin and I soldiered on, stopping in Cedar City for the night, then hitting the road the next day and continuing the whole saga over: grade, throttle, temp, summit, downhill, cool, just keep driving … until.
Finally, after pulling of exit 182 from I-70, we stopped at the off-ramp to take a photo of the UACJ-6D next to the “Moab” sign. As I was hopping out, I figured I’d let the little diesel idle to cool down a bit. But then I noticed the temperature wasn’t going down like it normally would at idle. In fact, it was climbing. I popped the hood and jiggled the wires on the electric cooling fan relay, and sure enough: zzzzzzzznnnnnn, the fan sprang to life and the coolant temp plummeted right down to 172 degrees.
There's probably some lesson about thoroughly checking into the problem when I first noticed it, but I'll stop and think about it tomorrow.