Overheats Going into the Mountains
Hey all. So two questions, one quick and one not so quick:
1. Has anyone used a coolant system flush product on their XK/WK? Is it safe or am I risking further damage?
2. I think I have a clogged radiator - Would you agree? Short version: Overheats under any kind of sustained load. Long version below.
Could of quick details: My XK eats water pumps. I'm on number...4? in ~100k miles. I am well versed in how to fill/bleed the XK and know the symptoms that are shown when it is not done properly.
Synopsis: Coolant and thermostat was changed ~40k ago. Water pump was about ~15k ago. Last year we attempted to take the XK for a day trip into the mountains, and ventured up I-70 from Denver. XK ended up running very hot (5/8-3/4 on the temp gauge) near the end of the first hill, so I rolled we windows down and ran the heater. Ambient temp was in the 70s. The next hill was worse, so we canceled our trip into the mountains and went home. The jeep was not loaded down by any stretch.
Took a road trip a month ago. Flat highway, 100 degree temps, the XK doesn't really care. I think it is running hotter than normal, but still ok. Took it up into the mountains again today on a road it didn't previously have a problem with - traffic moves well, grade is reasonable, and temps aren't high. Traffic slowed to 25mph on the last hill and the Jeep started to climb in temps again. Once again, not loaded down. I can confirm the fan is coming on appropriately, the system is properly bled/burped, and all fluid levels are good.
I'm fairly convinced the radiator is operating at a very reduced efficiency due to buildup. As long as there is enough airflow and not an engine load, it'll do fine. But as soon as the load is higher than usual and/or airflow becomes even a whiff of an issue, temps start to climb. I'd really like to fix this b/c I want to be able to take day trips into the mountains and explore with my family, and this is the only vehicle that can transport my son. I can confirm the issue is also getting worse.
I'm ready to order a new rad and spend a weekend replacing it myself, unless anybody else has any better ideas. Also, tempted to try a 'flush' product but I'm not sure how bad of an idea that is.
Edit: Order new rad and thermostat.