Running hot? Surprising results from easy - bootleg flush

[Manhattan]

As you guys who've been here for a few years have heard, I've had tons of problems getting Bushwood to run at normal operating temps. But this was fixed (finally!) a few months ago.

Last month, I went on a 1,300 mile road trip with no problems. I've driven the Jeep hundreds of miles since then with no problems.

However, Wednesday after a bout 450 miles into a 1,200 mile road trip, the motor started running hot - about 20 degrees above normal.

I took it easy till I got to Richmond - my halfway/turnaround point. During the two days in Richmond, every time the RPM got near 2,500, it would get hot...

Here's the surprisingly easy fix - it was one of those "can't see it helping but why not" kind of fixes...

We took the thermostat out - about a 4 month old unit, left the neck off, put a garden hose in the radiator, turned the water and the motor on and let it run for 15-20 minutes. The water just ran off the block and washed the remaining antifreeze off the Jeep... (the bootleg flush)

Then we put a new 180 degree thermostat in, new gasket, put it all back together... drove 600 miles and the temp never quite got to the mid/normal point! And I had the AC on! And I was going 75 mph!!!

I'll remember that next time I say "why can't it ever be easy?"

[woodybeone]

Trapped air can also cause an engine to run hot.

[Manhattan]

Yeah, that was on the list of things that could've caused the quick fix to work. I suspect that the thermotsat hadn't failed - it was pretty new. I'm guessing that some debri (gasket material) had clogged the thermostat or something else - or - somehow, air had gotten into the system.