stockli

98' aw4 4x4.

I searched and I couldnt find anything that really matched my issue so I figured Id ask here.

The other day I was driving and smelled coolant. I noticed the inner fender well was wet so I popped the hood and saw that some coolant had overflowed out of the reservoir. No big deal, I just replaced the radiator last week so I figured it may have been a little over full. Over the last few days everything was find.

So today I took the jeep for a ride and when I got home I popped the hood to check everything out and noticed the level in my coolant overflow bottle was almost all the way to the top. I sat there and watched the level coming back down as the motor started to cool.

Over the last few months I have replaced the tsat, tsat housing, water pump and now last week the radiator. The jeep does not over heat and generally runs at around 203 but occasionally bumps up to 208-210 and then comes back to 203. I cant figure out what is going on. I dont have any leaks that I could find and the CSF 3 row I installed is less than 1 week old. When the engine is cold the level is right at the full mark.

Anyone ran into this before?

freegdr

never replaced the cap?

ZINGGG

Where is that temperature coming from? Are you just looking at your gauge or using an infrared temperature gun? The gauge is generally not completely accurate. Sounds like you are starting to overheat if that much coolant is pouring into the overflow. How's your fan clutch? Has that ever been replaced?

stockli

I just put a new stant cap on this last fall.

stockli

The fan clutch seems to be operating normally. Stiff when its cold and when its warmed up.

The temp is coming from my digital gauge so its coming off the sending unit.

djb383

There are 2 marks on the bottle, upper/lower. When the motor is COLD, coolant should not be below the lower mark. Rad cap is a 2 way valve and must function properly. Rad cap is key to the coolant recovery system. New stuff can be bad.

djb383

Like 1996 said/asked......has the fan clutch been replaced? Spin test is weak at best and fan clutches slowly deteriorate with age/miles.

Magiksreal

Other than checking that the t-stat isnt in backwards (yes, I've seen that before and still don't know how that happened...) I agree about the cap. I've replaced 3 over 1 1/2 years and counting.

Stuff isn't made to last anymore.

stockli

I am going to pop a new radiator cap on and watch things for a few days.

How much can I expect the coolant to rise in the res? A couple inches?

Where is it on your guys when the jeep is warmed up?

Thanks for the replies. BTW, I went out and squeezed the top hose and could hear the rad cap opening and closing so it seems the cap spring may not be operating correctly.

djb383

Shouldn't hear anything at the cap other than an occasional gurgle seconds after a hot motor is turned off. That's pressurized coolant/air escaping the rad going to the bottle and that's only if the system reaches the release pressure rating of the cap.

Coolant level rise/fall varies. Probably see a larger hi/low coolant level difference in hot weather and less coolant level difference in cold weather.

stockli

Yeah, thats why I am thinking the spring is on its way out. I put my ear right next to the cap and could clearly hear it clicking as I pushed the top hose.

So I got a new cap and Ill toss it on later tonight when she cools down.

freegdr

have it pressure checked, also is there small air bubbles showing in over flo bottle when running at idle

stockli

Good news no bubbles on the res. Also good news, the new radiator cap seems to have taken care of the issue. Stupid crap that is being sold just doesnt last at all.

djb383

Make sure the cap is working in reverse....allowing coolant to return to the rad from the bottle as the motor cools.

stockli

Check its all good.