Noticed coolant reservoir on my XJ was nearly empty about a month ago; filled to the "full" mark. Today, while changing the oil I saw that the reservoir was nearly empty again. I have not noticed any leaks, even though the vehicle was not driven for several weeks at a time over the past few months. Are there any issues particular to the XJ that might have something to do with this? Before I start doing some more general troubleshooting I'd just like to see if this is an issue someone else has encountered.

 

its normal just keep an eye on it if your radiator is full you shouldn't worry because when your engine get hotter your coolant will expand hints the name "over flow tank/reservoir" and as long as your radiator is full on start up you should be good (should but not always sometimes when your engine heats up so does the block and components which means they expand too exposing cracks and stuff so yeah...)

 

coolant bottle level should stay full having the cooling system pressure checked would be a good step here to prevent small leak getting bigger .

 

What year/engine? Always important for us to provide the most accurate replies.

The "level" of coolant in the coolant reservoir will vary between the col and hot markings as the engine heats and cools (by design), but you shouldn't have to be adding coolant.

If you have to add more than a little coolant, you either have a leak or you're burning it. And you better hope it's a leak.

Searching for that leak is absolutely job#1. If you are adding coolant and you cannot find a leak, you could have a problem like a bad head gasket or a cracked cylinder head.

 

^^^^+1 We really need to know at least what year your XJ is.

 

If it's a 2000 or 2001 I'm pretty sure I know where the coolant is going...

 

My mistake, it was rather late at night and I forgot to include some important info. The vehicle is a 95 with the 4.0 L engine.

 

Needs a Compression check and Cooling system pressure check.

Any coolant in the oil? Any oil in the coolant?

 

Oil and coolant aren't mixing. I was worried when I found some brown stuff in the coolant so I took it over to pep boys and they said it definitely wasn't oil, so my guess is it's rust (the vehicle is almost 17 years old, after all). The vehicle also doesn't appear to be burning any coolant (no blue smoke out the exhaust, or smoke of any kind).

 

Ive got a 2001 Cherokee as does my mom, and I check Religiously the Coolant level and Oil color. Possible Head Problems Givin Me Gray Hair.