coolant slowly disappears?

[torque]

when I was looking over the cherokee to buy it the reservoir was above the ad but below the full, closer to the add. When I test drove it there were no signs of heating up so I just remembered to bring some with me when I picked it up.

On the drive home the temp hung right around 210* mixture of highway and rural routes and some stop and go too. it idles and drives at 210* never goes above 215 or so.

Tonight I did the basic tune up; plugs, cap rotor and wires (crossed the 5 and 6 wires somehow:confused: but got that figured out real quick) and I noticed that the coolant was right back at the same level. I have put 135 miles on since I bought it.

There are no puddles under it
no oil in the antifreeze or vice versa
ran it for like a minute with the cap off and it started to look like it was gonna overflow the radiator so I put the cap on (we have a bunch of cats around and I didn't want any getting sick)
no smell in the exhaust, no white smoke

Also, please bear with me, I am not a mechanic I have basic car knowledge but am no expert.

[Mudderoy]

when I was looking over the cherokee to buy it the reservoir was above the ad but below the full, closer to the add. When I test drove it there were no signs of heating up so I just remembered to bring some with me when I picked it up.

On the drive home the temp hung right around 210* mixture of highway and rural routes and some stop and go too. it idles and drives at 210* never goes above 215 or so.

Tonight I did the basic tune up; plugs, cap rotor and wires (crossed the 5 and 6 wires somehow:confused: but got that figured out real quick) and I noticed that the coolant was right back at the same level. I have put 135 miles on since I bought it.

There are no puddles under it
no oil in the antifreeze or vice versa
ran it for like a minute with the cap off and it started to look like it was gonna overflow the radiator so I put the cap on (we have a bunch of cats around and I didn't want any getting sick)
no smell in the exhaust, no white smoke

Also, please bear with me, I am not a mechanic I have basic car knowledge but am no expert.

I had an issue with a replacement electric fan that rubbed a tiny hole in a couple of fins. It wasn't enough to leak on the ground but just enough to make an area the size of a grapefruit wet on the surface of the back of the radiator. The coolant would leak a little and evaporate.

[torque]

I was under there for a good while and went for a drive and then checked under again, looked at the hoses and the radiator. I think that at some point the PO used stop leak of some sort in the radiator... but now I cant go back out and check because it is pouring outside.

[Mudderoy]

I was under there for a good while and went for a drive and then checked under again, looked at the hoses and the radiator. I think that at some point the PO used stop leak of some sort in the radiator... but now I cant go back out and check because it is pouring outside.

I think I saw the wet spot on my radiator by shining a flashlight through the fan blades of the electric fan. If it isn't running hot etc... I wouldn't do the stop leak until you're certain you have a leak.

Oh I know you might be able to bypass the heater core and see if that is where the leak is.

[torque]

Well, I read the other post about slow coolant loss, and I am getting a radiator cap tomorrow and try that first.

then I guess I will start shining a flashlight through my radiator and fan blades, going to fully inspect the hoses again.

I really want to avoid garage work until it becomes a last resort.

I welcome any advice and tests I can do in my driveway before going that route.

like how do I bypass the heater core to see if that is where the leak is?

[4.3LXJ]

You would smell the leak in the cab if it was the heater core when you turn on the fan.

[torque]

i don't smell any coolant in the cab, and I did run the heater just to check it.

Thanks for the help guys, keep the advice coming and I will be under the hood tomorrow after work, I will be on here sporadically between 6 and 2:30 central time and will check in before I prop the hood tomorrow night and agin at supper time for updates. thatnk again for the help it is really appreciated.

I hate knowing that there is a problem and not knowing how to fix it. once I find the problem and the fix all is well. I do find it relaxing to turn wrenches, just diagnosing things makes me nervous.

[bigjim350]

It could have just been too full in the rad and motor. And when it heats up and gets under pressure, it spits the excess coolant out of the overflow drain on the coolant bottle. Just a guess

[torque]

That would be awesome, I would be ok with that!

when it is at operating temperature wouldn't the overflow bottle have coolant in though?
as it is now the overflow bottle is rigt at the add mark, which is right about where it was when I first looked at the jeep...

I just had the dumbest thought, what if the reservoir was cracket right above that line where the coolant seems to magically stop at?

I will be checking as much of the cooling system as possible tonight, stopping for a haynes manual after work.

[torque]

OK, so I went and got the radiator cap, put it on and filled the reservoir and drove about 25 miles or so... coolant level has not moved. May be too soon to say but perhaps I got lucky!

Thanks everyone for the help and hopefully I don't have to re-visit this.

[BigJeepBigJeep]

If anything you can pinch the reservoir line closed with some plastic pliers and use a pressure tester on the radiator to see if you have a leak anywhere. Just in case. Those tools can be rented at your local autozone if you don't own them.

Sent from my SGH-T839 using Tapatalk

[torque]

hope it doesn't double post but I talked to a guy at work and he has the tool so I am going to see him monday and he will bring it in and I can check it.