2012 JK Coolant dripping onto front axle

[codesertrat]

On my 2012 JK, I noticed engine coolant dripping onto the front axle from the overflow tank spout right above it when we were out exploring in the mountains a couple of weeks ago. The coolant level in the overflow tank was a bit too high and sloshing out the spout.

I also noticed that the coolant in the engine was audibly boiling when shut-off. I was about to burst a blood vessel thinking that I had a blown head gasket (dealer just swapped out the LH cylinder head a few months ago), but figured I'd better do some basic troubleshooting first. When it cooled off, I removed and pressure tested the radiator cap, which held no pressure at all. Close inspection showed that the gasket was very worn and coming apart. Replaced it with a new 18psi cap and all is good again.

Just an FYI to y'all as this seemed like very short life (less than 3 years old) for a radiator cap in my experience.

 

[gmwelder86]

Noticed the same thing out in moab. Could smell coolant when bouncing around. Finally tracked it down to the overflow tank. Guessing the coolant would bounce, hit the discharge tube than a little cone out. Doesn't take much to get the burning coolant smell in the air and the hood up to investigate.

 

[comptiger5000]

I never fill the coolant overflow tank all the way on my ZJ (usually aim for it sitting at the full mark when hot, which is about 1/2 when cold in the summer), as it has the same slosh problem and ends up dripping coolant out of the overflow tube.

Radiator caps definitely do wear out, although their lifespan is usually more than 3 years (but it seems to vary). The easy way to confirm that it's still holding pressure properly is to pop the hood with the Jeep hot every once in a while and give the upper rad hose a squeeze to make sure the system has pressure.