Re: Going Through a Beater XJ 4.0. Test Drives !!!
The '88 XJ 4.0 made it's first run into the hills yesterday. Tons-o-torque. Smooth as silk. Today it made a highway run. Full throttle acceleration was crazy good ! As I climbed towards my destination, it started warming up. Got to the red zone on the gauge pulling a grade. Pulled over into a parking lot, looked her over. The overflow bottle was empty. Full yesterday. No leaks found. Hoses were very firm. It only took 10 minutes to cool down with the stock aux fan running. So off I went up the next grade at 80% throttle. Runs so nice. Temp rose some, but didn't over heat this time.
All of the time in town, way under 210 on the gauge in 60 degree weather. Pulling the grade out of town, warmer, but didn't overheat, until the long slightly uphill highway at 75mph. Then it over heated to the red zone on the gauge, again. Pulled over on a side road. Climbed a burm nose up, and then tail up to try and purge some air in the cooling system. Nope.
Started running warmer on the highway so I slowed down eventually to 55mph. Temp ran about 20 degrees past 210 if I kept it at 55. Any faster and it would get hotter. So 55 it was.
All new cooling system parts. Radiator was rodded out. Why so hot only at highway speed? Acts like a collapsing hose to me. Well?