webhannet

It looks like you may not have the radiator cap fully closed - or perhaps there's a leak in the tube going to the overflow tank. Note the water leak is all coming from the filler area. It's someplace to start.

After my second burping (on the flat, BTW), the heaters performance has continued to improve. More importantly, I have no cold spells in regular use. I'll still go ahead with having the deal flush it - $109. special offer - no mess!

Rednroll

Good call. I'm pretty certain my radiator cap was tight. However, maybe I need a replacement cap? There was some overflow from the cap area when I was burping the system, so that's a possibility as well. I'll let things dry off overnight and inspect the overflow hose and pick up a replacement cap. I suspected the radiator because the heater was working great driving for about 15 minutes down the highway. Then I drive another 15 minutes back home and all my excitement disappeared as my nice hot air blowing out turned luke warm.

I didn't visually inspect my driver side blend door operation yet, but I did turn the temp dial quickly hard left/right a bunch of times and I can hear the blend door opening and closing. So I think that is ok.

dewey7015

I wouldn't recommend the dealership flushing the system...
I went into the dealership with the same issues. They told me that it would be $125.00, and they see this all the time. I had about 1 inch of sludge in the bottom of the overflow tank.
After getting it back from the dealership, nothing changed.
Basically, I undid the clamps leading to the heater core, put an extension hose on one of the hoses, and sprayed the garden hose into the other. Reversed the hoses, and kept going like that until I filled a 5 gallon bucket.
Heat worked back to original specs, for a year. Just did it again last week. It works. 15 minutes total.

webhannet

I have 103K miles, and it's Winter. I would rather let the dealership make their money off me. It's heating well for now - I could still cancel my appointment. I need a new right front bearing hub, so there's another $350. plus. It's tough getting old!

silverbullet88

Can't do the hub yourself? It's quite easy and could save you $$

webhannet

No. I'm neither equipped nor agile enough for such a project. Whenever there's a risk that I might find myself stranded - I withdraw. Hopefully, it won't be a painful repair visit with extra problems to be revealed. It's not needing immediate replacement.

I'm very happy that the JK has held it's style well, and it's looking good. However, it is costing as much in repairs as most of my previous vehicles. I'd hoped "Jeep Tough" would be a slogan in terms of "wear" too.

In my earlier days, I would have traded it, but I'm much more interested in keeping it to an old age. I admire the old Jeeps I see on the road. What I dread most is dealing with the salesmen. I recently overheard the entire conversation between a salesman and a buyer - it was an ugly reminder of how little the process has changed.

Rednroll

Here is where I'm at with my heat problem.

I flushed the heater core. I burbed and topped off the cooling system multiple times. I also went to the power wash and sprayed off my engine and radiator so I could tell if the radiator was leaking or the fluid I was seeing was just overflow spilled when I was burbing the system. It seems my radiator is not leaking like I had suspected. I purchased a replacement radiator cap. Replacing the radiator cap seems to have made a significant improvement but there still seems to be something not quite right.

This is what I'm seeing now. When I'm driving down the road and my engine RPMs are above 2K, Heat is blowing out the vents really good. However, when I'm sitting at a stand still and idling at 700 RPMs, then the heat from my vents will reduce in temperature to a luke warm state.

I'm pretty certain I've gotten all the air out of the cooling system and since my problem now seems to be RPM related, I'm wondering if my water pump needs to be replaced? However, I'm not observing any leaking around the water pump. Also, no sludge or sediments in the overflow.

Any thoughts of what might cause that?

webhannet

Much of what describe sounds like symptoms I had. I'm sorry I'm not more skilled or experienced to help - no one seems to be chiming in with more ideas.

I think you may be over thinking things, but you're getting to a solution. From what you've said, I would focus on the radiator being full AND STAYING FULL. Your continues "topping off" may mean the extra fluid is simply running down to the overflow tank. The coolant level at the radiator cap/neck should only go within one inch pf the top of the neck. You should be finding any excess has gone to the overflow tank. Your overflow tank should be filled within the levels marked on the side.

I know I have a very small and occasional radiator leak. It continued for YEARS until a sharp mechanic saw it. If I told you where it was, you still might not spot it. That is why my system and overflow tank was empty - and no one seems to have looked. I have no drips on the garage floor, so I assume it only leaks under pressure.

I burped twice after driving on separate days - and after bringing the temperature up enough to open the thermostat and cause coolant to flow through the radiator. I believe the coolant inside the engine can flow through the heater without the thermostat having opened. Of course, it's COLD here, so my thermostat may not be opening often. if I'm correct, bubbles trapped in the rest of the system won't reach the radiator to be burped out. Perhaps someone will confirm my theories..

cidd

Two things after you filled the rad did you fill the overflow tank to the full cold mark ? The system should when it gets hot overflow into the tank then as it cools it should suck the coolant back into the system this works the air out and keeps the rad full. You need to check the overflow and make sure that the coolant level is going up when its hot and back down after it cools down if not then the rad cap is bad or you have a leak in the system. If you are not building pressure in the system it will not work properly and not give you even heat and in the summer the temp gauge would climb to hot when you stoped and drop to normal when you started moving. Even a small leak can screw with it working properly

Rednroll

Thanks for the responses. My overflow tank has been filled to the max line all along.

After I posted yesterday, I started my JKU with my remote start and noticed right after starting as I approached, coolant started to drip from the driver's side near the front. I wasn't able to tell where the leak was coming from, hose?, radiator?, overflow?, I just couldn't tell but it was dripping a small amount from that area.

From what you guys described my uneven heat indicates that there is a small leak in the system, thus not keeping constant pressure, and that's likely why I'm likely getting uneven heat?

If that's the case, then I'm back to suspecting my radiator has a small leak in it but I need to try and trace down that intermittent small leak I observed yesterday.