Hi all,

I recently purchased a 1996 XJ 4x4 with the 4.0. 146K miles, no rust. It's in incredible shape inside and out with every single maintenance record since brand new, including the original window sticker and dealership paperwork. It has a brand new RC 3" lift with pro comp wheels and BFG KO2s.

I was changing the fuel filter today and noticed the coolant reservoir was just about empty! I had the oil changed about a week ago (approx 50-75 miles since then) and fluid levels were great. I've never had any overheating issues and the needle on the temp gauge has never crossed over the halfway mark. I have no puddles or obvious leaks, no smokey exhaust, no sweet smell through the vents and the heat works great. However, as I was under the car I noticed a small drop of green liquid on the bottom of my front passenger side shock tower, near the top of the coil spring. This area is directly below the reservoir so I took my reservoir out and did not notice any wetness or obvious signs of a leak. There was a tiny drop of coolant on the inside of a washer that secures the reservoir but that's it. I checked the corners of the radiator and did not notice any pinhole leaks, as well as the water pump weep hole. My only guess is a hairline crack in the reservoir which is allowing coolant to leak and evaporate while the engine is running. Any ideas? I love this thing want to keep it in prime shape.

Here are some pics since this is my first post.
http://imgur.com/a/Nm6ikVD

 

Could be a loose hose clamp or a cracked reservoir as they can get brittle with age. I broke atleast two at the yards trying to remove them. Fingers went right thru like they were eggshells.

 

Visit your parts store and rent a coolant system pressure tester or have a shop do it.

No other real way of finding small leaks if you have one.

 

I didn't notice any obvious signs of cracking or general aging on the reservoir bottle. However, the coolant loss seemed to start when I placed a hose clamp over the feeder line from the radiator to the reservoir. I noticed the hose on the reservoir side did not have a clamp on it and could come off rather easily. I don't think it would be possible for a clamp to cause some type of coolant loss since the clamp was over the spout of the reservoir, preventing any type of collapse. I'm gonna buy a new radiator cap and refill with coolant to get an idea on how substantial the leak is. May buy some dye and a UV light as well yo assist in tracking it down.

 

agreed, I had a tiny split in the radiator seam at the front, no coolant trail, cannot see this spot at all, pressure test reveals all

or switch engine off and listen for a hiss, as coolant temp rises for a couple of mins

a universal pressurising device can be home built with a bike inner tube, pump, and some clamps

 

Thank you everyone for the replies. I refilled the reservoir and drove about 15 miles. I now noticed a small bit of coolant right that seemed to be coming from a heater hose. See the attached pics. Could this hose be causing such a large loss?

 

That hose is your heater hose and yes it can. Its under a lot of pressure. So either the hose is bad, the clamp is bad, or the fitting is bad. Or all 3 lol.

I personally hate those spring clamps and always switch out for a worm clamp.

 

I bet there's a leak so small that it evaporates before it's able to make any kind of mess.

 

I'm just glad I found it! Do you happen to know what heater hose that is? I see it goes to the heater control valve and mounts to the top of it. The hose is 5/8"x11/16". I didn't see any that size on Rock Auto

 

The heater hoses are under the heat and air conditioning section

https://www.rockauto.com/en/catalog/...se+/+pipe,6892

 

I saw those, I just didn't see any that were 5/8"x11/16". Sorry, I'm brand new to XJs and constantly working on increasing my maintenance knowledge

 

This - 1000x this! I wasted hours of my life on chasing a leak that I found in seconds with the pressure tester - free loaner tool from Autozone.

That engine and compartment look beautiful - I'm jealous. I'd love to find a late year 4wd 5spd 96 with no rust, low miles and a great maintenance history. I love the older interior style and the late year 96's have that, plus ODB2. Great find!!

 

Can anybody shed some light on what heater hose specifically that is? I can't find the size (5/8"x11/16")

 

It's a chunk of standard 5/8 heater hose you can buy in ANY auto parts store, for cripes sake! Absolutely nothing special. AND get rid of those spring-action clamps! Use new worm-drive clamps. You can eliminate that heater control valve and run both hoses direct to the heater core. Just cap off the vacuum line.

 

Yeah this!
Just one other thing to be careful of.
When taking the hose off of your heater core inlets, be gentle. More than likely your heater core is old, and if you tug on those hose to hard you will destroy it. Then it is a 10 hour repair to replace the heater core.
My suggestion would be to cut the hoses off (if you are replacing them) with a utility knife, and to support the core end till they are cut off.