Vehicle is as shown:
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=000646
(first link gives vehicle description and usage)
The Jeep Cherokee [XJ] is one stout, long-lived, simple vehicle. But the traditional Jeep need for ground clearance and tight packaging underhood makes for a somewhat undersized radiator/coolant capacity (and AC condensor); about the only complaint from long-term use by users and (severe) abusers. (I have never owned a vehicle with such poor underhood airflow management: winter and summer one is best to wear gloves to open the hood and prop up using gloves or thich rags. There are numerous threads on JEEP forums about installing hood vents).
Knowing this prior to purchase (June 2001) I was determined to really stay on top of this system.
Coolant has been backflushed and changed annually by dealer, and all new hoses and clamps installed in September 2002 at 38k. Ph has remained okay during service intervals, and radiator interior looks close to new.
We make a twice-annual round trip to Chicago (about 2100-miles in four days) at 68-72 mph with AC on constantly. (Again, see above link for other info on additives, oil analysis).
This trip, at 54.5k thru 56.6k also saw the addition of a light-duty Class III hitch to pull a 900-lb trailer at 55-62 mph. There are several grades in both Oklahoma and Missouri which will test a marginal system. The vehicle was on cruise control, in direct third, and left on for all grades. It is an excellent cruise system, and with the motor at approximately 2,500 rpm EXACTLY in the sweet spot for best towing power. Speed was maintained within a mph or two for all grades, and the motor barely breathed hard, even with the torque convertor unlocked.
Man, what a sweetheart vehicle!
Factory ship weight is 2,995 in this configuration, and total combination was 4,800 as per CAT Scale. Too much weight was on rear axle, but ran out of time to install underload leaves on rear spring pack. In other words, vehicle was nose high.
At every stop -- per JEEP recommendations and tons of family experience -- AC was kicked off and hood raised for a 3-5 minute idle to bring temps down gently -- this was the first time that the electric factory auxiliary fan NEVER came back on after first three minutes of idle (programmed to to come on at 225F I am told). Gauge markings corresponded to this.
MPG was 16 for towing average (using FP, of course). Return trip was 18.5 - 21.5)
I have used other cooling system additives in other cars, and in the interval leading to the 38k change had used REDLINE Water Wetter. Although the temp gauge showed no changes, I felt it to be good insurance.
Now, with #258, the coolant temp came down about 3-5 degrees F, and never rose more than the same beyond the 210F factory op-temp. Never seen this before on this Jeep!
The return trip -- without trailer -- featured 72 mph-plus average (versus 68 mph on earlier trips), with some hard charges to get around traffic, and one long run down 75 from McAlester to Atoka behind a local rock hauler at 80 mph.
Temps were at, or beyond 97F past noon every day, with a pretty fair humidity.
Temp gauge never moved up any, and, at 70-72 mph with AC maxed out, temp gauge stayed slightly below indicated op-temp.
Will be backflushing system again in September -- coolant will have about 20k on it -- and it will certainly have #258 in it. (Am looking forward to examining used coolant for signs of scale removal).
REDLINE Water Wetter, while no doubt good, never gave me this. I had used it in the interval leading to 38k, and saw no changes. (And I am NOT knocking it).
(This service interval also saw a change to REDLINE 10W-30/DONALDSON "Endurance" oil filter; 19k B&M auxiliary trans cooler/small power steering cooler and the installation of MAGNEFINE in-line filters on the return lines of both of those systems; about one-inch forward of condensor, partially in-line with mechanical fan.
Both of those systems were treated to A-Rx in recommended amounts for 1k, and "overflushed" with REDLINE in the PS, and SCHAEFFERS #204s in the AT. (AT holds 8.45 qts, after servicing pan and factory screen -- happy to note pan had own drain plug and two magnets already installed -- added one gallon of OTC Dexron, so that unit had a little over four gallons run through it. Rear diff was also A-Rx treated, and switched to REDLINE for third fill after using MOBIL ONE before. [Man, is "The Right Stuff" a great gasket maker, or what!]).
(More of this info -- other changes -- on the JeepsUnlimited Cherokee forum under "Towing: Service [etc] thread I'm still working on).
I believe that #258 is as advertised. I will certainly be using it in all three vehicles henceforth.
[ August 28, 2003, 12:20 PM: Message edited by: TheTanSedan ]
