Antifreeze problem

I have a 2001 XJ I6 4x4. Stock. I have been having an issue with the antifreeze level. It is slowly disappearing. I have no noticeable leaks when at operating temp. I recently changed the oil and it was as clear as can be. I do have an antifreeze smell OUTSIDE when I park. No smell inside. It seems to take a little longer to warm up, but then again it has been extremely cold here. The temp gauge never goes above 190. When I bought the jeep I flushed the radiator and replaced the thermostat. Other than this, it has been a good jeep. Please help, I'm at a loss. Thanks!

How slow is "slowly disappearing"? How do you know it is disappearing - is it missing from the overflow bottle or is the radiator low or ???

Most likely it is a bad radiator cap. It allows the overlow to fill up each heat cycle with hot fluid which tends to evaporate. Get a 16# which is the correct pressure, not 13# like lots of parts books say. The radiator cap should be replaced every two years.

Need to isolate this problem. I had a similar smell on my 99 for a number of months that at first I couldn't find. Then it got a little worse and finally found a leak on the seam of the radiator. It was an OEM 10 year old radiator with 130k on it so didn't owe me anything.

If you get under it with a good light and with the engine hot and under pressure, you may be able to find it.

It is GOOD that you smell antifreeze as that indicates you have an external leak.

As you may or may not know, the 00-01 XJ 4.0 from the factory, came with the "infamous" 0331 cylinder head, which has a casting defect between cylinders 3-4, which make it somewhat prone to cracking. And the #1 symptom of a cracked 0331 head is unexplained coolant loss.

So you want to be sure that all components of your cooling system are in good shape. Radiator, cap, hoses, fan clutch, thermostat, water pump.

Good luck!

Hint: Use an LED light...I've noticed that the coolant is easier to see under that spectrum of light.

Likely a cracked head. Check the bottom side of the oil filler cap for mayonaisse.

ParadiseXJ said:

Hint: Use an LED light...I've noticed that the coolant is easier to see under that spectrum of light.

Click to expand...

From the factory, the 2001 came with a UV dye in it so that it appears under black light to spot leaks.

I have the same basic issue and I just went to Autozone and spent $7 on a bottle of UV dye (assuming that I have no original coolant left) and just tinted it myself. I will drive it around awhile, get it circulated, and then pop a black light into my work lamp and see what glows. If you do have a crack in between 3/4 cylinder, the dye should be pretty visible if you look straight down into the oil filler hole.

Nothing on the bottom of the cap. Oil looks good, no sludge. Antifreeze is clear just disappearing. Carpet is not wet, no smell on the inside. I'm thinking it may be water pump, radiator or a hose somewhere. Please keep the suggestions coming. Thanks

This may be a stretch, but take a look under the overflow hose going from the radiator to the overflow bottle. I don't know if your year has a clamp on it, but my 96 doesn't. After I did my water pump and fan clutch, i was instantly deflated when I saw a a stream of antifreeze shooting up. It turned out to be that hose. Good luck.

I had that same problem for about a year. Slight loss of fluid over time but no sign of a leak or mechanical issue. One hot summer day I finally found it ... very slight steam coming from the front of the radiator. It must have only been leaking under pressure or when hot. I replaced the radiator and the problem was solved.